Merge 'upstream/master' into pr-win-erw7

38 files changed, 1973 insertions, 397 deletions

diff --git a/test/README.md b/test/README.md
index 0999f412ac..1a5dc022f4 100644
--- a/test/README.md
+++ b/test/README.md
@@ -1,27 +1,63 @@
 Tests
 =====
 
-Tests are run by `/cmake/RunTests.cmake` file, using `busted`.
+Tests are broadly divided into *unit tests* ([test/unit](https://github.com/neovim/neovim/tree/master/test/unit/)),
+*functional tests* ([test/functional](https://github.com/neovim/neovim/tree/master/test/functional/)),
+and *old tests* ([src/nvim/testdir/](https://github.com/neovim/neovim/tree/master/src/nvim/testdir/)).
 
-For some failures, `.nvimlog` (or `$NVIM_LOG_FILE`) may provide insight. 
+- _Unit_ testing is achieved by compiling the tests as a shared library which is
+  loaded and called by [LuaJit FFI](http://luajit.org/ext_ffi.html).
+- _Functional_ tests are driven by RPC, so they do not require LuaJit (as
+  opposed to Lua).
+
+You can learn the [key concepts of Lua in 15 minutes](http://learnxinyminutes.com/docs/lua/).
+Use any existing test as a template to start writing new tests.
+
+Tests are run by `/cmake/RunTests.cmake` file, using `busted` (a Lua test-runner).
+For some failures, `.nvimlog` (or `$NVIM_LOG_FILE`) may provide insight.
+
+Depending on the presence of binaries (e.g., `xclip`) some tests will be
+ignored. You must compile with libintl to prevent `E319: The command is not
+available in this version` errors.
 
-Depending on the presence of binaries (e.g., `xclip`) some tests will be ignored. You must compile with libintl to prevent `E319: The command is not available in this version` errors.
 
 ---
 
 - [Running tests](#running-tests)
-- [Unit tests](#unit-tests)
+- [Writing tests](#writing-tests)
 - [Lint](#lint)
 - [Environment variables](#environment-variables)
 
 ---
 
+
+Layout
+======
+
+- `/test/benchmark` : benchmarks
+- `/test/functional` : functional tests
+- `/test/unit` : unit tests
+- `/test/config` : contains `*.in` files which are transformed into `*.lua`
+  files using `configure_file` CMake command: this is for acessing CMake
+  variables in lua tests.
+- `/test/includes` : include-files for use by luajit `ffi.cdef` C definitions
+  parser: normally used to make macros not accessible via this mechanism
+  accessible the other way.
+- `/test/*/preload.lua` : modules preloaded by busted `--helper` option
+- `/test/**/helpers.lua` : common utility functions for test code
+- `/test/*/**/*_spec.lua` : actual tests. Files that do not end with
+  `_spec.lua` are libraries like `/test/**/helpers.lua`, except that they have
+  some common topic.
+- `/src/nvim/testdir` : old tests (from Vim)
+
+
 Running tests
--------------
+=============
 
-## Executing Tests
+Executing Tests
+---------------
 
-To run all _non-legacy_ (unit + functional) tests:
+To run all tests (except "old" tests):
 
     make test
 
@@ -33,9 +69,32 @@ To run only _functional_ tests:
 
     make functionaltest
 
----
 
-## Filter Tests
+Legacy tests
+------------
+
+To run all legacy Vim tests:
+
+    make oldtest
+
+To run a *single* legacy test set `TEST_FILE`, for example:
+
+    TEST_FILE=test_syntax.res make oldtest
+
+- The `.res` extension (instead of `.vim`) is required.
+- Specify only the test file name, not the full path.
+
+
+Debugging tests
+---------------
+
+You can set `$GDB` to [run tests under gdbserver](https://github.com/neovim/neovim/pull/1527).
+And if `$VALGRIND` is set it will pass `--vgdb=yes` to valgrind instead of
+starting gdbserver directly.
+
+
+Filtering Tests
+---------------
 
 ### Filter by name
 
@@ -85,58 +144,20 @@ To run only the tagged tests:
 
     TEST_TAG=foo make functionaltest
 
-**NOTES**:
+**NOTE:**
 
-* Tags are mainly used for testing issues (ex: `#1234`), so use the following
-  method.
 * `TEST_FILE` is not a pattern string like `TEST_TAG` or `TEST_FILTER`. The
   given value to `TEST_FILE` must be a path to an existing file.
-* Both `TEST_TAG` and `TEST_FILTER` filter tests by the strings from either
-  `it()` or `describe()` functions.
-
----
-
-### Legacy
-
-To run all legacy (Vim) integration tests:
+* Both `TEST_TAG` and `TEST_FILTER` filter tests by the string descriptions
+  found in `it()` and `describe()`.
 
-    make oldtest
-
-To run a *single* legacy test,  run `make` with `TEST_FILE=test_name.res`. E.g.
-to run `test_syntax.vim`:
-
-    TEST_FILE=test_syntax.res make oldtest
-
--  The `.res` extension (instead of `.vim`) is required.
-- Specify only the test file name, not the full path.
 
-### Functional tests
+Writing tests
+=============
 
-`$GDB` can be set to [run tests under
-gdbserver](https://github.com/neovim/neovim/pull/1527). If `$VALGRIND` is also
-set, it will add the `--vgdb=yes` option to valgrind instead of
-starting gdbserver directly.
-
-Unit tests
+Guidelines
 ----------
 
-Tests are broadly divided into *unit tests*
-([test/unit](https://github.com/neovim/neovim/tree/master/test/unit) directory)
-and *functional tests*
-([test/functional](https://github.com/neovim/neovim/tree/master/test/functional)
-directory). Use any of the existing tests as a template to start writing new
-tests.
-
-- _Unit_ testing is achieved by compiling the tests as a shared library which is
-  loaded and called by LuaJit [FFI](http://luajit.org/ext_ffi.html).
-- _Functional_ tests are driven by RPC, so they do not require LuaJit (as
-  opposed to Lua).
-
-You can learn the [key concepts of Lua in 15
-minutes](http://learnxinyminutes.com/docs/lua/).
-
-## Guidelines for writing tests
-
 - Consider [BDD](http://en.wikipedia.org/wiki/Behavior-driven_development)
   guidelines for organization and readability of tests. Describe what you're
   testing (and the environment if applicable) and create specs that assert its
@@ -174,8 +195,14 @@ minutes](http://learnxinyminutes.com/docs/lua/).
       ([example](https://github.com/neovim/neovim/commit/5c1dc0fbe7388528875aff9d7b5055ad718014de#diff-bf80b24c724b0004e8418102f68b0679R18)).
 - Use `make testlint` for using the shipped luacheck program ([supported by syntastic](https://github.com/scrooloose/syntastic/blob/d6b96c079be137c83009827b543a83aa113cc011/doc/syntastic-checkers.txt#L3546))
   to lint all tests.
+- Really long `source([=[...]=])` blocks may break syntax highlighting. Try
+  `:syntax sync fromstart` to fix it.
 
-### Where tests go
+Where tests go
+--------------
+
+Tests in `/test/unit` and `/test/functional` are divided into groups
+by the semantic component they are testing.
 
 - _Unit tests_
   ([test/unit](https://github.com/neovim/neovim/tree/master/test/unit))  should
@@ -189,33 +216,9 @@ minutes](http://learnxinyminutes.com/docs/lua/).
     - Try to find an existing `test/functional/*/*_spec.lua` group that makes
       sense, before creating a new one.
 
-## Checklist for migrating legacy tests
-
-**Note:** Only "old style" (`src/nvim/testdir/*.in`) legacy tests should be
-converted. Please _do not_ convert "new style" Vim tests
-(`src/nvim/testdir/*.vim`).
-The "new style" Vim tests are faster than the old ones, and converting them
-takes time and effort better spent elsewhere.
-
-- Remove the associated `test.in`, `test.out`, and `test.ok` files from
-  `src/nvim/testdir/`.
-- Make sure the lua test ends in `_spec.lua`.
-- Make sure the test count increases accordingly in the build log.
-- Make sure the new test contains the same control characters (`^]`, ...) as the
-  old test.
-  - Instead of the actual control characters, use an equivalent textual
-    representation (e.g. `<esc>` instead of `^]`). The
-    `scripts/legacy2luatest.pl` script does some of these conversions
-    automatically.
-
-## Tips
-
-- Really long `source([=[...]=])` blocks may break syntax highlighting. Try
-  `:syntax sync fromstart` to fix it.
-
 
 Lint
-----
+====
 
 `make lint` (and `make testlint`) runs [luacheck](https://github.com/mpeterv/luacheck)
 on the test code.
@@ -229,29 +232,9 @@ http://luacheck.readthedocs.io/en/stable/warnings.html
 Ignore the smallest applicable scope (e.g. inside a function, not at the top of
 the file).
 
-Layout
-------
-
-- `/test/benchmark` : benchmarks
-- `/test/functional` : functional tests
-- `/test/unit` : unit tests
-- `/test/config` : contains `*.in` files which are transformed into `*.lua`
-  files using `configure_file` CMake command: this is for acessing CMake
-  variables in lua tests.
-- `/test/includes` : include-files for use by luajit `ffi.cdef` C definitions
-  parser: normally used to make macros not accessible via this mechanism
-  accessible the other way.
-- `/test/*/preload.lua` : modules preloaded by busted `--helper` option
-- `/test/**/helpers.lua` : common utility functions for test code
-- `/test/*/**/*_spec.lua` : actual tests. Files that do not end with
-  `_spec.lua` are libraries like `/test/**/helpers.lua`, except that they have
-  some common topic.
-
-Tests in `/test/unit` and `/test/functional` are normally divided into groups
-by the semantic component they are testing.
 
 Environment variables
----------------------
+=====================
 
 Test behaviour is affected by environment variables. Currently supported 
 (Functional, Unit, Benchmarks) (when Defined; when set to _1_; when defined, 
diff --git a/test/functional/api/version_spec.lua b/test/functional/api/version_spec.lua
index b4ae17d963..bf67d4788b 100644
--- a/test/functional/api/version_spec.lua
+++ b/test/functional/api/version_spec.lua
@@ -2,6 +2,7 @@ local helpers = require('test.functional.helpers')(after_each)
 local mpack = require('mpack')
 local clear, funcs, eq = helpers.clear, helpers.funcs, helpers.eq
 local call = helpers.call
+local meths = helpers.meths
 
 local function read_mpack_file(fname)
   local fd = io.open(fname, 'rb')
@@ -43,7 +44,7 @@ describe("api_info()['version']", function()
 end)
 
 
-describe("api functions", function()
+describe("api metadata", function()
   before_each(clear)
 
   local function name_table(entries)
@@ -87,26 +88,23 @@ describe("api functions", function()
     end
   end
 
-  it("are compatible with old metadata or have new level", function()
-    local api = helpers.call('api_info')
-    local compat  = api.version.api_compatible
-    local api_level = api.version.api_level
-    local stable
+  local api, compat, stable, api_level
+  local old_api = {}
+  setup(function()
+    api = meths.get_api_info()[2]
+    compat  = api.version.api_compatible
+    api_level = api.version.api_level
     if api.version.api_prerelease then
       stable = api_level-1
     else
       stable = api_level
     end
 
-    local funcs_new = name_table(api.functions)
-    local ui_events_new = name_table(api.ui_events)
-    local funcs_compat = {}
-    local ui_events_compat = {}
     for level = compat, stable do
       local path = ('test/functional/fixtures/api_level_'..
                    tostring(level)..'.mpack')
-      local old_api = read_mpack_file(path)
-      if old_api == nil then
+      old_api[level] = read_mpack_file(path)
+      if old_api[level] == nil then
         local errstr = "missing metadata fixture for stable level "..level..". "
         if level == api_level and not api.version.api_prerelease then
           errstr = (errstr.."If NVIM_API_CURRENT was bumped, "..
@@ -116,10 +114,16 @@ describe("api functions", function()
       end
 
       if level == 0 then
-        clean_level_0(old_api)
+        clean_level_0(old_api[level])
       end
+    end
+  end)
 
-      for _,f in ipairs(old_api.functions) do
+  it("functions are compatible with old metadata or have new level", function()
+    local funcs_new = name_table(api.functions)
+    local funcs_compat = {}
+    for level = compat, stable do
+      for _,f in ipairs(old_api[level].functions) do
         if funcs_new[f.name] == nil then
           if f.since >= compat then
             error('function '..f.name..' was removed but exists in level '..
@@ -130,18 +134,7 @@ describe("api functions", function()
              filter_function_metadata(funcs_new[f.name]))
         end
       end
-      funcs_compat[level] = name_table(old_api.functions)
-
-      -- UI events were formalized in level 3
-      if level >= 3 then
-        for _,e in ipairs(old_api.ui_events) do
-          local new_e = ui_events_new[e.name]
-          if new_e ~= nil then
-            check_ui_event_compatible(e, new_e)
-          end
-        end
-        ui_events_compat[level] = name_table(old_api.ui_events)
-      end
+      funcs_compat[level] = name_table(old_api[level].functions)
     end
 
     for _,f in ipairs(api.functions) do
@@ -171,6 +164,22 @@ describe("api functions", function()
         end
       end
     end
+  end)
+
+  it("UI events are compatible with old metadata or have new level", function()
+    local ui_events_new = name_table(api.ui_events)
+    local ui_events_compat = {}
+
+    -- UI events were formalized in level 3
+    for level = 3, stable do
+      for _,e in ipairs(old_api[level].ui_events) do
+        local new_e = ui_events_new[e.name]
+        if new_e ~= nil then
+          check_ui_event_compatible(e, new_e)
+        end
+      end
+      ui_events_compat[level] = name_table(old_api[level].ui_events)
+    end
 
     for _,e in ipairs(api.ui_events) do
       if e.since <= stable then
@@ -197,15 +206,18 @@ describe("api functions", function()
     end
   end)
 
