Merge branch 'master' into option-fixes

6 files changed, 225 insertions, 75 deletions

diff --git a/test/unit/eval/typval_spec.lua b/test/unit/eval/typval_spec.lua
index 6308ae7367..5d543f914f 100644
--- a/test/unit/eval/typval_spec.lua
+++ b/test/unit/eval/typval_spec.lua
@@ -1751,6 +1751,55 @@ describe('typval.c', function()
           eq('2', s)
         end)
       end)
+      describe('get_string_buf_chk()', function()
+        local function tv_dict_get_string_buf_chk(d, key, len, buf, def, emsg)
+          buf = buf or ffi.gc(lib.xmalloc(lib.NUMBUFLEN), lib.xfree)
+          def = def or ffi.gc(lib.xstrdup('DEFAULT'), lib.xfree)
+          len = len or #key
+          alloc_log:clear()
+          local ret = check_emsg(function() return lib.tv_dict_get_string_buf_chk(d, key, len, buf, def) end,
+                                 emsg)
+          local s_ret = (ret ~= nil) and ffi.string(ret) or nil
+          if not emsg then
+            alloc_log:check({})
+          end
+          return s_ret, ret, buf, def
+        end
+        itp('works with NULL dict', function()
+          eq('DEFAULT', tv_dict_get_string_buf_chk(nil, 'test'))
+        end)
+        itp('works', function()
+          local lua_d = {
+            ['']={},
+            t=1,
+            te=int(2),
+            tes=empty_list,
+            test='tset',
+            testt=5,
+          }
+          local d = dict(lua_d)
+          alloc_log:clear()
+          eq(lua_d, dct2tbl(d))
+          alloc_log:check({})
+          local s, r, b, def
+          s, r, b, def = tv_dict_get_string_buf_chk(d, 'test')
+          neq(r, b)
+          neq(r, def)
+          eq('tset', s)
+          s, r, b, def = tv_dict_get_string_buf_chk(d, 'test', 1, nil, nil, 'E806: using Float as a String')
+          neq(r, b)
+          neq(r, def)
+          eq(nil, s)
+          s, r, b, def = tv_dict_get_string_buf_chk(d, 'te')
+          eq(r, b)
+          neq(r, def)
+          eq('2', s)
+          s, r, b, def = tv_dict_get_string_buf_chk(d, 'TEST')
+          eq(r, def)
+          neq(r, b)
+          eq('DEFAULT', s)
+        end)
+      end)
       describe('get_callback()', function()
         local function tv_dict_get_callback(d, key, key_len, emsg)
           key_len = key_len or #key
diff --git a/test/unit/os/env_spec.lua b/test/unit/os/env_spec.lua
index 575787a25e..cefd0315b7 100644
--- a/test/unit/os/env_spec.lua
+++ b/test/unit/os/env_spec.lua
@@ -13,7 +13,7 @@ require('lfs')
 
 local cimp = cimport('./src/nvim/os/os.h')
 
-describe('env function', function()
+describe('env.c', function()
   local function os_setenv(name, value, override)
     return cimp.os_setenv(to_cstr(name), to_cstr(value), override)
   end
diff --git a/test/unit/os/fs_spec.lua b/test/unit/os/fs_spec.lua
index 860ebfdbcb..23eb05b4b8 100644
--- a/test/unit/os/fs_spec.lua
+++ b/test/unit/os/fs_spec.lua
@@ -35,7 +35,6 @@ for i = 0, 255 do
 end
 local fcontents = s:rep(16)
 
-local buffer = ""
 local directory = nil
 local absolute_executable = nil
 local executable_name = nil
@@ -65,7 +64,11 @@ local function os_getperm(filename)
   return tonumber(perm)
 end
 
-describe('fs function', function()
+describe('fs.c', function()
+  local function os_isdir(name)
+    return fs.os_isdir(to_cstr(name))
+  end
+
   before_each(function()
     lfs.mkdir('unit-test-directory');
 
@@ -91,32 +94,37 @@ describe('fs function', function()
   end)
 
   describe('os_dirname', function()
-    local length
-
-    local function os_dirname(buf, len)
-      return fs.os_dirname(buf, len)
-    end
-
-    before_each(function()
-      length = (string.len(lfs.currentdir())) + 1
-      buffer = cstr(length, '')
+    itp('returns OK and writes current directory to the buffer', function()
+      local length = string.len(lfs.currentdir()) + 1
+      local buf = cstr(length, '')
+      eq(OK, fs.os_dirname(buf, length))
+      eq(lfs.currentdir(), ffi.string(buf))
     end)
 
