test/old: restore test_backspace_opt.vim

Porting it to test/functional/legacy/backspace_opt_spec.lua
was a mistake.
Tests pass after commenting out some lines for Vi compatibility.

File is copied from Vim as of patch v8.2.0540.
Patch v8.2.0540 cannot be fully ported yet.
This file is a prequisite for future v8.2.x patches.

2 files changed, 110 insertions, 67 deletions

diff --git a/src/nvim/testdir/test_backspace_opt.vim b/src/nvim/testdir/test_backspace_opt.vim
new file mode 100644
index 0000000000..cfae88dabd
--- /dev/null
+++ b/src/nvim/testdir/test_backspace_opt.vim
@@ -0,0 +1,110 @@
+" Tests for 'backspace' settings
+
+func Exec(expr)
+  let str=''
+  try
+    exec a:expr
+  catch /.*/
+    let str=v:exception
+  endtry
+  return str
+endfunc
+
+func Test_backspace_option()
+  set backspace=
+  call assert_equal('', &backspace)
+  set backspace=indent
+  call assert_equal('indent', &backspace)
+  set backspace=eol
+  call assert_equal('eol', &backspace)
+  set backspace=start
+  call assert_equal('start', &backspace)
+  " Add the value
+  set backspace=
+  set backspace=indent
+  call assert_equal('indent', &backspace)
+  set backspace+=eol
+  call assert_equal('indent,eol', &backspace)
+  set backspace+=start
+  call assert_equal('indent,eol,start', &backspace)
+  " Delete the value
+  set backspace-=indent
+  call assert_equal('eol,start', &backspace)
+  set backspace-=start
+  call assert_equal('eol', &backspace)
+  set backspace-=eol
+  call assert_equal('', &backspace)
+  " Check the error
+  call assert_equal(0, match(Exec('set backspace=ABC'), '.*E474'))
+  call assert_equal(0, match(Exec('set backspace+=def'), '.*E474'))
+  " NOTE: Vim doesn't check following error...
+  "call assert_equal(0, match(Exec('set backspace-=ghi'), '.*E474'))
+
+  " Check backwards compatibility with version 5.4 and earlier
+  set backspace=0
+  call assert_equal('0', &backspace)
+  set backspace=1
+  call assert_equal('1', &backspace)
+  set backspace=2
+  call assert_equal('2', &backspace)
+  call assert_false(match(Exec('set backspace=3'), '.*E474'))
+  call assert_false(match(Exec('set backspace=10'), '.*E474'))
+
+  " Cleared when 'compatible' is set
+  " set compatible
+  " call assert_equal('', &backspace)
+  set nocompatible viminfo+=nviminfo
+endfunc
+
+" Test with backspace set to the non-compatible setting
+func Test_backspace_ctrl_u()
+  new
+  call append(0,  [
+        \ "1 this shouldn't be deleted",
+        \ "2 this shouldn't be deleted",
+        \ "3 this shouldn't be deleted",
+        \ "4 this should be deleted",
+        \ "5 this shouldn't be deleted",
+        \ "6 this shouldn't be deleted",
+        \ "7 this shouldn't be deleted",
+        \ "8 this shouldn't be deleted (not touched yet)"])
+  call cursor(2, 1)
+
+  " set compatible
+  set backspace=2
+
+  exe "normal Avim1\<C-U>\<Esc>\<CR>"
+  exe "normal Avim2\<C-G>u\<C-U>\<Esc>\<CR>"
+
+  set cpo-=<
+  inoremap <c-u> <left><c-u>
+  exe "normal Avim3\<C-U>\<Esc>\<CR>"
+  iunmap <c-u>
+  exe "normal Avim4\<C-U>\<C-U>\<Esc>\<CR>"
+
+  " Test with backspace set to the compatible setting
+  set backspace= visualbell
+  exe "normal A vim5\<Esc>A\<C-U>\<C-U>\<Esc>\<CR>"
+  exe "normal A vim6\<Esc>Azwei\<C-G>u\<C-U>\<Esc>\<CR>"
+
+  inoremap <c-u> <left><c-u>
+  exe "normal A vim7\<C-U>\<C-U>\<Esc>\<CR>"
+
+  call assert_equal([
+        \ "1 this shouldn't be deleted",
+        \ "2 this shouldn't be deleted",
+        \ "3 this shouldn't be deleted",
+        \ "4 this should be deleted3",
+        \ "",
+        \ "6 this shouldn't be deleted vim5",
+        \ "7 this shouldn't be deleted vim6",
+        \ "8 this shouldn't be deleted (not touched yet) vim7",
+        \ ""], getline(1, '$'))
+
+  set compatible&vim
+  set visualbell&vim
+  set backspace&vim
+  close!
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab
diff --git a/test/functional/legacy/backspace_opt_spec.lua b/test/functional/legacy/backspace_opt_spec.lua
deleted file mode 100644
index 90bc6f74f0..0000000000
--- a/test/functional/legacy/backspace_opt_spec.lua
+++ /dev/null
@@ -1,67 +0,0 @@
-local helpers = require('test.functional.helpers')(after_each)
-local call, clear = helpers.call, helpers.clear
-local source, eq, nvim = helpers.source, helpers.eq, helpers.meths
-
-describe("test 'backspace' settings", function()
-  before_each(function()
-    clear()
-
-    source([[
-      func Exec(expr)
-        let str=''
-        try
-          exec a:expr
-        catch /.*/
-          let str=v:exception
-        endtry
-        return str
-      endfunc
-
-      func Test_backspace_option()
-        set backspace=
-        call assert_equal('', &backspace)
-        set backspace=indent
-        call assert_equal('indent', &backspace)
-        set backspace=eol
-        call assert_equal('eol', &backspace)
-        set backspace=start
-        call assert_equal('start', &backspace)
-        " Add the value
-        set backspace=
-        set backspace=indent
-        call assert_equal('indent', &backspace)
-        set backspace+=eol
-        call assert_equal('indent,eol', &backspace)
-        set backspace+=start
-        call assert_equal('indent,eol,start', &backspace)
-        " Delete the value
-        set backspace-=indent
-        call assert_equal('eol,start', &backspace)
-        set backspace-=start
-        call assert_equal('eol', &backspace)
-        set backspace-=eol
-        call assert_equal('', &backspace)
-        " Check the error
-        call assert_equal(0, match(Exec('set backspace=ABC'), '.*E474'))
-        call assert_equal(0, match(Exec('set backspace+=def'), '.*E474'))
-        " NOTE: Vim doesn't check following error...
-        "call assert_equal(0, match(Exec('set backspace-=ghi'), '.*E474'))
-
-        " Check backwards compatibility with version 5.4 and earlier
-        set backspace=0
-        call assert_equal('0', &backspace)
-        set backspace=1
-        call assert_equal('1', &backspace)
-        set backspace=2
-        call assert_equal('2', &backspace)
-        call assert_false(match(Exec('set backspace=3'), '.*E474'))
-        call assert_false(match(Exec('set backspace=10'), '.*E474'))
-      endfunc
-    ]])
-  end)
-
-  it('works', function()
-    call('Test_backspace_option')
-    eq({}, nvim.get_vvar('errors'))
-  end)
-end)