-end)
-
-describe("ui_options in metadata", function()
-  it('are correct', function()
-    -- TODO(bfredl) once a release freezes this into metadata,
-    -- instead check that all old options are present
-    local api = helpers.call('api_info')
-    local options = api.ui_options
-    eq({'rgb', 'ext_cmdline', 'ext_popupmenu',
-        'ext_tabline', 'ext_wildmenu', 'ext_linegrid', 'ext_hlstate'}, options)
+  it("ui_options are preserved from older levels", function()
+    local available_options = {}
+    for _, option in ipairs(api.ui_options) do
+      available_options[option] = true
+    end
+    -- UI options were versioned from level 4
+    for level = 4, stable do
+      for _, option in ipairs(old_api[level].ui_options) do
+        if not available_options[option] then
+          error("UI option "..option.." from stable metadata is missing")
+        end
+      end
+    end
   end)
 end)
diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index a9d137391e..ddf5575e31 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -14,6 +14,7 @@ local ok, nvim_async, feed = helpers.ok, helpers.nvim_async, helpers.feed
 local os_name = helpers.os_name
 local request = helpers.request
 local source = helpers.source
+local next_msg = helpers.next_msg
 
 local expect_err = global_helpers.expect_err
 local format_string = global_helpers.format_string
@@ -46,6 +47,15 @@ describe('API', function()
                request, nil)
   end)
 
+  it('handles errors in async requests', function()
+    local error_types = meths.get_api_info()[2].error_types
+    nvim_async("bogus")
+    eq({'notification', 'nvim_error_event',
+        {error_types.Exception.id, 'Invalid method: nvim_bogus'}}, next_msg())
+    -- error didn't close channel.
+    eq(2, eval('1+1'))
+  end)
+
   describe('nvim_command', function()
     it('works', function()
       local fname = helpers.tmpname()
@@ -1237,7 +1247,7 @@ describe('API', function()
 
   describe('nvim_list_uis', function()
     it('returns empty if --headless', function()
-      -- --embed implies --headless.
+      -- Test runner defaults to --headless.
       eq({}, nvim("list_uis"))
     end)
     it('returns attached UIs', function()
@@ -1269,4 +1279,16 @@ describe('API', function()
     end)
   end)
 
+  describe('nvim_create_namespace', function()
+    it('works', function()
+      eq({}, meths.get_namespaces())
+      eq(1, meths.create_namespace("ns-1"))
+      eq(2, meths.create_namespace("ns-2"))
+      eq(1, meths.create_namespace("ns-1"))
+      eq({["ns-1"]=1, ["ns-2"]=2}, meths.get_namespaces())
+      eq(3, meths.create_namespace(""))
+      eq(4, meths.create_namespace(""))
+      eq({["ns-1"]=1, ["ns-2"]=2}, meths.get_namespaces())
+    end)
+  end)
 end)
diff --git a/test/functional/api/window_spec.lua b/test/functional/api/window_spec.lua
index 27d7aa11b4..4496e1f644 100644
--- a/test/functional/api/window_spec.lua
+++ b/test/functional/api/window_spec.lua
@@ -11,6 +11,7 @@ local NIL = helpers.NIL
 local meth_pcall = helpers.meth_pcall
 local meths = helpers.meths
 local command = helpers.command
+local expect_err = helpers.expect_err
 
 -- check if str is visible at the beginning of some line
 local function is_visible(str)
@@ -31,7 +32,7 @@ local function is_visible(str)
     return false
 end
 
-describe('api/win', function()
+describe('API/win', function()
   before_each(clear)
 
   describe('get_buf', function()
@@ -45,6 +46,21 @@ describe('api/win', function()
     end)
   end)
 
+  describe('set_buf', function()
+    it('works', function()
+      nvim('command', 'new')
+      local windows = nvim('list_wins')
+      neq(window('get_buf', windows[2]), window('get_buf', windows[1]))
+      window('set_buf', windows[2], window('get_buf', windows[1]))
+      eq(window('get_buf', windows[2]), window('get_buf', windows[1]))
+    end)
+
+    it('validates args', function()
+      expect_err('Invalid buffer id$', window, 'set_buf', nvim('get_current_win'), 23)
+      expect_err('Invalid window id$', window, 'set_buf', 23, nvim('get_current_buf'))
+    end)
+  end)
+
   describe('{get,set}_cursor', function()
     it('works', function()
       eq({1, 0}, curwin('get_cursor'))
diff --git a/test/functional/autocmd/cmdline_spec.lua b/test/functional/autocmd/cmdline_spec.lua
index 3f0504d02f..51b7b819e9 100644
--- a/test/functional/autocmd/cmdline_spec.lua
+++ b/test/functional/autocmd/cmdline_spec.lua
@@ -5,6 +5,7 @@ local clear = helpers.clear
 local command = helpers.command
 local eq = helpers.eq
 local expect = helpers.expect
+local eval = helpers.eval
 local next_msg = helpers.next_msg
 local feed = helpers.feed
 local meths = helpers.meths
@@ -63,6 +64,7 @@ describe('cmdline autocommands', function()
     })
     command("autocmd CmdlineEnter * echoerr 'FAIL'")
     command("autocmd CmdlineLeave * echoerr 'very error'")
+
     feed(':')
     screen:expect([[
                                                                               |
@@ -74,6 +76,7 @@ describe('cmdline autocommands', function()
       {2:E5500: autocmd has thrown an exception: Vim(echoerr):FAIL}               |
       :^                                                                       |
     ]])
+
     feed("put ='lorem ipsum'<cr>")
     screen:expect([[
                                                                               |
@@ -86,6 +89,7 @@ describe('cmdline autocommands', function()
       {3:Press ENTER or type command to continue}^                                 |
     ]])
 
+    -- cmdline was still executed
     feed('<cr>')
     screen:expect([[
                                                                               |
@@ -97,6 +101,71 @@ describe('cmdline autocommands', function()
       {1:~                                                                       }|
                                                                               |
     ]])
+
+    command("autocmd CmdlineChanged * echoerr 'change erreor'")
+
+    -- history recall still works
+    feed(":<c-p>")
+    screen:expect([[
+                                                                              |
+      lorem ipsum                                                             |
+      {4:                                                                        }|
+      :                                                                       |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):FAIL}               |
+      :put ='lorem ipsum'                                                     |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum'^                                                     |
+    ]])
+
+    feed("<left>")
+    screen:expect([[
+                                                                              |
+      lorem ipsum                                                             |
+      {4:                                                                        }|
+      :                                                                       |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):FAIL}               |
+      :put ='lorem ipsum'                                                     |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum^'                                                     |
+    ]])
+
+    -- edit still works
+    feed(".")
+    screen:expect([[
+      {4:                                                                        }|
+      :                                                                       |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):FAIL}               |
+      :put ='lorem ipsum'                                                     |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum.'                                                    |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum.^'                                                    |
+    ]])
+
+    feed('<cr>')
+    screen:expect([[
+      :put ='lorem ipsum'                                                     |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum.'                                                    |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):change erreor}      |
+      :put ='lorem ipsum.'                                                    |
+      {2:E5500: autocmd has thrown an exception: Vim(echoerr):very error}         |
+                                                                              |
+      {3:Press ENTER or type command to continue}^                                 |
+    ]])
+
+    -- cmdline was still executed
+    feed('<cr>')
+    screen:expect([[
+                                                                              |
+      lorem ipsum                                                             |
+      ^lorem ipsum.                                                            |
+      {1:~                                                                       }|
+      {1:~                                                                       }|
+      {1:~                                                                       }|
+      {1:~                                                                       }|
+                                                                              |
+    ]])
   end)
 
   it('works with nested cmdline', function()
@@ -115,4 +184,41 @@ describe('cmdline autocommands', function()
     feed('1+2<cr>')
     eq({'notification', 'CmdlineLeave', {{cmdtype='=', cmdlevel=2, abort=false}}}, next_msg())
   end)
+
+  it('supports CmdlineChanged' ,function()
+    command("autocmd CmdlineChanged * call rpcnotify(g:channel, 'CmdlineChanged', v:event, getcmdline())")
+    feed(':')
+    eq({'notification', 'CmdlineEnter', {{cmdtype=':', cmdlevel=1}}}, next_msg())
+    feed('l')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "l"}}, next_msg())
+    feed('e')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "le"}}, next_msg())
+    feed('t')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let"}}, next_msg())
+    feed('<space>')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let "}}, next_msg())
+    feed('x')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x"}}, next_msg())
+    feed('<space>')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x "}}, next_msg())
+    feed('=')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x ="}}, next_msg())
+    feed('<space>')
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x = "}}, next_msg())
+    feed('<c-r>=')
+    eq({'notification', 'CmdlineEnter', {{cmdtype='=', cmdlevel=2}}}, next_msg())
+    feed('1')
+    eq({'notification', 'CmdlineChanged', {{cmdtype='=', cmdlevel=2}, "1"}}, next_msg())
+    feed('+')
+    eq({'notification', 'CmdlineChanged', {{cmdtype='=', cmdlevel=2}, "1+"}}, next_msg())
+    feed('1')
+    eq({'notification', 'CmdlineChanged', {{cmdtype='=', cmdlevel=2}, "1+1"}}, next_msg())
+    feed('<cr>')
+    eq({'notification', 'CmdlineLeave', {{cmdtype='=', cmdlevel=2, abort=false}}}, next_msg())
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x = "}}, next_msg())
+    eq({'notification', 'CmdlineChanged', {{cmdtype=':', cmdlevel=1}, "let x = 2"}}, next_msg())
+    feed('<cr>')
+    eq({'notification', 'CmdlineLeave', {{cmdtype=':', cmdlevel=1, abort=false}}}, next_msg())
+    eq(2, eval('x'))
+  end)
 end)
diff --git a/test/functional/autocmd/termclose_spec.lua b/test/functional/autocmd/termclose_spec.lua
index db4e5379d0..62eac59b16 100644
--- a/test/functional/autocmd/termclose_spec.lua
+++ b/test/functional/autocmd/termclose_spec.lua
@@ -6,6 +6,7 @@ local clear, command, nvim, nvim_dir =
 local eval, eq, retry =
   helpers.eval, helpers.eq, helpers.retry
 local ok = helpers.ok
+local feed = helpers.feed
 local iswin = helpers.iswin
 
 
@@ -87,5 +88,6 @@ describe('TermClose event', function()
 
     command('3bdelete!')
     retry(nil, nil, function() eq('3', eval('g:abuf')) end)
+    feed('<c-c>:qa!<cr>')
   end)
 end)
diff --git a/test/functional/clipboard/clipboard_provider_spec.lua b/test/functional/clipboard/clipboard_provider_spec.lua
index a40c080a6d..2bbc678a02 100644
--- a/test/functional/clipboard/clipboard_provider_spec.lua
+++ b/test/functional/clipboard/clipboard_provider_spec.lua
@@ -3,7 +3,7 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
-local feed_command, expect, eq, eval = helpers.feed_command, helpers.expect, helpers.eq, helpers.eval
+local feed_command, expect, eq, eval, source = helpers.feed_command, helpers.expect, helpers.eq, helpers.eval, helpers.source
 local command = helpers.command
 local meths = helpers.meths
 