-    itp('returns OK and writes current directory into the buffer if it is large\n    enough', function()
-      eq(OK, (os_dirname(buffer, length)))
-      eq(lfs.currentdir(), (ffi.string(buffer)))
-    end)
-
-    -- What kind of other failing cases are possible?
     itp('returns FAIL if the buffer is too small', function()
-      local buf = cstr((length - 1), '')
-      eq(FAIL, (os_dirname(buf, (length - 1))))
+      local length = string.len(lfs.currentdir()) + 1
+      local buf = cstr(length - 1, '')
+      eq(FAIL, fs.os_dirname(buf, length - 1))
     end)
   end)
 
-  local function os_isdir(name)
-    return fs.os_isdir((to_cstr(name)))
-  end
+  describe('os_chdir', function()
+    itp('fails with path="~"', function()
+      eq(false, os_isdir('~')) -- sanity check: no literal "~" directory.
+      local length = 4096
+      local expected_cwd = cstr(length, '')
+      local cwd = cstr(length, '')
+      eq(OK, fs.os_dirname(expected_cwd, length))
+
+      -- os_chdir returns 0 for success, not OK (1).
+      neq(0, fs.os_chdir('~'))    -- fail
+      neq(0, fs.os_chdir('~/'))   -- fail
+
+      eq(OK, fs.os_dirname(cwd, length))
+      -- CWD did not change.
+      eq(ffi.string(expected_cwd), ffi.string(cwd))
+    end)
+  end)
 
   describe('os_isdir', function()
     itp('returns false if an empty string is given', function()
diff --git a/test/unit/os/shell_spec.lua b/test/unit/os/shell_spec.lua
index e883301cfb..37274502de 100644
--- a/test/unit/os/shell_spec.lua
+++ b/test/unit/os/shell_spec.lua
@@ -15,7 +15,7 @@ local NULL = ffi.cast('void *', 0)
 describe('shell functions', function()
   before_each(function()
     -- os_system() can't work when the p_sh and p_shcf variables are unset
-    cimported.p_sh = to_cstr('/bin/bash')
+    cimported.p_sh = to_cstr('/bin/sh')
     cimported.p_shcf = to_cstr('-c')
     cimported.p_sxq = to_cstr('')
     cimported.p_sxe = to_cstr('')
@@ -53,14 +53,14 @@ describe('shell functions', function()
 
   describe('os_system', function()
     itp('can echo some output (shell builtin)', function()
-      local cmd, text = 'echo -n', 'some text'
+      local cmd, text = 'printf "%s "', 'some text '
       local status, output = os_system(cmd .. ' ' .. text)
       eq(text, output)
       eq(0, status)
     end)
 
     itp('can deal with empty output', function()
-      local cmd = 'echo -n'
+      local cmd = 'printf ""'
       local status, output = os_system(cmd)
       eq('', output)
       eq(0, status)
@@ -81,19 +81,19 @@ describe('shell functions', function()
 
   describe('shell_build_argv', function()
     itp('works with NULL arguments', function()
-      eq({'/bin/bash'}, shell_build_argv(nil, nil))
+      eq({'/bin/sh'}, shell_build_argv(nil, nil))
     end)
 
     itp('works with cmd', function()
-      eq({'/bin/bash', '-c', 'abc  def'}, shell_build_argv('abc  def', nil))
+      eq({'/bin/sh', '-c', 'abc  def'}, shell_build_argv('abc  def', nil))
     end)
 
     itp('works with extra_args', function()
-      eq({'/bin/bash', 'ghi  jkl'}, shell_build_argv(nil, 'ghi  jkl'))
+      eq({'/bin/sh', 'ghi  jkl'}, shell_build_argv(nil, 'ghi  jkl'))
     end)
 
     itp('works with cmd and extra_args', function()
-      eq({'/bin/bash', 'ghi  jkl', '-c', 'abc  def'}, shell_build_argv('abc  def', 'ghi  jkl'))
+      eq({'/bin/sh', 'ghi  jkl', '-c', 'abc  def'}, shell_build_argv('abc  def', 'ghi  jkl'))
     end)
 
