Merge #9709 'fileio: use os_copy to create backups'

ref #8288

3 files changed, 29 insertions, 4 deletions

diff --git a/test/functional/core/fileio_spec.lua b/test/functional/core/fileio_spec.lua
index 09533e4e60..c74eb3bb02 100644
--- a/test/functional/core/fileio_spec.lua
+++ b/test/functional/core/fileio_spec.lua
@@ -10,6 +10,8 @@ local request = helpers.request
 local retry = helpers.retry
 local rmdir = helpers.rmdir
 local sleep = helpers.sleep
+local read_file = helpers.read_file
+local trim = helpers.trim
 
 describe('fileio', function()
   before_each(function()
@@ -18,6 +20,7 @@ describe('fileio', function()
     command(':qall!')
     os.remove('Xtest_startup_shada')
     os.remove('Xtest_startup_file1')
+    os.remove('Xtest_startup_file1~')
     os.remove('Xtest_startup_file2')
     rmdir('Xtest_startup_swapdir')
   end)
@@ -64,5 +67,25 @@ describe('fileio', function()
     command('write')
     eq(4, request('nvim__stats').fsync)
   end)
+
+  it('backup #9709', function()
+    clear({ args={ '-i', 'Xtest_startup_shada',
+                   '--cmd', 'set directory=Xtest_startup_swapdir' } })
+
+    command('write Xtest_startup_file1')
+    feed('ifoo<esc>')
+    command('set backup')
+    command('set backupcopy=yes')
+    command('write')
+    feed('Abar<esc>')
+    command('write')
+
+    local foobar_contents = trim(read_file('Xtest_startup_file1'))
+    local bar_contents = trim(read_file('Xtest_startup_file1~'))
+
+    eq('foobar', foobar_contents);
+    eq('foo', bar_contents);
+
+  end)
 end)
 
diff --git a/test/helpers.lua b/test/helpers.lua
index 3311f3ef97..2a6285e685 100644
--- a/test/helpers.lua
+++ b/test/helpers.lua
@@ -697,6 +697,10 @@ local function read_nvim_log()
   return log
 end
 
+local function trim(s)
+  return s:match('^%s*(.*%S)') or ''
+end
+
 local module = {
   REMOVE_THIS = REMOVE_THIS,
   argss_to_cmd = argss_to_cmd,
@@ -736,6 +740,7 @@ local module = {
   updated = updated,
   which = which,
   write_file = write_file,
+  trim = trim,
 }
 module = shared.tbl_extend('error', module, Paths, shared)
 
diff --git a/test/unit/helpers.lua b/test/unit/helpers.lua
index e634b7296e..b5d3dd9f47 100644
--- a/test/unit/helpers.lua
+++ b/test/unit/helpers.lua
@@ -15,6 +15,7 @@ local dedent = global_helpers.dedent
 local neq = global_helpers.neq
 local map = global_helpers.map
 local eq = global_helpers.eq
+local trim = global_helpers.trim
 
 -- C constants.
 local NULL = ffi.cast('void*', 0)
@@ -119,10 +120,6 @@ local deinit = only_separate(function()
   end
 end)
 
-local function trim(s)
-  return s:match('^%s*(.*%S)') or ''
-end
-
 -- a Set that keeps around the lines we've already seen
 local cdefs_init = Set:new()
 local cdefs_mod = nil