@@ -147,6 +147,93 @@ describe('clipboard', function()
     eq('clippy!', eval('provider#clipboard#Executable()'))
     eq('', eval('provider#clipboard#Error()'))
   end)
+
+  it('g:clipboard using VimL functions', function()
+    -- Implements a fake clipboard provider. cache_enabled is meaningless here.
+    source([[let g:clipboard = {
+            \  'name': 'custom',
+            \  'copy': {
+            \     '+': {lines, regtype -> extend(g:, {'dummy_clipboard_plus': [lines, regtype]}) },
+            \     '*': {lines, regtype -> extend(g:, {'dummy_clipboard_star': [lines, regtype]}) },
+            \   },
+            \  'paste': {
+            \     '+': {-> get(g:, 'dummy_clipboard_plus', [])},
+            \     '*': {-> get(g:, 'dummy_clipboard_star', [])},
+            \  },
+            \  'cache_enabled': 1,
+            \}]])
+
+    eq('', eval('provider#clipboard#Error()'))
+    eq('custom', eval('provider#clipboard#Executable()'))
+
+    eq('', eval("getreg('*')"))
+    eq('', eval("getreg('+')"))
+
+    command('call setreg("*", "star")')
+    command('call setreg("+", "plus")')
+    eq('star', eval("getreg('*')"))
+    eq('plus', eval("getreg('+')"))
+
+    command('call setreg("*", "star", "v")')
+    eq({{'star'}, 'v'}, eval("g:dummy_clipboard_star"))
+    command('call setreg("*", "star", "V")')
+    eq({{'star', ''}, 'V'}, eval("g:dummy_clipboard_star"))
+    command('call setreg("*", "star", "b")')
+    eq({{'star', ''}, 'b'}, eval("g:dummy_clipboard_star"))
+  end)
+
+  describe('g:clipboard[paste] VimL function', function()
+    it('can return empty list for empty clipboard', function()
+      source([[let g:dummy_clipboard = []
+              let g:clipboard = {
+              \  'name': 'custom',
+              \  'copy': { '*': {lines, regtype ->  0} },
+              \  'paste': { '*': {-> g:dummy_clipboard} },
+              \}]])
+      eq('', eval('provider#clipboard#Error()'))
+      eq('custom', eval('provider#clipboard#Executable()'))
+      eq('', eval("getreg('*')"))
+    end)
+
+    it('can return a list with a single string', function()
+      source([=[let g:dummy_clipboard = ['hello']
+              let g:clipboard = {
+              \  'name': 'custom',
+              \  'copy': { '*': {lines, regtype ->  0} },
+              \  'paste': { '*': {-> g:dummy_clipboard} },
+              \}]=])
+      eq('', eval('provider#clipboard#Error()'))
+      eq('custom', eval('provider#clipboard#Executable()'))
+
+      eq('hello', eval("getreg('*')"))
+      source([[let g:dummy_clipboard = [''] ]])
+      eq('', eval("getreg('*')"))
+    end)
+
+    it('can return a list of lines if a regtype is provided', function()
+      source([=[let g:dummy_clipboard = [['hello'], 'v']
+              let g:clipboard = {
+              \  'name': 'custom',
+              \  'copy': { '*': {lines, regtype ->  0} },
+              \  'paste': { '*': {-> g:dummy_clipboard} },
+              \}]=])
+      eq('', eval('provider#clipboard#Error()'))
+      eq('custom', eval('provider#clipboard#Executable()'))
+      eq('hello', eval("getreg('*')"))
+    end)
+
+    it('can return a list of lines instead of [lines, regtype]', function()
+      source([=[let g:dummy_clipboard = ['hello', 'v']
+              let g:clipboard = {
+              \  'name': 'custom',
+              \  'copy': { '*': {lines, regtype ->  0} },
+              \  'paste': { '*': {-> g:dummy_clipboard} },
+              \}]=])
+      eq('', eval('provider#clipboard#Error()'))
+      eq('custom', eval('provider#clipboard#Executable()'))
+      eq('hello\nv', eval("getreg('*')"))
+    end)
+  end)
 end)
 
 describe('clipboard', function()
diff --git a/test/functional/core/job_spec.lua b/test/functional/core/job_spec.lua
index 34168e10c2..eb02610df0 100644
--- a/test/functional/core/job_spec.lua
+++ b/test/functional/core/job_spec.lua
@@ -17,6 +17,7 @@ local pathroot = helpers.pathroot
 local nvim_set = helpers.nvim_set
 local expect_twostreams = helpers.expect_twostreams
 local expect_msg_seq = helpers.expect_msg_seq
+local expect_err = helpers.expect_err
 local Screen = require('test.functional.ui.screen')
 
 -- Kill process with given pid
@@ -115,6 +116,17 @@ describe('jobs', function()
     ok(string.find(err, "E475: Invalid argument: expected valid directory$") ~= nil)
   end)
 
+  it('produces error when using non-executable `cwd`', function()
+    if iswin() then return end  -- N/A for Windows
+
+    local dir = 'Xtest_not_executable_dir'
+    mkdir(dir)
+    funcs.setfperm(dir, 'rw-------')
+    expect_err('E475: Invalid argument: expected valid directory$', nvim,
+               'command', "call jobstart('pwd', {'cwd': '" .. dir .. "'})")
+    rmdir(dir)
+  end)
+
   it('returns 0 when it fails to start', function()
     eq("", eval("v:errmsg"))
     feed_command("let g:test_jobid = jobstart([])")
diff --git a/test/functional/core/main_spec.lua b/test/functional/core/main_spec.lua
index cd396ef820..a0981e9207 100644
--- a/test/functional/core/main_spec.lua
+++ b/test/functional/core/main_spec.lua
@@ -77,8 +77,8 @@ describe('Command-line option', function()
                                                 |
                                                 |
       ]], {
-        [1] = {foreground = 4210943, special = Screen.colors.Grey0},
-        [2] = {special = Screen.colors.Grey0, bold = true, reverse = true}
+        [1] = {foreground = 4210943},
+        [2] = {bold = true, reverse = true}
       })
       feed('i:cq<CR>')
       screen:expect([[
diff --git a/test/functional/core/startup_spec.lua b/test/functional/core/startup_spec.lua
index 15121261c7..8edb8fc014 100644
--- a/test/functional/core/startup_spec.lua
+++ b/test/functional/core/startup_spec.lua
@@ -7,12 +7,17 @@ local eq = helpers.eq
 local eval = helpers.eval
 local feed = helpers.feed
 local funcs = helpers.funcs
+local mkdir = helpers.mkdir
 local nvim_prog = helpers.nvim_prog
 local nvim_set = helpers.nvim_set
 local read_file = helpers.read_file
 local retry = helpers.retry
+local rmdir = helpers.rmdir
+local set_session = helpers.set_session
 local sleep = helpers.sleep
+local spawn = helpers.spawn
 local iswin = helpers.iswin
+local write_file = helpers.write_file
 
 describe('startup', function()
   before_each(function()
@@ -204,3 +209,57 @@ describe('startup', function()
   end)
 end)
 
+describe('sysinit', function()
+  local xdgdir = 'Xxdg'
+  local vimdir = 'Xvim'
+  local xhome = 'Xhome'
+  local pathsep = helpers.get_pathsep()
+  local argv = {
+    nvim_prog, '--headless', '--embed', '-i', 'NONE', '-n',
+    '--cmd', 'set nomore undodir=. directory=. belloff='
+  }
+
+  before_each(function()
+    rmdir(xdgdir)
+    rmdir(vimdir)
+    rmdir(xhome)
+
+    mkdir(xdgdir)
+    mkdir(xdgdir .. pathsep .. 'nvim')
+    write_file(table.concat({xdgdir, 'nvim', 'sysinit.vim'}, pathsep), [[
+      let g:loaded = get(g:, "loaded", 0) + 1
+      let g:xdg = 1
+    ]])
+
+    mkdir(vimdir)
+    write_file(table.concat({vimdir, 'sysinit.vim'}, pathsep), [[
+      let g:loaded = get(g:, "loaded", 0) + 1
+      let g:vim = 1
+    ]])
+
+    mkdir(xhome)
+  end)
+  after_each(function()
+    rmdir(xdgdir)
+    rmdir(vimdir)
+    rmdir(xhome)
+  end)
+
+  it('prefers XDG_CONFIG_DIRS over VIM', function()
+    set_session(spawn(argv, nil,
+                      { 'HOME='..xhome,
+                        'XDG_CONFIG_DIRS='..xdgdir,
+                        'VIM='..vimdir }))
+    eq('loaded 1 xdg 1 vim 0',
+       eval('printf("loaded %d xdg %d vim %d", g:loaded, get(g:, "xdg", 0), get(g:, "vim", 0))'))
+  end)
+
+  it('uses VIM if XDG_CONFIG_DIRS unset', function()
+    set_session(spawn(argv, nil,
+                      { 'HOME='..xhome,
+                        'XDG_CONFIG_DIRS=',
+                        'VIM='..vimdir }))
+    eq('loaded 1 xdg 0 vim 1',
+       eval('printf("loaded %d xdg %d vim %d", g:loaded, get(g:, "xdg", 0), get(g:, "vim", 0))'))
+  end)
+end)
diff --git a/test/functional/eval/input_spec.lua b/test/functional/eval/input_spec.lua
index 8c65297ac6..e774b939f7 100644
--- a/test/functional/eval/input_spec.lua
+++ b/test/functional/eval/input_spec.lua
@@ -8,6 +8,7 @@ local clear = helpers.clear
 local source = helpers.source
 local command = helpers.command
 local exc_exec = helpers.exc_exec
+local nvim_async = helpers.nvim_async
 
 local screen
 
@@ -59,6 +60,7 @@ before_each(function()
     RBP3={background=Screen.colors.Green},
     RBP4={background=Screen.colors.Blue},
     SEP={bold = true, reverse = true},
+    CONFIRM={bold = true, foreground = Screen.colors.SeaGreen4},
   })
 end)
 
@@ -439,3 +441,43 @@ describe('inputdialog()', function()
     ]])
   end)
 end)
+
+describe('confirm()', function()
+  it("shows dialog even if :silent #8788", function()
+    command("autocmd BufNewFile * call confirm('test')")
+
+    local function check_and_clear(edit_line)
+      screen:expect([[
+                                 |
+        {SEP:                         }|
+        ]]..edit_line..[[
+        {CONFIRM:test}                     |
+        {CONFIRM:[O]k: }^                   |
+      ]])
+      feed('<cr>')
+      command('redraw')
+      command('bdelete!')
+    end
+
+    -- With shortmess-=F
+    command('set shortmess-=F')
+    feed(':edit foo<cr>')
+    check_and_clear('"foo" [New File]         |\n')
+
+    -- With shortmess+=F
+    command('set shortmess+=F')
+    feed(':edit foo<cr>')
+    check_and_clear(':edit foo                |\n')
+
+    -- With :silent
+    feed(':silent edit foo<cr>')
+    check_and_clear(':silent edit foo         |\n')
+
+    -- With API (via eval/VimL) call and shortmess+=F
+    feed(':call nvim_command("edit x")<cr>')
+    check_and_clear(':call nvim_command("edit |\n')
+
+    nvim_async('command', 'edit x')
+    check_and_clear('                         |\n')
+  end)
+end)
diff --git a/test/functional/eval/timer_spec.lua b/test/functional/eval/timer_spec.lua
index c945f12e0e..124b9625c3 100644
--- a/test/functional/eval/timer_spec.lua
+++ b/test/functional/eval/timer_spec.lua
@@ -82,7 +82,7 @@ describe('timers', function()
     run(nil, nil, nil, 300)
     feed("c")
     local count = eval("g:val")
-    assert(count >= 4, 'expected count >= 4, got: '..tostring(count))
+    assert(count >= 3, 'expected count >= 3, got: '..tostring(count))
     eq(99, eval("g:c"))
   end)
 
@@ -144,8 +144,8 @@ describe('timers', function()
     local count2 = eval("g:val")
     -- when count is eval:ed after timer_stop this should be non-racy
     eq(count, count2)
-    assert(4 <= count and count <= 7,
-           'expected (4 <= count <= 7), got: '..tostring(count))
+    assert(3 <= count and count <= 7,
+           'expected (3 <= count <= 7), got: '..tostring(count))
   end)
 
   it('can be stopped from the handler', function()
@@ -172,8 +172,8 @@ describe('timers', function()
         let g:val2 += 1
       endfunc
     ]])
-    command("call timer_start(50,  'MyHandler', {'repeat': 3})")
-    command("call timer_start(100, 'MyHandler2', {'repeat': 2})")
+    command("call timer_start(20, 'MyHandler',  {'repeat': 3})")
+    command("call timer_start(40, 'MyHandler2', {'repeat': 2})")
     run(nil, nil, nil, 300)
     eq(3,eval("g:val"))
     eq(2,eval("g:val2"))
diff --git a/test/functional/ex_cmds/cmd_map_spec.lua b/test/functional/ex_cmds/cmd_map_spec.lua
index 67b3ab49d6..a5ce1abff7 100644
--- a/test/functional/ex_cmds/cmd_map_spec.lua
+++ b/test/functional/ex_cmds/cmd_map_spec.lua
@@ -29,6 +29,9 @@ describe('mappings with <Cmd>', function()
       [5] = {background = Screen.colors.LightGrey},
       [6] = {foreground = Screen.colors.Blue1},
       [7] = {bold = true, reverse = true},
+      [8] = {background = Screen.colors.WebGray},
+      [9] = {background = Screen.colors.LightMagenta},
+      [10] = {foreground = Screen.colors.Red},
     })
     screen:attach()
 
@@ -656,6 +659,37 @@ describe('mappings with <Cmd>', function()
     eq('n', eval('mode(1)'))
   end)
 