     itp('splits and unquotes &shell and &shellcmdflag', function()
@@ -112,7 +112,7 @@ describe('shell functions', function()
 
       local argv = ffi.cast('char**',
                         cimported.shell_build_argv(to_cstr('echo &|<>()@^'), nil))
-      eq(ffi.string(argv[0]), '/bin/bash')
+      eq(ffi.string(argv[0]), '/bin/sh')
       eq(ffi.string(argv[1]), '-c')
       eq(ffi.string(argv[2]), '(echo ^&^|^<^>^(^)^@^^)')
       eq(nil, argv[3])
@@ -124,7 +124,7 @@ describe('shell functions', function()
 
       local argv = ffi.cast('char**', cimported.shell_build_argv(
                                           to_cstr('echo -n some text'), nil))
-      eq(ffi.string(argv[0]), '/bin/bash')
+      eq(ffi.string(argv[0]), '/bin/sh')
       eq(ffi.string(argv[1]), '-c')
       eq(ffi.string(argv[2]), '"(echo -n some text)"')
       eq(nil, argv[3])
@@ -136,7 +136,7 @@ describe('shell functions', function()
 
       local argv = ffi.cast('char**', cimported.shell_build_argv(
                                           to_cstr('echo -n some text'), nil))
-      eq(ffi.string(argv[0]), '/bin/bash')
+      eq(ffi.string(argv[0]), '/bin/sh')
       eq(ffi.string(argv[1]), '-c')
       eq(ffi.string(argv[2]), '"echo -n some text"')
       eq(nil, argv[3])
@@ -145,7 +145,7 @@ describe('shell functions', function()
     itp('with empty shellxquote/shellxescape', function()
       local argv = ffi.cast('char**', cimported.shell_build_argv(
                                           to_cstr('echo -n some text'), nil))
-      eq(ffi.string(argv[0]), '/bin/bash')
+      eq(ffi.string(argv[0]), '/bin/sh')
       eq(ffi.string(argv[1]), '-c')
       eq(ffi.string(argv[2]), 'echo -n some text')
       eq(nil, argv[3])
diff --git a/test/unit/path_spec.lua b/test/unit/path_spec.lua
index 470f971e68..a9cba7df84 100644
--- a/test/unit/path_spec.lua
+++ b/test/unit/path_spec.lua
@@ -13,12 +13,12 @@ local OK = helpers.OK
 local FAIL = helpers.FAIL
 
 cimport('string.h')
-local path = cimport('./src/nvim/path.h')
+local cimp = cimport('./src/nvim/os/os.h', './src/nvim/path.h')
 
 local length = 0
 local buffer = nil
 
-describe('path function', function()
+describe('path.c', function()
   describe('path_full_dir_name', function()
     setup(function()
       lfs.mkdir('unit-test-directory')
@@ -30,7 +30,7 @@ describe('path function', function()
 
     local function path_full_dir_name(directory, buf, len)
       directory = to_cstr(directory)
-      return path.path_full_dir_name(directory, buf, len)
+      return cimp.path_full_dir_name(directory, buf, len)
     end
 
     before_each(function()
@@ -69,7 +69,7 @@ describe('path function', function()
     local function path_full_compare(s1, s2, cn)
       s1 = to_cstr(s1)
       s2 = to_cstr(s2)
-      return path.path_full_compare(s1, s2, cn or 0)
+      return cimp.path_full_compare(s1, s2, cn or 0)
     end
 
     local f1 = 'f1.o'
@@ -86,31 +86,31 @@ describe('path function', function()
     end)
 
     itp('returns kEqualFiles when passed the same file', function()
-      eq(path.kEqualFiles, (path_full_compare(f1, f1)))
+      eq(cimp.kEqualFiles, (path_full_compare(f1, f1)))
     end)
 
     itp('returns kEqualFileNames when files that dont exist and have same name', function()
-      eq(path.kEqualFileNames, (path_full_compare('null.txt', 'null.txt', true)))
+      eq(cimp.kEqualFileNames, (path_full_compare('null.txt', 'null.txt', true)))
     end)
 