+  it('works in insert completion (Ctrl-X) mode', function()
+    feed('os<c-x><c-n>')
+    screen:expect([[
+      some short lines                                                 |
+      some^                                                             |
+      {8:some           }                                                  |
+      {9:short          }{1:                                                  }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {4:-- Keyword Local completion (^N^P) }{3:match 1 of 2}                  |
+    ]])
+
+    feed('<f3>')
+    eq('ic', eval('m'))
+
+    -- ensure a redraw, this would have moved the cursor
+    -- instead if CTRL-X mode was left.
+    feed('<up>')
+    screen:expect([[
+      some short lines                                                 |
+      some^                                                             |
+      {9:some           }                                                  |
+      {9:short          }{1:                                                  }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {4:-- Keyword Local completion (^N^P) }{10:Back at original}              |
+    ]])
+  end)
+
   it('works in cmdline mode', function()
     feed(':text<F3>')
     eq('c', eval('m'))
diff --git a/test/functional/ex_cmds/debug_spec.lua b/test/functional/ex_cmds/debug_spec.lua
index 5dad8098ea..a4d381d3f1 100644
--- a/test/functional/ex_cmds/debug_spec.lua
+++ b/test/functional/ex_cmds/debug_spec.lua
@@ -7,7 +7,7 @@ describe(':debug', function()
   local screen
   before_each(function()
     clear()
-    screen = Screen.new(50, 14)
+    screen = Screen.new(30, 14)
     screen:set_default_attr_ids({
       [1] = {bold = true, foreground = Screen.colors.Blue1},
       [2] = {bold = true, reverse = true},
@@ -19,92 +19,92 @@ describe(':debug', function()
   it('scrolls messages correctly', function()
     feed(':echoerr bork<cr>')
     screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E121: Undefined variable: bork}                    |
-      {3:E15: Invalid expression: bork}                     |
-      {4:Press ENTER or type command to continue}^           |
+                                    |
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {2:                              }|
+      {3:E121: Undefined variable: bork}|
+                                    |
+      {4:Press ENTER or type command to}|
+      {4: continue}^                     |
     ]])
 
     feed(':debug echo "aa"| echo "bb"<cr>')
     screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E121: Undefined variable: bork}                    |
-      {3:E15: Invalid expression: bork}                     |
-      Entering Debug mode.  Type "cont" to continue.    |
-      cmd: echo "aa"| echo "bb"                         |
-      >^                                                 |
+                                    |
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {2:                              }|
+      {3:E121: Undefined variable: bork}|
+                                    |
+      {4:Press ENTER or type command to}|
+      Entering Debug mode.  Type "co|
+      nt" to continue.              |
+      cmd: echo "aa"| echo "bb"     |
+      >^                             |
     ]])
 
     feed('step<cr>')
     screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E121: Undefined variable: bork}                    |
-      {3:E15: Invalid expression: bork}                     |
-      Entering Debug mode.  Type "cont" to continue.    |
-      cmd: echo "aa"| echo "bb"                         |
-      >step                                             |
-      aa                                                |
-      cmd: echo "bb"                                    |
-      >^                                                 |
+                                    |
+      {1:~                             }|
+      {1:~                             }|
+      {2:                              }|
+      {3:E121: Undefined variable: bork}|
+                                    |
+      {4:Press ENTER or type command to}|
+      Entering Debug mode.  Type "co|
+      nt" to continue.              |
+      cmd: echo "aa"| echo "bb"     |
+      >step                         |
+      aa                            |
+      cmd: echo "bb"                |
+      >^                             |
     ]])
 
     feed('step<cr>')
     screen:expect([[
-                                                        |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {2:                                                  }|
-      {3:E121: Undefined variable: bork}                    |
-      {3:E15: Invalid expression: bork}                     |
-      Entering Debug mode.  Type "cont" to continue.    |
-      cmd: echo "aa"| echo "bb"                         |
-      >step                                             |
-      aa                                                |
-      cmd: echo "bb"                                    |
-      >step                                             |
-      bb                                                |
-      {4:Press ENTER or type command to continue}^           |
+      {2:                              }|
+      {3:E121: Undefined variable: bork}|
+                                    |
+      {4:Press ENTER or type command to}|
+      Entering Debug mode.  Type "co|
+      nt" to continue.              |
+      cmd: echo "aa"| echo "bb"     |
+      >step                         |
+      aa                            |
+      cmd: echo "bb"                |
+      >step                         |
+      bb                            |
+      {4:Press ENTER or type command to}|
+      {4: continue}^                     |
     ]])
 
     feed('<cr>')
     screen:expect([[
-      ^                                                  |
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-      {1:~                                                 }|
-                                                        |
+      ^                              |
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+      {1:~                             }|
+                                    |
     ]])
   end)
 end)
diff --git a/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua b/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
index 577a26178a..3fcffd422f 100644
--- a/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
+++ b/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
@@ -11,6 +11,7 @@ local ok = helpers.ok
 local rmdir = helpers.rmdir
 local set_session = helpers.set_session
 local spawn = helpers.spawn
+local nvim_async = helpers.nvim_async
 
 describe(':recover', function()
   before_each(clear)
@@ -150,5 +151,12 @@ describe('swapfile detection', function()
     feed('e')  -- Chose "Edit" at the swap dialog.
     feed('<c-c>')
     screen2:expect(expected_no_dialog)
+
+    -- With API call and shortmess+=F
+    nvim_async('command', 'edit %')
+    screen2:expect{any=[[Found a swap file by the name ".*]]
+                       ..[[Xtest_swapdialog_dir[/\].*]]..testfile..[[%.swp"]]}
+    feed('e')  -- Chose "Edit" at the swap dialog.
+    feed('<c-c>')
   end)
 end)
diff --git a/test/functional/helpers.lua b/test/functional/helpers.lua
index a51eca7fdc..272b80466c 100644
--- a/test/functional/helpers.lua
+++ b/test/functional/helpers.lua
@@ -1,3 +1,4 @@
+require('vim.compat')
 require('coxpcall')
 local luv = require('luv')
 local lfs = require('lfs')
@@ -300,8 +301,10 @@ end
 -- Calls fn() until it succeeds, up to `max` times or until `max_ms`
 -- milliseconds have passed.
 local function retry(max, max_ms, fn)
+  assert(max == nil or max > 0)
+  assert(max_ms == nil or max_ms > 0)
   local tries = 1
-  local timeout = (max_ms and max_ms > 0) and max_ms or 10000
+  local timeout = (max_ms and max_ms or 10000)
   local start_time = luv.now()
   while true do
     local status, result = pcall(fn)
@@ -755,6 +758,14 @@ return function(after_each)
       end
       check_logs()
       check_cores('build/bin/nvim')
+      if session then
+        local msg = session:next_message(0)
+        if msg then
+          if msg[1] == "notification" and msg[2] == "nvim_error_event" then
+            error(msg[3][2])
+          end
+        end
+      end
     end)
   end
   return module
diff --git a/test/functional/legacy/108_backtrace_debug_commands_spec.lua b/test/functional/legacy/108_backtrace_debug_commands_spec.lua
index 9ace4ef093..1c1a2095d5 100644
--- a/test/functional/legacy/108_backtrace_debug_commands_spec.lua
+++ b/test/functional/legacy/108_backtrace_debug_commands_spec.lua
@@ -121,7 +121,6 @@ describe('108', function()
       Error detected while processing function Foo[2]..Bar[2]..Bazz:
       line    3:
       E121: Undefined variable: var3
-      E15: Invalid expression: var3
       here var3 is defined with "another var":
       another var
 
@@ -129,7 +128,6 @@ describe('108', function()
       Error detected while processing function Foo[2]..Bar:
       line    3:
       E121: Undefined variable: var2
-      E15: Invalid expression: var2
       here var2 is defined with 10:
       10
 
diff --git a/test/functional/provider/python3_spec.lua b/test/functional/provider/python3_spec.lua
index 93ac3ae017..5e73690986 100644
--- a/test/functional/provider/python3_spec.lua
+++ b/test/functional/provider/python3_spec.lua
@@ -2,6 +2,7 @@ local helpers = require('test.functional.helpers')(after_each)
 local eval, command, feed = helpers.eval, helpers.command, helpers.feed
 local eq, clear, insert = helpers.eq, helpers.clear, helpers.insert
 local expect, write_file = helpers.expect, helpers.write_file
+local expect_err = helpers.expect_err
 local feed_command = helpers.feed_command
 local source = helpers.source
 local missing_provider = helpers.missing_provider
@@ -9,7 +10,11 @@ local missing_provider = helpers.missing_provider
 do
   clear()
   if missing_provider('python3') then
-    pending('Python 3 (or the neovim module) is broken/missing', function() end)
+    it(':python3 reports E319 if provider is missing', function()
+      expect_err([[Vim%(python3%):E319: No "python3" provider found.*]],
+                 command, 'python3 print("foo")')
+    end)
+    pending('Python 3 (or the pynvim module) is broken/missing', function() end)
     return
   end
 end
diff --git a/test/functional/provider/python_spec.lua b/test/functional/provider/python_spec.lua
index 2fa74e9644..15df76d2f6 100644
--- a/test/functional/provider/python_spec.lua
+++ b/test/functional/provider/python_spec.lua
@@ -8,6 +8,7 @@ local funcs = helpers.funcs
 local meths = helpers.meths
 local insert = helpers.insert
 local expect = helpers.expect
+local expect_err = helpers.expect_err
 local command = helpers.command
 local exc_exec = helpers.exc_exec
 local write_file = helpers.write_file
@@ -17,7 +18,11 @@ local missing_provider = helpers.missing_provider
 do
   clear()
   if missing_provider('python') then
-    pending('Python 2 (or the neovim module) is broken/missing', function() end)
+    it(':python reports E319 if provider is missing', function()
+      expect_err([[Vim%(python%):E319: No "python" provider found.*]],
+                 command, 'python print("foo")')
+    end)
+    pending('Python 2 (or the pynvim module) is broken/missing', function() end)
     return
   end
 end
diff --git a/test/functional/provider/ruby_spec.lua b/test/functional/provider/ruby_spec.lua
index e049ac7c41..40cfe80b50 100644
--- a/test/functional/provider/ruby_spec.lua
+++ b/test/functional/provider/ruby_spec.lua
@@ -6,6 +6,7 @@ local curbufmeths = helpers.curbufmeths
 local eq = helpers.eq
 local eval = helpers.eval
 local expect = helpers.expect
+local expect_err = helpers.expect_err
 local feed = helpers.feed
 local feed_command = helpers.feed_command
 local funcs = helpers.funcs
@@ -17,6 +18,10 @@ local write_file = helpers.write_file
 do
   clear()
   if missing_provider('ruby') then
+    it(':ruby reports E319 if provider is missing', function()
+      expect_err([[Vim%(ruby%):E319: No "ruby" provider found.*]],
+      command, 'ruby puts "foo"')
+    end)
     pending("Missing neovim RubyGem.", function() end)
     return
   end
diff --git a/test/functional/terminal/helpers.lua b/test/functional/terminal/helpers.lua
index bd24b9785d..ae8d4704e4 100644
--- a/test/functional/terminal/helpers.lua
+++ b/test/functional/terminal/helpers.lua
@@ -52,7 +52,7 @@ local function screen_setup(extra_rows, command, cols)
     [7] = {foreground = 130},
     [8] = {foreground = 15, background = 1}, -- error message
     [9] = {foreground = 4},
-    [10] = {foreground = 2},  -- "Press ENTER" in embedded :terminal session.
+    [10] = {foreground = 121},  -- "Press ENTER" in embedded :terminal session.
   })
 
   screen:attach({rgb=false})
diff --git a/test/functional/terminal/highlight_spec.lua b/test/functional/terminal/highlight_spec.lua
index fddc0bbb71..f33959c58d 100644
--- a/test/functional/terminal/highlight_spec.lua
+++ b/test/functional/terminal/highlight_spec.lua
@@ -120,7 +120,7 @@ describe('terminal window highlighting with custom palette', function()
     clear()
     screen = Screen.new(50, 7)
     screen:set_default_attr_ids({
-      [1] = {foreground = 1193046, special = Screen.colors.Black},
+      [1] = {foreground = tonumber('0x123456')},
       [2] = {foreground = 12},
       [3] = {bold = true, reverse = true},
       [5] = {background = 11},
diff --git a/test/functional/terminal/tui_spec.lua b/test/functional/terminal/tui_spec.lua
index 365bd2a0be..1b4441f25f 100644
--- a/test/functional/terminal/tui_spec.lua
+++ b/test/functional/terminal/tui_spec.lua
@@ -134,15 +134,17 @@ describe('tui', function()
     feed_data('\022\007') -- ctrl+g
     feed_data('\022\022') -- ctrl+v
     feed_data('\022\013') -- ctrl+m
+    local attrs = screen:get_default_attr_ids()
+    attrs[11] = {foreground = 81}
     screen:expect([[
-    {9:^G^V^M}{1: }                                           |
+    {11:^G^V^M}{1: }                                           |
     {4:~                                                 }|
     {4:~                                                 }|
     {4:~                                                 }|
     {5:[No Name] [+]                                     }|
     {3:-- INSERT --}                                      |
     {3:-- TERMINAL --}                                    |
-    ]])
+    ]], attrs)
   end)
 
   it('automatically sends <Paste> for bracketed paste sequences', function()
@@ -205,14 +207,14 @@ describe('tui', function()
     screen:set_option('rgb', true)
     screen:set_default_attr_ids({
       [1] = {reverse = true},
-      [2] = {foreground = 13, special = Screen.colors.Grey0},
-      [3] = {bold = true, reverse = true, special = Screen.colors.Grey0},
+      [2] = {foreground = 13},
+      [3] = {bold = true, reverse = true},
       [4] = {bold = true},
-      [5] = {special = Screen.colors.Grey0, reverse = true, foreground = 4},
-      [6] = {foreground = 4, special = Screen.colors.Grey0},
-      [7] = {special = Screen.colors.Grey0, reverse = true, foreground = Screen.colors.SeaGreen4},
-      [8] = {foreground = Screen.colors.SeaGreen4, special = Screen.colors.Grey0},
-      [9] = {special = Screen.colors.Grey0, bold = true, foreground = Screen.colors.Blue1},
+      [5] = {reverse = true, foreground = 4},
+      [6] = {foreground = 4},
+      [7] = {reverse = true, foreground = Screen.colors.SeaGreen4},
+      [8] = {foreground = Screen.colors.SeaGreen4},
+      [9] = {bold = true, foreground = Screen.colors.Blue1},
     })
 
     feed_data(':hi SpecialKey ctermfg=3 guifg=SeaGreen\n')
diff --git a/test/functional/terminal/window_split_tab_spec.lua b/test/functional/terminal/window_split_tab_spec.lua
index 07cc8020a5..fecffe3295 100644
--- a/test/functional/terminal/window_split_tab_spec.lua
+++ b/test/functional/terminal/window_split_tab_spec.lua
@@ -7,6 +7,7 @@ local command = helpers.command
 local eq = helpers.eq
 local eval = helpers.eval
 local iswin = helpers.iswin
+local retry = helpers.retry
 
 describe('terminal', function()
   local screen
@@ -67,17 +68,22 @@ describe('terminal', function()
   end)
 
   it('forwards resize request to the program', function()
-    feed([[<C-\><C-N>:]])  -- Go to cmdline-mode, so cursor is at bottom.
-    screen:try_resize(screen._width - 3, screen._height - 2)
+    feed([[<C-\><C-N>G:]])  -- Go to cmdline-mode, so cursor is at bottom.
+    local w1, h1 = screen._width - 3, screen._height - 2
+    local w2, h2 = w1 - 6, h1 - 3
 
     if iswin() then
-      -- win: less-precise test, SIGWINCH is noisy there. #7506
-      screen:expect{any='rows: 7, cols: 47'}
-      screen:try_resize(screen._width - 6, screen._height - 3)
-      screen:expect{any='rows: 4, cols: 41'}
+      -- win: SIGWINCH is unreliable, use a weaker test. #7506
+      retry(3, 30000, function()
+        screen:try_resize(w1, h1)
+        screen:expect{any='rows: 7, cols: 47'}
+        screen:try_resize(w2, h2)
+        screen:expect{any='rows: 4, cols: 41'}
+      end)
       return
     end
 
+    screen:try_resize(w1, h1)
     screen:expect([[
       tty ready                                      |
       rows: 7, cols: 47                              |
@@ -88,7 +94,7 @@ describe('terminal', function()
                                                      |
       :^                                              |
     ]])
-    screen:try_resize(screen._width - 6, screen._height - 3)
+    screen:try_resize(w2, h2)
     screen:expect([[
       tty ready                                |
       rows: 7, cols: 47                        |
diff --git a/test/functional/ui/bufhl_spec.lua b/test/functional/ui/bufhl_spec.lua
index 95c9427399..bcccef84b6 100644
--- a/test/functional/ui/bufhl_spec.lua
+++ b/test/functional/ui/bufhl_spec.lua
@@ -3,6 +3,7 @@ local Screen = require('test.functional.ui.screen')
 
 local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
 local command, neq = helpers.command, helpers.neq
+local meths = helpers.meths
 local curbufmeths, eq = helpers.curbufmeths, helpers.eq
 
 describe('Buffer highlighting', function()
@@ -37,8 +38,8 @@ describe('Buffer highlighting', function()
     screen:detach()
   end)
 
-  local add_hl = curbufmeths.add_highlight
-  local clear_hl = curbufmeths.clear_highlight
+  local add_highlight = curbufmeths.add_highlight
+  local clear_namespace = curbufmeths.clear_namespace
 
   it('works', function()
     insert([[
@@ -57,8 +58,8 @@ describe('Buffer highlighting', function()
                                               |
     ]])
 
-    add_hl(-1, "String", 0 , 10, 14)
-    add_hl(-1, "Statement", 1 , 5, -1)
+    add_highlight(-1, "String", 0 , 10, 14)
+    add_highlight(-1, "Statement", 1 , 5, -1)
 
     screen:expect([[
       these are {2:some} lines                    |
@@ -83,7 +84,7 @@ describe('Buffer highlighting', function()
                                               |
     ]])
 
-    clear_hl(-1, 0, -1)
+    clear_namespace(-1, 0, -1)
     screen:expect([[
       these are some lines                    |
       ^                                        |
@@ -96,7 +97,7 @@ describe('Buffer highlighting', function()
     ]])
   end)
 
-  describe('support adding multiple sources', function()
+  describe('support using multiple namespaces', function()
     local id1, id2
     before_each(function()
       insert([[
@@ -106,21 +107,21 @@ describe('Buffer highlighting', function()
         from different sources]])
 
       command("hi ImportantWord gui=bold cterm=bold")
-      id1 = add_hl(0, "ImportantWord", 0, 2, 8)
-      add_hl(id1, "ImportantWord", 1, 12, -1)
-      add_hl(id1, "ImportantWord", 2, 0, 9)
-      add_hl(id1, "ImportantWord", 3, 5, 14)
+      id1 = add_highlight(0, "ImportantWord", 0, 2, 8)
+      add_highlight(id1, "ImportantWord", 1, 12, -1)
+      add_highlight(id1, "ImportantWord", 2, 0, 9)
+      add_highlight(id1, "ImportantWord", 3, 5, 14)
 
       -- add_highlight can be called like this to get a new source
       -- without adding any highlight
-      id2 = add_hl(0, "", 0, 0, 0)
+      id2 = add_highlight(0, "", 0, 0, 0)
       neq(id1, id2)
 
-      add_hl(id2, "Special", 0, 2, 8)
-      add_hl(id2, "Identifier", 1, 3, 8)
-      add_hl(id2, "Special", 1, 14, 20)
-      add_hl(id2, "Underlined", 2, 6, 12)
-      add_hl(id2, "Underlined", 3, 0, 9)
+      add_highlight(id2, "Special", 0, 2, 8)
+      add_highlight(id2, "Identifier", 1, 3, 8)
+      add_highlight(id2, "Special", 1, 14, 20)
+      add_highlight(id2, "Underlined", 2, 6, 12)
+      add_highlight(id2, "Underlined", 3, 0, 9)
 
       screen:expect([[
         a {5:longer} example                        |
@@ -135,7 +136,21 @@ describe('Buffer highlighting', function()
     end)
 
     it('and clearing the first added', function()
-      clear_hl(id1, 0, -1)
+      clear_namespace(id1, 0, -1)
+      screen:expect([[
+        a {4:longer} example                        |
+        in {6:order} to de{4:monstr}ate                 |
+        combin{9:ing hi}ghlights                    |
+        {9:from diff}erent source^s                  |
+        {1:~                                       }|
+        {1:~                                       }|
+        {1:~                                       }|
+                                                |
+      ]])
+    end)
+
+    it('and clearing using deprecated name', function()
+      curbufmeths.clear_highlight(id1, 0, -1)
       screen:expect([[
         a {4:longer} example                        |
         in {6:order} to de{4:monstr}ate                 |
@@ -149,7 +164,7 @@ describe('Buffer highlighting', function()
     end)
 
     it('and clearing the second added', function()
-      clear_hl(id2, 0, -1)
+      clear_namespace(id2, 0, -1)
       screen:expect([[
         a {7:longer} example                        |
         in order to {7:demonstrate}                 |
@@ -163,9 +178,9 @@ describe('Buffer highlighting', function()
     end)
 
     it('and clearing line ranges', function()
-      clear_hl(-1, 0, 1)
-      clear_hl(id1, 1, 2)
-      clear_hl(id2, 2, -1)
+      clear_namespace(-1, 0, 1)
+      clear_namespace(id1, 1, 2)
+      clear_namespace(id2, 2, -1)
       screen:expect([[
         a longer example                        |
         in {6:order} to de{4:monstr}ate                 |
@@ -208,9 +223,9 @@ describe('Buffer highlighting', function()
   it('prioritizes latest added highlight', function()
     insert([[
       three overlapping colors]])
-    add_hl(0, "Identifier", 0, 6, 17)
-    add_hl(0, "String", 0, 14, 23)
-    local id = add_hl(0, "Special", 0, 0, 9)
+    add_highlight(0, "Identifier", 0, 6, 17)
+    add_highlight(0, "String", 0, 14, 23)
+    local id = add_highlight(0, "Special", 0, 0, 9)
 
     screen:expect([[
       {4:three ove}{6:rlapp}{2:ing color}^s                |
@@ -223,7 +238,7 @@ describe('Buffer highlighting', function()
                                               |
     ]])
 
-    clear_hl(id, 0, 1)
+    clear_namespace(id, 0, 1)
     screen:expect([[
       three {6:overlapp}{2:ing color}^s                |
       {1:~                                       }|
@@ -239,8 +254,8 @@ describe('Buffer highlighting', function()
   it('works with multibyte text', function()
     insert([[
       Ta båten över sjön!]])
-    add_hl(-1, "Identifier", 0, 3, 9)
-    add_hl(-1, "String", 0, 16, 21)
+    add_highlight(-1, "Identifier", 0, 3, 9)
+    add_highlight(-1, "String", 0, 16, 21)
 
     screen:expect([[
       Ta {6:båten} över {2:sjön}^!                     |
@@ -257,7 +272,7 @@ describe('Buffer highlighting', function()
   it('works with new syntax groups', function()
     insert([[
       fancy code in a new fancy language]])
-    add_hl(-1, "FancyLangItem", 0, 0, 5)
+    add_highlight(-1, "FancyLangItem", 0, 0, 5)
     screen:expect([[
       fancy code in a new fancy languag^e      |
       {1:~                                       }|
@@ -321,7 +336,7 @@ describe('Buffer highlighting', function()
                                                 |
       ]])
 
-      clear_hl(id1, 0, -1)
+      clear_namespace(id1, 0, -1)
       screen:expect([[
         ^1 + 2                                   |
         3 +                                     |
@@ -449,7 +464,7 @@ describe('Buffer highlighting', function()
                                                 |
       ]])
 
-      clear_hl(-1, 0, -1)
+      clear_namespace(-1, 0, -1)
       screen:expect([[
         ^1 + 2{1:$}                                  |
         3 +{1:$}                                    |
@@ -503,4 +518,13 @@ describe('Buffer highlighting', function()
     end)
   end)
 
+  it('and virtual text use the same namespace counter', function()
+    local set_virtual_text = curbufmeths.set_virtual_text
+    eq(1, add_highlight(0, "String", 0 , 0, -1))
+    eq(2, set_virtual_text(0, 0, {{"= text", "Comment"}}, {}))
+    eq(3, meths.create_namespace("my-ns"))
+    eq(4, add_highlight(0, "String", 0 , 0, -1))
+    eq(5, set_virtual_text(0, 0, {{"= text", "Comment"}}, {}))
+    eq(6, meths.create_namespace("other-ns"))
+  end)
 end)
diff --git a/test/functional/ui/cmdline_spec.lua b/test/functional/ui/cmdline_spec.lua
index 0ebb62f78f..5d112d7f35 100644
--- a/test/functional/ui/cmdline_spec.lua
+++ b/test/functional/ui/cmdline_spec.lua
@@ -117,60 +117,60 @@ local function test_cmdline(linegrid)
     end)
 
     it('but not with scrolled messages', function()
-      screen:try_resize(50,10)
+      screen:try_resize(35,10)
       feed(':echoerr doesnotexist<cr>')
       screen:expect{grid=[[
-                                                          |
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {3:                                                  }|
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {5:Press ENTER or type command to continue}^           |
+                                           |
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {3:                                   }|
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {5:inue}^                               |
       ]]}
       feed(':echoerr doesnotexist<cr>')
       screen:expect{grid=[[
-                                                          |
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {3:                                                  }|
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {5:Press ENTER or type command to continue}^           |
+                                           |
+        {1:~                                  }|
+        {3:                                   }|
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {5:inue}^                               |
       ]]}
 
       feed(':echoerr doesnotexist<cr>')
       screen:expect{grid=[[
-                                                          |
-        {1:~                                                 }|
-        {3:                                                  }|
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {4:E121: Undefined variable: doesnotexist}            |
-        {4:E15: Invalid expression: doesnotexist}             |
-        {5:Press ENTER or type command to continue}^           |
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {4:E121: Undefined variable: doesnotex}|
+        {4:ist}                                |
+        {5:Press ENTER or type command to cont}|
+        {5:inue}^                               |
       ]]}
 