     itp('returns kBothFilesMissing when files that dont exist', function()
-      eq(path.kBothFilesMissing, (path_full_compare('null.txt', 'null.txt')))
+      eq(cimp.kBothFilesMissing, (path_full_compare('null.txt', 'null.txt')))
     end)
 
     itp('returns kDifferentFiles when passed different files', function()
-      eq(path.kDifferentFiles, (path_full_compare(f1, f2)))
-      eq(path.kDifferentFiles, (path_full_compare(f2, f1)))
+      eq(cimp.kDifferentFiles, (path_full_compare(f1, f2)))
+      eq(cimp.kDifferentFiles, (path_full_compare(f2, f1)))
     end)
 
     itp('returns kOneFileMissing if only one does not exist', function()
-      eq(path.kOneFileMissing, (path_full_compare(f1, 'null.txt')))
-      eq(path.kOneFileMissing, (path_full_compare('null.txt', f1)))
+      eq(cimp.kOneFileMissing, (path_full_compare(f1, 'null.txt')))
+      eq(cimp.kOneFileMissing, (path_full_compare('null.txt', f1)))
     end)
   end)
 
   describe('path_tail', function()
     local function path_tail(file)
-      local res = path.path_tail((to_cstr(file)))
+      local res = cimp.path_tail((to_cstr(file)))
       neq(NULL, res)
       return ffi.string(res)
     end
@@ -126,7 +126,7 @@ describe('path function', function()
 
   describe('path_tail_with_sep', function()
     local function path_tail_with_sep(file)
-      local res = path.path_tail_with_sep((to_cstr(file)))
+      local res = cimp.path_tail_with_sep((to_cstr(file)))
       neq(NULL, res)
       return ffi.string(res)
     end
@@ -159,11 +159,11 @@ describe('path function', function()
     -- strcmp.
     local function invocation_path_tail(invk)
       local plen = ffi.new('size_t[?]', 1)
-      local ptail = path.invocation_path_tail((to_cstr(invk)), plen)
+      local ptail = cimp.invocation_path_tail((to_cstr(invk)), plen)
       neq(NULL, ptail)
 
       -- it does not change the output if len==NULL
-      local tail2 = path.invocation_path_tail((to_cstr(invk)), NULL)
+      local tail2 = cimp.invocation_path_tail((to_cstr(invk)), NULL)
       neq(NULL, tail2)
       eq((ffi.string(ptail)), (ffi.string(tail2)))
       return ptail, plen[0]
@@ -204,7 +204,7 @@ describe('path function', function()
     end)
 
     itp('is equivalent to path_tail when args do not contain a path separator', function()
-      local ptail = path.path_tail(to_cstr("a/b/c x y z"))
+      local ptail = cimp.path_tail(to_cstr("a/b/c x y z"))
       neq(NULL, ptail)
       local tail = ffi.string(ptail)
       local invk, _ = invocation_path_tail("a/b/c x y z")
@@ -212,7 +212,7 @@ describe('path function', function()
     end)
 
     itp('is not equivalent to path_tail when args contain a path separator', function()
-      local ptail = path.path_tail(to_cstr("a/b/c x y/z"))
+      local ptail = cimp.path_tail(to_cstr("a/b/c x y/z"))
       neq(NULL, ptail)
       local invk, _ = invocation_path_tail("a/b/c x y/z")
       neq((ffi.string(ptail)), (ffi.string(invk)))
@@ -221,7 +221,7 @@ describe('path function', function()
 
   describe('path_next_component', function()
     local function path_next_component(file)
-      local res = path.path_next_component((to_cstr(file)))
+      local res = cimp.path_next_component((to_cstr(file)))
       neq(NULL, res)
       return ffi.string(res)
     end
@@ -238,25 +238,25 @@ describe('path function', function()
   describe('path_shorten_fname', function()
     itp('returns NULL if `full_path` is NULL', function()
       local dir = to_cstr('some/directory/file.txt')
-      eq(NULL, (path.path_shorten_fname(NULL, dir)))
+      eq(NULL, (cimp.path_shorten_fname(NULL, dir)))
     end)
 
     itp('returns NULL if the path and dir does not match', function()
       local dir = to_cstr('not/the/same')
       local full = to_cstr('as/this.txt')
-      eq(NULL, (path.path_shorten_fname(full, dir)))
+      eq(NULL, (cimp.path_shorten_fname(full, dir)))
     end)
 