       feed('<cr>')
       screen:expect{grid=[[
-        ^                                                  |
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {1:~                                                 }|
-        {3:n                                                 }|
-                                                          |
+        ^                                   |
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {1:~                                  }|
+        {3:n                                  }|
+                                           |
       ]]}
     end)
   end)
diff --git a/test/functional/ui/diff_spec.lua b/test/functional/ui/diff_spec.lua
new file mode 100644
index 0000000000..8e6756e550
--- /dev/null
+++ b/test/functional/ui/diff_spec.lua
@@ -0,0 +1,959 @@
+local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
+
+local feed = helpers.feed
+local clear = helpers.clear
+local write_file = helpers.write_file
+
+describe('Diff mode screen', function()
+  local fname = 'Xtest-functional-diff-screen-1'
+  local fname_2 = fname .. '.2'
+  local screen
+
+  local reread = function()
+    feed(':e<cr><c-w>w:e<cr><c-w>w')
+  end
+
+  setup(function()
+    clear()
+    os.remove(fname)
+    os.remove(fname_2)
+  end)
+
+  teardown(function()
+    os.remove(fname)
+    os.remove(fname_2)
+  end)
+
+  before_each(function()
+    clear()
+    feed(':e ' .. fname_2 .. '<cr>')
+    feed(':vnew ' .. fname .. '<cr>')
+    feed(':diffthis<cr>')
+    feed('<c-w>w:diffthis<cr><c-w>w')
+
+    screen = Screen.new(40, 16)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [1] = {foreground = Screen.colors.DarkBlue, background = Screen.colors.WebGray},
+      [2] = {background = Screen.colors.LightCyan1, bold = true, foreground = Screen.colors.Blue1},
+      [3] = {reverse = true},
+      [4] = {background = Screen.colors.LightBlue},
+      [5] = {foreground = Screen.colors.DarkBlue, background = Screen.colors.LightGrey},
+      [6] = {bold = true, foreground = Screen.colors.Blue1},
+      [7] = {bold = true, reverse = true},
+      [8] = {bold = true, background = Screen.colors.Red},
+      [9] = {background = Screen.colors.LightMagenta},
+    })
+  end)
+
+  it('Add a line in beginning of file 2', function()
+    write_file(fname, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    write_file(fname_2, "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {1:  }{2:------------------}{3:│}{1:  }{4:0                }|
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:+ }{5:+--  4 lines: 7···}{3:│}{1:+ }{5:+--  4 lines: 7··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:  }{2:------------------}{3:│}{1:  }{4:0                }|
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:+ }{5:+--  4 lines: 7···}{3:│}{1:+ }{5:+--  4 lines: 7··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Add a line in beginning of file 1', function()
+    write_file(fname, "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    reread()
+
+    feed(":set diffopt=filler<cr>")
+    screen:expect([[
+      {1:  }{4:^0                 }{3:│}{1:  }{2:-----------------}|
+      {1:  }1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:+ }{5:+--  4 lines: 7···}{3:│}{1:+ }{5:+--  4 lines: 7··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(":set diffopt+=internal<cr>")
+    screen:expect([[
+      {1:  }{4:^0                 }{3:│}{1:  }{2:-----------------}|
+      {1:  }1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:+ }{5:+--  4 lines: 7···}{3:│}{1:+ }{5:+--  4 lines: 7··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Add a line at the end of file 2', function()
+    write_file(fname, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n", false)
+    reread()
+
+    feed(":set diffopt=filler<cr>")
+    screen:expect([[
+      {1:+ }{5:^+--  4 lines: 1···}{3:│}{1:+ }{5:+--  4 lines: 1··}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{2:------------------}{3:│}{1:  }{4:11               }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(":set diffopt+=internal<cr>")
+    screen:expect([[
+      {1:+ }{5:^+--  4 lines: 1···}{3:│}{1:+ }{5:+--  4 lines: 1··}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{2:------------------}{3:│}{1:  }{4:11               }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Add a line at the end of file 1', function()
+    write_file(fname, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    reread()
+
+    feed(":set diffopt=filler<cr>")
+    screen:expect([[
+      {1:+ }{5:^+--  4 lines: 1···}{3:│}{1:+ }{5:+--  4 lines: 1··}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{4:11                }{3:│}{1:  }{2:-----------------}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(":set diffopt+=internal<cr>")
+    screen:expect([[
+      {1:+ }{5:^+--  4 lines: 1···}{3:│}{1:+ }{5:+--  4 lines: 1··}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{4:11                }{3:│}{1:  }{2:-----------------}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Add a line in the middle of file 2, remove on at the end of file 1', function()
+    write_file(fname, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n4\n5\n6\n7\n8\n9\n10\n", false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }{2:------------------}{3:│}{1:  }{4:4                }|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{4:11                }{3:│}{1:  }{2:-----------------}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }{2:------------------}{3:│}{1:  }{4:4                }|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{4:11                }{3:│}{1:  }{2:-----------------}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Add a line in the middle of file 1, remove on at the end of file 2', function()
+    write_file(fname, "1\n2\n3\n4\n4\n5\n6\n7\n8\n9\n10\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n", false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }{4:4                 }{3:│}{1:  }{2:-----------------}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{2:------------------}{3:│}{1:  }{4:11               }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:  }^1                 {3:│}{1:  }1                |
+      {1:  }2                 {3:│}{1:  }2                |
+      {1:  }3                 {3:│}{1:  }3                |
+      {1:  }4                 {3:│}{1:  }4                |
+      {1:  }{4:4                 }{3:│}{1:  }{2:-----------------}|
+      {1:  }5                 {3:│}{1:  }5                |
+      {1:  }6                 {3:│}{1:  }6                |
+      {1:  }7                 {3:│}{1:  }7                |
+      {1:  }8                 {3:│}{1:  }8                |
+      {1:  }9                 {3:│}{1:  }9                |
+      {1:  }10                {3:│}{1:  }10               |
+      {1:  }{2:------------------}{3:│}{1:  }{4:11               }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  describe('normal/patience/histogram diff algorithm', function()
+    setup(function()
+      local f1 = [[#include <stdio.h>
+
+// Frobs foo heartily
+int frobnitz(int foo)
+{
+    int i;
+    for(i = 0; i < 10; i++)
+    {
+        printf("Your answer is: ");
+        printf("%d\n", foo);
+    }
+}
+
+int fact(int n)
+{
+    if(n > 1)
+    {
+        return fact(n-1) * n;
+    }
+    return 1;
+}
+
+int main(int argc, char **argv)
+{
+    frobnitz(fact(10));
+}]]
+      write_file(fname, f1, false)
+      local f2 = [[#include <stdio.h>
+
+int fib(int n)
+{
+    if(n > 2)
+    {
+        return fib(n-1) + fib(n-2);
+    }
+    return 1;
+}
+
+// Frobs foo heartily
+int frobnitz(int foo)
+{
+    int i;
+    for(i = 0; i < 10; i++)
+    {
+        printf("%d\n", foo);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    frobnitz(fib(10));
+}]]
+      write_file(fname_2, f2, false)
+    end)
+
+    it('diffopt=+algorithm:myers', function()
+      reread()
+      feed(':set diffopt=internal,filler<cr>')
+      screen:expect([[
+        {1:  }^#include <stdio.h>{3:│}{1:  }#include <stdio.h|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{8:// Frobs foo heart}{3:│}{1:  }{8:int fib(int n)}{9:   }|
+        {1:  }{4:int frobnitz(int f}{3:│}{1:  }{2:-----------------}|
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{9:    i}{8:nt i;}{9:        }{3:│}{1:  }{9:    i}{8:f(n > 2)}{9:    }|
+        {1:  }{4:    for(i = 0; i <}{3:│}{1:  }{2:-----------------}|
+        {1:  }    {             {3:│}{1:  }    {            |
+        {1:  }{9:        }{8:printf("Yo}{3:│}{1:  }{9:        }{8:return fi}|
+        {1:  }{4:        printf("%d}{3:│}{1:  }{2:-----------------}|
+        {1:  }    }             {3:│}{1:  }    }            |
+        {1:  }{2:------------------}{3:│}{1:  }{4:    return 1;    }|
+        {1:  }}                 {3:│}{1:  }}                |
+        {1:  }                  {3:│}{1:  }                 |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=internal,filler            |
+      ]])
+
+      feed('G')
+      screen:expect([[
+        {1:  }{2:------------------}{3:│}{1:  }{4:int frobnitz(int }|
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{9:    i}{8:f(n > 1)}{9:     }{3:│}{1:  }{9:    i}{8:nt i;}{9:       }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    for(i = 0; i }|
+        {1:  }    {             {3:│}{1:  }    {            |
+        {1:  }{9:        }{8:return fac}{3:│}{1:  }{9:        }{8:printf("%}|
+        {1:  }    }             {3:│}{1:  }    }            |
+        {1:  }{4:    return 1;     }{3:│}{1:  }{2:-----------------}|
+        {1:  }}                 {3:│}{1:  }}                |
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }int main(int argc,{3:│}{1:  }int main(int argc|
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{9:    frobnitz(f}{8:act}{9:(}{3:│}{1:  }{9:    frobnitz(f}{8:ib}{9:(}|
+        {1:  }^}                 {3:│}{1:  }}                |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=internal,filler            |
+      ]])
+    end)
+
+    it('diffopt+=algorithm:patience', function()
+      reread()
+      feed(':set diffopt=internal,filler,algorithm:patience<cr>')
+      screen:expect([[
+        {1:  }^#include <stdio.h>{3:│}{1:  }#include <stdio.h|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{2:------------------}{3:│}{1:  }{4:int fib(int n)   }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:{                }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    if(n > 2)    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    {            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:        return fi}|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    }            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    return 1;    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:}                }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }// Frobs foo heart{3:│}{1:  }// Frobs foo hear|
+        {1:  }int frobnitz(int f{3:│}{1:  }int frobnitz(int |
+        {1:  }{                 {3:│}{1:  }{                |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+                                                |
+      ]])
+
+      feed('G')
+      screen:expect([[
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{4:int fact(int n)   }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:{                 }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    if(n > 1)     }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    {             }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:        return fac}{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    }             }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    return 1;     }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:}                 }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:                  }{3:│}{1:  }{2:-----------------}|
+        {1:  }int main(int argc,{3:│}{1:  }int main(int argc|
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{9:    frobnitz(f}{8:act}{9:(}{3:│}{1:  }{9:    frobnitz(f}{8:ib}{9:(}|
+        {1:  }^}                 {3:│}{1:  }}                |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+                                                |
+      ]])
+    end)
+
+    it('diffopt+=algorithm:histogram', function()
+      reread()
+      feed(':set diffopt=internal,filler,algorithm:histogram<cr>')
+      screen:expect([[
+        {1:  }^#include <stdio.h>{3:│}{1:  }#include <stdio.h|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{2:------------------}{3:│}{1:  }{4:int fib(int n)   }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:{                }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    if(n > 2)    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    {            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:        return fi}|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    }            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    return 1;    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:}                }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }// Frobs foo heart{3:│}{1:  }// Frobs foo hear|
+        {1:  }int frobnitz(int f{3:│}{1:  }int frobnitz(int |
+        {1:  }{                 {3:│}{1:  }{                |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+                                                |
+      ]])
+
+      feed('G')
+      screen:expect([[
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{4:int fact(int n)   }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:{                 }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    if(n > 1)     }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    {             }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:        return fac}{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    }             }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:    return 1;     }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:}                 }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:                  }{3:│}{1:  }{2:-----------------}|
+        {1:  }int main(int argc,{3:│}{1:  }int main(int argc|
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{9:    frobnitz(f}{8:act}{9:(}{3:│}{1:  }{9:    frobnitz(f}{8:ib}{9:(}|
+        {1:  }^}                 {3:│}{1:  }}                |
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+                                                |
+      ]])
+    end)
+  end)
+
+  describe('diffopt+=indent-heuristic', function()
+    setup(function()
+      local f1 = [[
+  def finalize(values)
+
+    values.each do |v|
+      v.finalize
+    end]]
+      write_file(fname, f1, false)
+      local f2 = [[
+  def finalize(values)
+
+    values.each do |v|
+      v.prepare
+    end
+
+    values.each do |v|
+      v.finalize
+    end]]
+      write_file(fname_2, f2, false)
+      feed(':diffupdate!<cr>')
+    end)
+
+    it('internal', function()
+      reread()
+      feed(":set diffopt=internal,filler<cr>")
+      screen:expect([[
+        {1:  }^def finalize(value{3:│}{1:  }def finalize(valu|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }  values.each do |{3:│}{1:  }  values.each do |
+        {1:  }{2:------------------}{3:│}{1:  }{4:    v.prepare    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:  end            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:  values.each do }|
+        {1:  }    v.finalize    {3:│}{1:  }    v.finalize   |
+        {1:  }  end             {3:│}{1:  }  end            |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=internal,filler            |
+      ]])
+    end)
+
+    it('indent-heuristic', function()
+      reread()
+      feed(':set diffopt=internal,filler,indent-heuristic<cr>')
+      screen:expect([[
+        {1:  }^def finalize(value{3:│}{1:  }def finalize(valu|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{2:------------------}{3:│}{1:  }{4:  values.each do }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    v.prepare    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:  end            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }  values.each do |{3:│}{1:  }  values.each do |
+        {1:  }    v.finalize    {3:│}{1:  }    v.finalize   |
+        {1:  }  end             {3:│}{1:  }  end            |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+                                                |
+      ]])
+    end)
+
+    it('indent-heuristic random order', function()
+      reread()
+      feed(':set diffopt=internal,filler,indent-heuristic,algorithm:patience<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^def finalize(value{3:│}{1:  }def finalize(valu|
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }{2:------------------}{3:│}{1:  }{4:  values.each do }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:    v.prepare    }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:  end            }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }  values.each do |{3:│}{1:  }  values.each do |
+        {1:  }    v.finalize    {3:│}{1:  }    v.finalize   |
+        {1:  }  end             {3:│}{1:  }  end            |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+  end)
+
+  it('Diff the same file', function()
+    write_file(fname, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    write_file(fname_2, "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n", false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {1:+ }{5:^+-- 10 lines: 1···}{3:│}{1:+ }{5:+-- 10 lines: 1··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:+ }{5:^+-- 10 lines: 1···}{3:│}{1:+ }{5:+-- 10 lines: 1··}|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('Diff an empty file', function()
+    write_file(fname, "", false)
+    write_file(fname_2, "", false)
+    reread()
+
+    feed(':set diffopt=filler<cr>')
+    screen:expect([[
+      {1:- }^                  {3:│}{1:- }                 |
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler                     |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:- }^                  {3:│}{1:- }                 |
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  it('diffopt+=icase', function()
+    write_file(fname, "a\nb\ncd\n", false)
+    write_file(fname_2, "A\nb\ncDe\n", false)
+    reread()
+
+    feed(':set diffopt=filler,icase<cr>')
+    screen:expect([[
+      {1:  }^a                 {3:│}{1:  }A                |
+      {1:  }b                 {3:│}{1:  }b                |
+      {1:  }{9:cd                }{3:│}{1:  }{9:cD}{8:e}{9:              }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt=filler,icase               |
+    ]])
+
+    feed(':set diffopt+=internal<cr>')
+    screen:expect([[
+      {1:  }^a                 {3:│}{1:  }A                |
+      {1:  }b                 {3:│}{1:  }b                |
+      {1:  }{9:cd                }{3:│}{1:  }{9:cD}{8:e}{9:              }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+      {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+      :set diffopt+=internal                  |
+    ]])
+  end)
+
+  describe('diffopt+=iwhite', function()
+    setup(function()
+      local f1 = 'int main()\n{\n   printf("Hello, World!");\n   return 0;\n}\n'
+      write_file(fname, f1, false)
+      local f2 = 'int main()\n{\n   if (0)\n   {\n      printf("Hello, World!");\n      return 0;\n   }\n}\n'
+      write_file(fname_2, f2, false)
+      feed(':diffupdate!<cr>')
+    end)
+
+    it('external', function()
+      reread()
+      feed(':set diffopt=filler,iwhite<cr>')
+      screen:expect([[
+        {1:  }^int main()        {3:│}{1:  }int main()       |
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{2:------------------}{3:│}{1:  }{4:   if (0)        }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:   {             }|
+        {1:  }   printf("Hello, {3:│}{1:  }      printf("Hel|
+        {1:  }   return 0;      {3:│}{1:  }      return 0;  |
+        {1:  }{2:------------------}{3:│}{1:  }{4:   }             }|
+        {1:  }}                 {3:│}{1:  }}                |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=filler,iwhite              |
+      ]])
+    end)
+
+    it('internal', function()
+      reread()
+      feed(':set diffopt=filler,iwhite,internal<cr>')
+      screen:expect([[
+        {1:  }^int main()        {3:│}{1:  }int main()       |
+        {1:  }{                 {3:│}{1:  }{                |
+        {1:  }{2:------------------}{3:│}{1:  }{4:   if (0)        }|
+        {1:  }{2:------------------}{3:│}{1:  }{4:   {             }|
+        {1:  }   printf("Hello, {3:│}{1:  }      printf("Hel|
+        {1:  }   return 0;      {3:│}{1:  }      return 0;  |
+        {1:  }{2:------------------}{3:│}{1:  }{4:   }             }|
+        {1:  }}                 {3:│}{1:  }}                |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=filler,iwhite,internal     |
+      ]])
+    end)
+  end)
+
+  describe('diffopt+=iblank', function()
+    setup(function()
+      write_file(fname, 'a\n\n \ncd\nef\nxxx\n', false)
+      write_file(fname_2, 'a\ncd\n\nef\nyyy\n', false)
+      feed(':diffupdate!<cr>')
+    end)
+
+    it('generic', function()
+      reread()
+      feed(':set diffopt=internal,filler,iblank<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }{4:                  }{3:│}{1:  }{2:-----------------}|
+        {1:  }{4:                  }{3:│}{1:  }{2:-----------------}|
+        {1:  }cd                {3:│}{1:  }cd               |
+        {1:  }ef                {3:│}{1:  }                 |
+        {1:  }{8:xxx}{9:               }{3:│}{1:  }ef               |
+        {1:  }{6:~                 }{3:│}{1:  }{8:yyy}{9:              }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :set diffopt=internal,filler,iblank     |
+      ]])
+    end)
+
+    it('diffopt+=iwhite', function()
+      reread()
+      feed(':set diffopt=internal,filler,iblank,iwhite<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }                  {3:│}{1:  }cd               |
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }cd                {3:│}{1:  }ef               |
+        {1:  }ef                {3:│}{1:  }{8:yyy}{9:              }|
+        {1:  }{8:xxx}{9:               }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+
+    it('diffopt+=iwhiteall', function()
+      reread()
+      feed(':set diffopt=internal,filler,iblank,iwhiteall<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }                  {3:│}{1:  }cd               |
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }cd                {3:│}{1:  }ef               |
+        {1:  }ef                {3:│}{1:  }{8:yyy}{9:              }|
+        {1:  }{8:xxx}{9:               }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+
+    it('diffopt+=iwhiteeol', function()
+      reread()
+      feed(':set diffopt=internal,filler,iblank,iwhiteeol<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }                  {3:│}{1:  }cd               |
+        {1:  }                  {3:│}{1:  }                 |
+        {1:  }cd                {3:│}{1:  }ef               |
+        {1:  }ef                {3:│}{1:  }{8:yyy}{9:              }|
+        {1:  }{8:xxx}{9:               }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+  end)
+
+  describe('diffopt+=iwhite{eol,all}', function()
+    setup(function()
+      write_file(fname, 'a \nx\ncd\nef\nxx  xx\nfoo\nbar\n', false)
+      write_file(fname_2, 'a\nx\nc d\n ef\nxx xx\nfoo\n\nbar\n', false)
+      feed(':diffupdate!<cr>')
+    end)
+
+    it('diffopt+=iwhiteeol', function()
+      reread()
+      feed(':set diffopt=internal,filler,iwhiteeol<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }x                 {3:│}{1:  }x                |
+        {1:  }{9:cd                }{3:│}{1:  }{9:c}{8: }{9:d              }|
+        {1:  }{9:ef                }{3:│}{1:  }{8: }{9:ef              }|
+        {1:  }{9:xx }{8: }{9:xx            }{3:│}{1:  }{9:xx xx            }|
+        {1:  }foo               {3:│}{1:  }foo              |
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }bar               {3:│}{1:  }bar              |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+
+    it('diffopt+=iwhiteall', function()
+      reread()
+      feed(':set diffopt=internal,filler,iwhiteall<cr>')
+      feed(':<cr>')
+      screen:expect([[
+        {1:  }^a                 {3:│}{1:  }a                |
+        {1:  }x                 {3:│}{1:  }x                |
+        {1:  }cd                {3:│}{1:  }c d              |
+        {1:  }ef                {3:│}{1:  } ef              |
+        {1:  }xx  xx            {3:│}{1:  }xx xx            |
+        {1:  }foo               {3:│}{1:  }foo              |
+        {1:  }{2:------------------}{3:│}{1:  }{4:                 }|
+        {1:  }bar               {3:│}{1:  }bar              |
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {1:  }{6:~                 }{3:│}{1:  }{6:~                }|
+        {7:<onal-diff-screen-1  }{3:<l-diff-screen-1.2 }|
+        :                                       |
+      ]])
+    end)
+  end)
+end)
diff --git a/test/functional/ui/embed_spec.lua b/test/functional/ui/embed_spec.lua
index 4fc93c3b63..10dbc68672 100644
--- a/test/functional/ui/embed_spec.lua
+++ b/test/functional/ui/embed_spec.lua
@@ -17,6 +17,7 @@ local function test_embed(ext_linegrid)
       [1] = {foreground = Screen.colors.Grey100, background = Screen.colors.Red},
       [2] = {bold = true, foreground = Screen.colors.SeaGreen4},
       [3] = {bold = true, foreground = Screen.colors.Blue1},
+      [4] = {bold = true, foreground = Screen.colors.Green},
     })
   end
 
@@ -27,9 +28,9 @@ local function test_embed(ext_linegrid)
                                                                   |
                                                                   |
                                                                   |
+                                                                  |
       Error detected while processing pre-vimrc command line:     |
       E121: Undefined variable: invalid                           |
-      E15: Invalid expression: invalid+                           |
       Press ENTER or type command to continue^                     |
     ]])
 
@@ -56,7 +57,7 @@ local function test_embed(ext_linegrid)
       Error detected while processing pre-vimrc command line:     |
       foo                                                         |
       {1:bar}                                                         |
-      {2:Press ENTER or type command to continue}^                     |
+      {4:Press ENTER or type command to continue}^                     |
     ]])
   end)
 
diff --git a/test/functional/ui/highlight_spec.lua b/test/functional/ui/highlight_spec.lua
index 55fc343e4c..96f6b43320 100644
--- a/test/functional/ui/highlight_spec.lua
+++ b/test/functional/ui/highlight_spec.lua
@@ -768,6 +768,40 @@ describe('CursorLine highlight', function()
       {4:[No Name] [+]             }{9:[No Name] [+]           }|
                                                         |
     ]])
+
+    -- CursorLine with fg=NONE is "low-priority".
+    -- Rendered as underline in a diff-line. #9028
+    command('hi CursorLine ctermbg=red ctermfg=NONE guibg=red guifg=NONE')
+    feed('kkkk')
+    screen:expect([[
+      {1:  }line 1 some text       {4:│}{1:  }line 1 some text      |
+      {1:  }{11:line 2 mo}{12:Re text!}{11:      }{4:│}{1:  }{11:^line 2 mo}{12:re text}{11:      }|
+      {1:  }{5:extra line!            }{4:│}{1:  }{6:----------------------}|
+      {1:  }extra line!            {4:│}{1:  }extra line!           |
+      {1:  }extra line!            {4:│}{1:  }extra line!           |
+      {1:  }last line ...          {4:│}{1:  }last line ...         |
+      {1:  }                       {4:│}{1:  }                      |
+      {1:  }{8:~                      }{4:│}{1:  }{8:~                     }|
+      {1:  }{8:~                      }{4:│}{1:  }{8:~                     }|
+      {1:  }{8:~                      }{4:│}{1:  }{8:~                     }|
+      {4:[No Name] [+]             }{9:[No Name] [+]           }|
+                                                        |
+    ]], {
+      [1] = {foreground = Screen.colors.DarkBlue, background = Screen.colors.WebGray},
+      [2] = {bold = true, background = Screen.colors.Red},
+      [3] = {background = Screen.colors.LightMagenta},
+      [4] = {reverse = true},
+      [5] = {background = Screen.colors.LightBlue},
+      [6] = {background = Screen.colors.LightCyan1, bold = true, foreground = Screen.colors.Blue1},
+      [7] = {foreground = Screen.colors.Grey100, background = Screen.colors.Red},
+      [8] = {bold = true, foreground = Screen.colors.Blue1},
+      [9] = {bold = true, reverse = true},
+      [10] = {bold = true},
+      [11] = {underline = true,
+              background = Screen.colors.LightMagenta},
+      [12] = {bold = true, underline = true,
+              background = Screen.colors.Red},
+    })
   end)
 end)
 
diff --git a/test/functional/ui/hlstate_spec.lua b/test/functional/ui/hlstate_spec.lua
index 672af5fb22..775b701438 100644
--- a/test/functional/ui/hlstate_spec.lua
+++ b/test/functional/ui/hlstate_spec.lua
@@ -177,11 +177,11 @@ describe('ext_hlstate detailed highlights', function()
   it("work with :terminal", function()
     screen:set_default_attr_ids({
       [1] = {{}, {{hi_name = "TermCursorNC", ui_name = "TermCursorNC", kind = "ui"}}},
-      [2] = {{special = Screen.colors.Grey0, foreground = 52479}, {{kind = "term"}}},
-      [3] = {{special = Screen.colors.Grey0, bold = true, foreground = 52479}, {{kind = "term"}}},
-      [4] = {{special = Screen.colors.Grey0, foreground = 52479}, {2, 1}},
-      [5] = {{special = Screen.colors.Grey0, foreground = 4259839}, {{kind = "term"}}},
-      [6] = {{special = Screen.colors.Grey0, foreground = 4259839}, {5, 1}},
+      [2] = {{foreground = 52479}, {{kind = "term"}}},
+      [3] = {{bold = true, foreground = 52479}, {{kind = "term"}}},
+      [4] = {{foreground = 52479}, {2, 1}},
+      [5] = {{foreground = 4259839}, {{kind = "term"}}},
+      [6] = {{foreground = 4259839}, {5, 1}},
     })
     command('enew | call termopen(["'..nvim_dir..'/tty-test"])')
     screen:expect([[
diff --git a/test/functional/ui/inccommand_spec.lua b/test/functional/ui/inccommand_spec.lua
index 736a314426..bb6cb543ed 100644
--- a/test/functional/ui/inccommand_spec.lua
+++ b/test/functional/ui/inccommand_spec.lua
@@ -2512,7 +2512,7 @@ describe(":substitute", function()
 end)
 
 it(':substitute with inccommand during :terminal activity', function()
-  retry(2, nil, function()
+  retry(2, 40000, function()
     local screen = Screen.new(30,15)
     clear()
 
diff --git a/test/functional/ui/options_spec.lua b/test/functional/ui/options_spec.lua
index 99aae16183..32e8faf7d3 100644
--- a/test/functional/ui/options_spec.lua
+++ b/test/functional/ui/options_spec.lua
@@ -1,85 +1,85 @@
+local global_helpers = require('test.helpers')
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 local clear = helpers.clear
 local command = helpers.command
 local eq = helpers.eq
+local shallowcopy = global_helpers.shallowcopy
 
 describe('ui receives option updates', function()
   local screen
 
-  before_each(function()
-    clear()
+  local function reset(opts, ...)
+    local defaults = {
+      ambiwidth='single',
+      arabicshape=true,
+      emoji=true,
+      guifont='',
+      guifontset='',
+      guifontwide='',
+      linespace=0,
+      showtabline=1,
+      termguicolors=false,
+      ext_cmdline=false,
+      ext_popupmenu=false,
+      ext_tabline=false,
+      ext_wildmenu=false,
+      ext_linegrid=false,
+      ext_hlstate=false,
+    }
+
+    clear(...)
     screen = Screen.new(20,5)
-  end)
+    screen:attach(opts)
+    -- NB: UI test suite can be run in both "linegrid" and legacy grid mode.
+    -- In both cases check that the received value is the one requested.
+    defaults.ext_linegrid = screen._options.ext_linegrid or false
+    return defaults
+  end
 
   after_each(function()
     screen:detach()
   end)
 