     itp('returns NULL if the path is not separated properly', function()
       local dir = to_cstr('some/very/long/')
       local full = to_cstr('some/very/long/directory/file.txt')
-      eq(NULL, (path.path_shorten_fname(full, dir)))
+      eq(NULL, (cimp.path_shorten_fname(full, dir)))
     end)
 
     itp('shortens the filename if `dir_name` is the start of `full_path`', function()
       local full = to_cstr('some/very/long/directory/file.txt')
       local dir = to_cstr('some/very/long')
-      eq('directory/file.txt', (ffi.string(path.path_shorten_fname(full, dir))))
+      eq('directory/file.txt', (ffi.string(cimp.path_shorten_fname(full, dir))))
     end)
   end)
 end)
@@ -277,23 +277,76 @@ describe('path_shorten_fname_if_possible', function()
     itp('returns shortened path if possible', function()
       lfs.chdir('ut_directory')
       local full = to_cstr(lfs.currentdir() .. '/subdir/file.txt')
-      eq('subdir/file.txt', (ffi.string(path.path_shorten_fname_if_possible(full))))
+      eq('subdir/file.txt', (ffi.string(cimp.path_shorten_fname_if_possible(full))))
     end)
 
     itp('returns `full_path` if a shorter version is not possible', function()
       local old = lfs.currentdir()
       lfs.chdir('ut_directory')
       local full = old .. '/subdir/file.txt'
-      eq(full, (ffi.string(path.path_shorten_fname_if_possible(to_cstr(full)))))
+      eq(full, (ffi.string(cimp.path_shorten_fname_if_possible(to_cstr(full)))))
     end)
 
     itp('returns NULL if `full_path` is NULL', function()
-      eq(NULL, (path.path_shorten_fname_if_possible(NULL)))
+      eq(NULL, (cimp.path_shorten_fname_if_possible(NULL)))
     end)
   end)
 end)
 
-describe('more path function', function()
+describe('path.c path_guess_exepath', function()
+  local cwd = lfs.currentdir()
+
+  for _,name in ipairs({'./nvim', '.nvim', 'foo/nvim'}) do
+    itp('"'..name..'" returns name catenated with CWD', function()
+      local bufsize = 255
+      local buf = cstr(bufsize, '')
+      cimp.path_guess_exepath(name, buf, bufsize)
+      eq(cwd..'/'..name, ffi.string(buf))
+    end)
+  end
+
+  itp('absolute path returns the name unmodified', function()
+    local name = '/foo/bar/baz'
+    local bufsize = 255
+    local buf = cstr(bufsize, '')
+    cimp.path_guess_exepath(name, buf, bufsize)
+    eq(name, ffi.string(buf))
+  end)
+
+  itp('returns the name unmodified if not found in $PATH', function()
+    local name = '23u0293_not_in_path'
+    local bufsize = 255
+    local buf = cstr(bufsize, '')
+    cimp.path_guess_exepath(name, buf, bufsize)
+    eq(name, ffi.string(buf))
+  end)
+
+  itp('does not crash if $PATH item exceeds MAXPATHL', function()
+    local orig_path_env = os.getenv('PATH')
+    local name = 'cat'  -- Some executable in $PATH.
+    local bufsize = 255
+    local buf = cstr(bufsize, '')
+    local insane_path = orig_path_env..':'..(("x/"):rep(4097))
+
+    cimp.os_setenv('PATH', insane_path, true)
+    cimp.path_guess_exepath(name, buf, bufsize)
+    eq('bin/' .. name, ffi.string(buf):sub(-#('bin/' .. name), -1))
+
+    -- Restore $PATH.
+    cimp.os_setenv('PATH', orig_path_env, true)
+  end)
+
+  itp('returns full path found in $PATH', function()
+    local name = 'cat'  -- Some executable in $PATH.
+    local bufsize = 255
+    local buf = cstr(bufsize, '')
+    cimp.path_guess_exepath(name, buf, bufsize)
+    -- Usually "/bin/cat" on unix, "/path/to/nvim/cat" on Windows.
+    eq('bin/' .. name, ffi.string(buf):sub(-#('bin/' .. name), -1))
+  end)
+end)
+
+describe('path.c', function()
   setup(function()
     lfs.mkdir('unit-test-directory');
     io.open('unit-test-directory/test.file', 'w').close()
@@ -315,7 +368,7 @@ describe('more path function', function()
   describe('vim_FullName', function()
     local function vim_FullName(filename, buf, len, force)
       filename = to_cstr(filename)
-      return path.vim_FullName(filename, buf, len, force)
+      return cimp.vim_FullName(filename, buf, len, force)
     end
 
     before_each(function()
@@ -326,7 +379,7 @@ describe('more path function', function()
 
     itp('fails if given filename is NULL', function()
       local force_expansion = 1
-      local result = path.vim_FullName(NULL, buffer, length, force_expansion)
+      local result = cimp.vim_FullName(NULL, buffer, length, force_expansion)
       eq(FAIL, result)
     end)
 
@@ -335,7 +388,7 @@ describe('more path function', function()
       local filename = 'foo/bar/bazzzzzzz/buz/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/a'
       local too_short_len = 8
       local buf = cstr(too_short_len, '')
-      local result = path.vim_FullName(filename, buf, too_short_len, force_expansion)
+      local result = cimp.vim_FullName(filename, buf, too_short_len, force_expansion)
       local expected = string.sub(filename, 1, (too_short_len - 1))
       eq(expected, (ffi.string(buf)))
       eq(FAIL, result)
@@ -357,7 +410,7 @@ describe('more path function', function()
       eq(FAIL, result)
     end)
 
-    itp('concatenates given filename if it does not contain a slash', function()
+    itp('concatenates filename if it does not contain a slash', function()
       local force_expansion = 1
       local result = vim_FullName('test.file', buffer, length, force_expansion)
       local expected = lfs.currentdir() .. '/test.file'
@@ -365,7 +418,7 @@ describe('more path function', function()
       eq(OK, result)
     end)
 
-    itp('concatenates given filename if it is a directory but does not contain a\n    slash', function()
+    itp('concatenates directory name if it does not contain a slash', function()
       local force_expansion = 1
       local result = vim_FullName('..', buffer, length, force_expansion)
       local expected = lfs.currentdir() .. '/..'
@@ -395,6 +448,7 @@ describe('more path function', function()
     end)
 
     itp('fails and uses filename when the path is relative to HOME', function()
+      eq(false, cimp.os_isdir('~')) -- sanity check: no literal "~" directory.
       local force_expansion = 1
       local absolute_path = '~/home.file'
       local result = vim_FullName(absolute_path, buffer, length, force_expansion)
@@ -414,7 +468,7 @@ describe('more path function', function()
       local filename = to_cstr('unit-test-directory/test.file')
       -- Don't use the wrapper here but pass a cstring directly to the c
       -- function.
-      local result = path.vim_FullName(filename, buffer, length, force_expansion)
+      local result = cimp.vim_FullName(filename, buffer, length, force_expansion)
       eq(lfs.currentdir() .. '/unit-test-directory/test.file', (ffi.string(buffer)))
       eq('unit-test-directory/test.file', (ffi.string(filename)))
       eq(OK, result)
@@ -423,7 +477,7 @@ describe('more path function', function()
     itp('works with directories that have one path component', function()
       local force_expansion = 1
       local filename = to_cstr('/tmp')
-      local result = path.vim_FullName(filename, buffer, length, force_expansion)
+      local result = cimp.vim_FullName(filename, buffer, length, force_expansion)
       eq('/tmp', ffi.string(buffer))
       eq(OK, result)
     end)
@@ -432,7 +486,7 @@ describe('more path function', function()
   describe('path_fix_case', function()
     local function fix_case(file)
       local c_file = to_cstr(file)
-      path.path_fix_case(c_file)
+      cimp.path_fix_case(c_file)
       return ffi.string(c_file)
     end
 