-  local defaults = {
-    ambiwidth='single',
-    arabicshape=true,
-    emoji=true,
-    guifont='',
-    guifontset='',
-    guifontwide='',
-    linespace=0,
-    showtabline=1,
-    termguicolors=false,
-    ext_cmdline=false,
-    ext_popupmenu=false,
-    ext_tabline=false,
-    ext_wildmenu=false,
-    ext_linegrid=false,
-    ext_hlstate=false,
-  }
-
   it("for defaults", function()
-    screen:attach()
-    -- NB: UI test suite can be run in both "linegrid" and legacy grid mode.
-    -- In both cases check that the received value is the one requested.
-    defaults.ext_linegrid = screen._options.ext_linegrid or false
+    local expected = reset()
     screen:expect(function()
-      eq(defaults, screen.options)
+      eq(expected, screen.options)
     end)
   end)
 
   it("when setting options", function()
-    screen:attach()
-    defaults.ext_linegrid = screen._options.ext_linegrid or false
-    local changed = {}
-    for k,v in pairs(defaults) do
-      changed[k] = v
-    end
+    local expected = reset()
+    local defaults = shallowcopy(expected)
 
     command("set termguicolors")
-    changed.termguicolors = true
+    expected.termguicolors = true
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     command("set guifont=Comic\\ Sans")
-    changed.guifont = "Comic Sans"
+    expected.guifont = "Comic Sans"
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     command("set showtabline=0")
-    changed.showtabline = 0
+    expected.showtabline = 0
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     command("set linespace=13")
-    changed.linespace = 13
+    expected.linespace = 13
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     command("set linespace=-11")
-    changed.linespace = -11
+    expected.linespace = -11
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     command("set all&")
@@ -89,29 +89,35 @@ describe('ui receives option updates', function()
   end)
 
   it('with UI extensions', function()
-    local changed = {}
-    for k,v in pairs(defaults) do
-      changed[k] = v
-    end
+    local expected = reset({ext_cmdline=true, ext_wildmenu=true})
 
-    screen:attach({ext_cmdline=true, ext_wildmenu=true})
-    defaults.ext_linegrid = screen._options.ext_linegrid or false
-    changed.ext_cmdline = true
-    changed.ext_wildmenu = true
+    expected.ext_cmdline = true
+    expected.ext_wildmenu = true
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     screen:set_option('ext_popupmenu', true)
-    changed.ext_popupmenu = true
+    expected.ext_popupmenu = true
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
 
     screen:set_option('ext_wildmenu', false)
-    changed.ext_wildmenu = false
+    expected.ext_wildmenu = false
     screen:expect(function()
-      eq(changed, screen.options)
+      eq(expected, screen.options)
     end)
   end)
+
+  local function startup_test(headless)
+    local expected = reset(nil,{headless=headless,args={'--cmd', 'set guifont=Comic\\ Sans\\ 12'}})
+    expected.guifont = "Comic Sans 12"
+    screen:expect(function()
+      eq(expected, screen.options)
+    end)
+  end
+
+  it('from startup options with --headless', function() startup_test(true) end)
+  it('from startup options with --embed', function() startup_test(false) end)
 end)
diff --git a/test/functional/ui/output_spec.lua b/test/functional/ui/output_spec.lua
index 1850d436ac..aa99499ec6 100644
--- a/test/functional/ui/output_spec.lua
+++ b/test/functional/ui/output_spec.lua
@@ -68,7 +68,12 @@ describe("shell command :!", function()
                                                         |
       {10:Press ENTER or type command to continue}{1: }          |
       {3:-- TERMINAL --}                                    |
-    ]])
+    ]], {
+      -- test/functional/helpers.lua defaults to background=light.
+      [1] = {reverse = true},
+      [3] = {bold = true},
+      [10] = {foreground = 2},
+    })
   end)
 end)
 
diff --git a/test/functional/ui/screen.lua b/test/functional/ui/screen.lua
index af036913d8..75eb5bb4e3 100644
--- a/test/functional/ui/screen.lua
+++ b/test/functional/ui/screen.lua
@@ -72,6 +72,7 @@
 -- To debug screen tests, see Screen:redraw_debug().
 
 local global_helpers = require('test.helpers')
+local deepcopy = global_helpers.deepcopy
 local shallowcopy = global_helpers.shallowcopy
 local helpers = require('test.functional.helpers')(nil)
 local request, run, uimeths = helpers.request, helpers.run, helpers.uimeths
@@ -176,6 +177,10 @@ function Screen:set_default_attr_ids(attr_ids)
   self._default_attr_ids = attr_ids
 end
 
+function Screen:get_default_attr_ids()
+  return deepcopy(self._default_attr_ids)
+end
+
 function Screen:set_default_attr_ignore(attr_ignore)
   self._default_attr_ignore = attr_ignore
 end
@@ -489,7 +494,7 @@ function Screen:_wait(check, flags)
   if warn_immediate and immediate_seen then
      print([[
 
-Warning: A screen test has immediate success. Try to avoid this unless the
+warning: Screen test succeeded immediately. Try to avoid this unless the
 purpose of the test really requires it.]])
     if intermediate_seen then
       print([[
@@ -498,8 +503,7 @@ Use screen:snapshot_util() or screen:redraw_debug() to find them, and add them
 to the test if they make sense.
 ]])
     else
-      print([[If necessary, silence this warning by
-supplying the 'unchanged' argument to screen:expect.]])
+      print([[If necessary, silence this warning with 'unchanged' argument of screen:expect.]])
     end
     did_warn = true
   end
@@ -507,19 +511,17 @@ supplying the 'unchanged' argument to screen:expect.]])
   if failure_after_success then
     print([[
 
-Warning: Screen changes were received after the expected state. This indicates
+warning: Screen changes were received after the expected state. This indicates
 indeterminism in the test. Try adding screen:expect(...) (or wait()) between
 asynchronous (feed(), nvim_input()) and synchronous API calls.
-  - Use Screen:redraw_debug() to investigate the problem. It might find
-    relevant intermediate states that should be added to the test to make it
-    more robust.
-  - If the point of the test is to assert the state after some user input
-    sent with feed(...), also adding an screen:expect(...) before the feed(...)
-    will help ensure the input is sent to nvim when nvim is in a predictable
-    state. This is preferable to using wait(), as it is more closely emulates
-    real user interaction.
+  - Use screen:redraw_debug() to investigate; it may find relevant intermediate
+    states that should be added to the test to make it more robust.
+  - If the purpose of the test is to assert state after some user input sent
+    with feed(), adding screen:expect() before the feed() will help to ensure
+    the input is sent when Nvim is in a predictable state. This is preferable
+    to wait(), for being closer to real user interaction.
   - wait() can trigger redraws and consequently generate more indeterminism.
-    In that case try removing every wait().
+    Try removing wait().
       ]])
     did_warn = true
   end
diff --git a/test/functional/ui/screen_basic_spec.lua b/test/functional/ui/screen_basic_spec.lua
index 1a8b7d543a..04d532f6e1 100644
--- a/test/functional/ui/screen_basic_spec.lua
+++ b/test/functional/ui/screen_basic_spec.lua
@@ -156,6 +156,82 @@ local function screen_tests(linegrid)
     end)
   end)
 
+  describe('statusline', function()
+    it('is redrawn after <c-l>', function()
+      command('set laststatus=2')
+      screen:expect([[
+        ^                                                     |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {1:[No Name]                                            }|
+                                                             |
+      ]])
+
+      feed('<c-l>')
+      screen:expect{grid=[[
+        ^                                                     |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {1:[No Name]                                            }|
+                                                             |
+      ]], reset=true}
+
+      command('split')
+      screen:expect([[
+        ^                                                     |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {1:[No Name]                                            }|
+                                                             |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {3:[No Name]                                            }|
+                                                             |
+      ]])
+
+      feed('<c-l>')
+      screen:expect{grid=[[
+        ^                                                     |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {1:[No Name]                                            }|
+                                                             |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {3:[No Name]                                            }|
+                                                             |
+      ]], reset=true}
+    end)
+  end)
+
   describe('window', function()
     describe('split', function()
       it('horizontal', function()
diff --git a/test/functional/ui/sign_spec.lua b/test/functional/ui/sign_spec.lua
index 6abeb0b2f4..bc0e2e3799 100644
--- a/test/functional/ui/sign_spec.lua
+++ b/test/functional/ui/sign_spec.lua
@@ -20,6 +20,9 @@ describe('Signs', function()
       [6] = {foreground = Screen.colors.Brown},
       [7] = {foreground = Screen.colors.DarkBlue, background = Screen.colors.LightGrey},
       [8] = {foreground = Screen.colors.Grey100, background = Screen.colors.Red},
+      [9] = {bold = true, foreground = Screen.colors.Magenta},
+      [10] = {foreground = Screen.colors.Blue1},
+      [11] = {bold = true, foreground = Screen.colors.SeaGreen4},
     } )
   end)
 
@@ -111,5 +114,45 @@ describe('Signs', function()
                                                              |
       ]])
     end)
+
+    it('can have 32bit sign IDs', function()
+      command('sign define piet text=>> texthl=Search')
+      command('sign place 100000 line=1 name=piet buffer=1')
+      feed(':sign place<cr>')
+      screen:expect([[
+        {1:>>}                                                   |
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {4:                                                     }|
+        :sign place                                          |
+        {9:--- Signs ---}                                        |
+        {10:Signs for [NULL]:}                                    |
+            line=1  id=100000  name=piet                     |
+                                                             |
+        {11:Press ENTER or type command to continue}^              |
+      ]])
+
+      feed('<cr>')
+      screen:expect([[
+        {1:>>}^                                                   |
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+        {2:  }{0:~                                                  }|
+                                                             |
+      ]])
+    end)
   end)
 end)
diff --git a/test/functional/viml/lang_spec.lua b/test/functional/viml/lang_spec.lua
index 3ba9221aef..6d603b8822 100644
--- a/test/functional/viml/lang_spec.lua
+++ b/test/functional/viml/lang_spec.lua
@@ -18,4 +18,13 @@ describe('viml', function()
     ]])
     eq(nil, string.find(eval('v:errmsg'), '^E129'))
   end)
+
+  it('str2float is not affected by locale', function()
+    if exc_exec('lang ctype sv_SE.UTF-8') ~= 0 then
+      pending("Locale sv_SE.UTF-8 not supported")
+      return
+    end
+    clear{env={LANG="", LC_NUMERIC="sv_SE.UTF-8"}}
+    eq(2.2, eval('str2float("2.2")'))
+  end)
 end)
diff --git a/test/unit/mbyte_spec.lua b/test/unit/mbyte_spec.lua
index 1e7e9fd6e6..3e65537270 100644
--- a/test/unit/mbyte_spec.lua
+++ b/test/unit/mbyte_spec.lua
@@ -43,15 +43,17 @@ describe('mbyte', function()
     -- Sequences with more than four bytes
   end)
 
-  itp('utf_char2bytes', function()
-    local char_p = ffi.typeof('char[?]')
-    for c = 0, 0xFFFF do
-      local p = char_p(4, 0)
-      mbyte.utf_char2bytes(c, p)
-      eq(c, mbyte.utf_ptr2char(p))
-      eq(charset.vim_iswordc(c), charset.vim_iswordp(p))
-    end
-  end)
+  for n = 0, 0xF do
+    itp(('utf_char2bytes for chars 0x%x - 0x%x'):format(n * 0x1000, n * 0x1000 + 0xFFF), function()
+      local char_p = ffi.typeof('char[?]')
+      for c = n * 0x1000, n * 0x1000 + 0xFFF do
+        local p = char_p(4, 0)
+        mbyte.utf_char2bytes(c, p)
+        eq(c, mbyte.utf_ptr2char(p))
+        eq(charset.vim_iswordc(c), charset.vim_iswordp(p))
+      end
+    end)
+  end
 
   describe('utfc_ptr2char_len', function()