@@ -456,41 +510,41 @@ describe('more path function', function()
     itp('joins given paths with a slash', function()
       local path1 = cstr(100, 'path1')
       local to_append = to_cstr('path2')
-      eq(OK, (path.append_path(path1, to_append, 100)))
+      eq(OK, (cimp.append_path(path1, to_append, 100)))
       eq("path1/path2", (ffi.string(path1)))
     end)
 
     itp('joins given paths without adding an unnecessary slash', function()
       local path1 = cstr(100, 'path1/')
       local to_append = to_cstr('path2')
-      eq(OK, path.append_path(path1, to_append, 100))
+      eq(OK, cimp.append_path(path1, to_append, 100))
       eq("path1/path2", (ffi.string(path1)))
     end)
 
     itp('fails and uses filename if there is not enough space left for to_append', function()
       local path1 = cstr(11, 'path1/')
       local to_append = to_cstr('path2')
-      eq(FAIL, (path.append_path(path1, to_append, 11)))
+      eq(FAIL, (cimp.append_path(path1, to_append, 11)))
     end)
 
     itp('does not append a slash if to_append is empty', function()
       local path1 = cstr(6, 'path1')
       local to_append = to_cstr('')
-      eq(OK, (path.append_path(path1, to_append, 6)))
+      eq(OK, (cimp.append_path(path1, to_append, 6)))
       eq('path1', (ffi.string(path1)))
     end)
 
     itp('does not append unnecessary dots', function()
       local path1 = cstr(6, 'path1')
       local to_append = to_cstr('.')
-      eq(OK, (path.append_path(path1, to_append, 6)))
+      eq(OK, (cimp.append_path(path1, to_append, 6)))
       eq('path1', (ffi.string(path1)))
     end)
 
     itp('copies to_append to path, if path is empty', function()
       local path1 = cstr(7, '')
       local to_append = to_cstr('/path2')
-      eq(OK, (path.append_path(path1, to_append, 7)))
+      eq(OK, (cimp.append_path(path1, to_append, 7)))
       eq('/path2', (ffi.string(path1)))
     end)
   end)
@@ -498,7 +552,7 @@ describe('more path function', function()
   describe('path_is_absolute_path', function()
     local function path_is_absolute_path(filename)
       filename = to_cstr(filename)
-      return path.path_is_absolute_path(filename)
+      return cimp.path_is_absolute_path(filename)
     end
 
     itp('returns true if filename starts with a slash', function()
diff --git a/test/unit/strings_spec.lua b/test/unit/strings_spec.lua
index 3bc3dc7130..e54c82b26a 100644
--- a/test/unit/strings_spec.lua
+++ b/test/unit/strings_spec.lua
@@ -99,3 +99,42 @@ describe('vim_strnsave_unquoted()', function()
     eq('/Program\\nFiles/sh', vim_strnsave_unquoted('/Program"\\n"Files/sh'))
   end)
 end)
+
+describe('vim_strchr()', function()
+  local vim_strchr = function(s, c)
+    local str = to_cstr(s)
+    local res = strings.vim_strchr(str, c)
+    if res == nil then
+      return nil
+    else
+      return res - str
+    end
+  end
+  itp('handles NUL and <0 correctly', function()
+    eq(nil, vim_strchr('abc', 0))
+    eq(nil, vim_strchr('abc', -1))
+  end)
+  itp('works', function()
+    eq(0, vim_strchr('abc', ('a'):byte()))
+    eq(1, vim_strchr('abc', ('b'):byte()))
+    eq(2, vim_strchr('abc', ('c'):byte()))
+    eq(0, vim_strchr('a«b»c', ('a'):byte()))
+    eq(3, vim_strchr('a«b»c', ('b'):byte()))
+    eq(6, vim_strchr('a«b»c', ('c'):byte()))
+
+    eq(nil, vim_strchr('«»', ('«'):byte()))
+    -- 0xAB == 171 == '«'
+    eq(nil, vim_strchr('\171', 0xAB))
+    eq(0, vim_strchr('«»', 0xAB))
+    eq(3, vim_strchr('„«»“', 0xAB))
+
+    eq(7, vim_strchr('„«»“', 0x201C))
+    eq(nil, vim_strchr('„«»“', 0x201D))
+    eq(0, vim_strchr('„«»“', 0x201E))
+
+    eq(0, vim_strchr('\244\143\188\128', 0x10FF00))
+    eq(2, vim_strchr('«\244\143\188\128»', 0x10FF00))
+    --                   |0xDBFF     |0xDF00  - surrogate pair for 0x10FF00
+    eq(nil, vim_strchr('«\237\175\191\237\188\128»', 0x10FF00))
+  end)
+end)