new file mode 100644
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+++ b/src/testdir/test_cmdwin.vim
@@ -0,0 +1,360 @@
+" Tests for editing the command line.
+
+source check.vim
+CheckFeature cmdwin
+
+source screendump.vim
+
+func Test_getcmdwintype()
+  call feedkeys("q/:let a = getcmdwintype()\<CR>:q\<CR>", 'x!')
+  call assert_equal('/', a)
+
+  call feedkeys("q?:let a = getcmdwintype()\<CR>:q\<CR>", 'x!')
+  call assert_equal('?', a)
+
+  call feedkeys("q::let a = getcmdwintype()\<CR>:q\<CR>", 'x!')
+  call assert_equal(':', a)
+
+  call feedkeys(":\<C-F>:let a = getcmdwintype()\<CR>:q\<CR>", 'x!')
+  call assert_equal(':', a)
+
+  call assert_equal('', getcmdwintype())
+endfunc
+
+func Test_getcmdwin_autocmd()
+  let s:seq = []
+  augroup CmdWin
+  au WinEnter * call add(s:seq, 'WinEnter ' .. win_getid())
+  au WinLeave * call add(s:seq, 'WinLeave ' .. win_getid())
+  au BufEnter * call add(s:seq, 'BufEnter ' .. bufnr())
+  au BufLeave * call add(s:seq, 'BufLeave ' .. bufnr())
+  au CmdWinEnter * call add(s:seq, 'CmdWinEnter ' .. win_getid())
+  au CmdWinLeave * call add(s:seq, 'CmdWinLeave ' .. win_getid())
+
+  let org_winid = win_getid()
+  let org_bufnr = bufnr()
+  call feedkeys("q::let a = getcmdwintype()\<CR>:let s:cmd_winid = win_getid()\<CR>:let s:cmd_bufnr = bufnr()\<CR>:q\<CR>", 'x!')
+  call assert_equal(':', a)
+  call assert_equal([
+	\ 'WinLeave ' .. org_winid,
+	\ 'WinEnter ' .. s:cmd_winid,
+	\ 'BufLeave ' .. org_bufnr,
+	\ 'BufEnter ' .. s:cmd_bufnr,
+	\ 'CmdWinEnter ' .. s:cmd_winid,
+	\ 'CmdWinLeave ' .. s:cmd_winid,
+	\ 'BufLeave ' .. s:cmd_bufnr,
+	\ 'WinLeave ' .. s:cmd_winid,
+	\ 'WinEnter ' .. org_winid,
+	\ 'BufEnter ' .. org_bufnr,
+	\ ], s:seq)
+
+  au!
+  augroup END
+endfunc
+
+func Test_cmdwin_bug()
+  let winid = win_getid()
+  sp
+  try
+    call feedkeys("q::call win_gotoid(" .. winid .. ")\<CR>:q\<CR>", 'x!')
+  catch /^Vim\%((\a\+)\)\=:E11/
+  endtry
+  bw!
+endfunc
+
+func Test_cmdwin_restore()
+  CheckScreendump
+
+  let lines =<< trim [SCRIPT]
+    augroup vimHints | au! | augroup END
+    call setline(1, range(30))
+    2split
+  [SCRIPT]
+  call writefile(lines, 'XTest_restore')
+
+  let buf = RunVimInTerminal('-S XTest_restore', {'rows': 12})
+  call TermWait(buf, 50)
+  call term_sendkeys(buf, "q:")
+  call VerifyScreenDump(buf, 'Test_cmdwin_restore_1', {})
+
+  " normal restore
+  call term_sendkeys(buf, ":q\<CR>")
+  call VerifyScreenDump(buf, 'Test_cmdwin_restore_2', {})
+
+  " restore after setting 'lines' with one window
+  call term_sendkeys(buf, ":close\<CR>")
+  call term_sendkeys(buf, "q:")
+  call term_sendkeys(buf, ":set lines=18\<CR>")
+  call term_sendkeys(buf, ":q\<CR>")
+  call VerifyScreenDump(buf, 'Test_cmdwin_restore_3', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('XTest_restore')
+endfunc
+
+func Test_cmdwin_no_terminal()
+  CheckFeature terminal
+  CheckNotMSWindows
+
+  let buf = RunVimInTerminal('', {'rows': 12})
+  call TermWait(buf, 50)
+  call term_sendkeys(buf, ":set cmdheight=2\<CR>")
+  call term_sendkeys(buf, "q:")
+  call term_sendkeys(buf, ":let buf = term_start(['/bin/echo'], #{hidden: 1})\<CR>")
+  call VerifyScreenDump(buf, 'Test_cmdwin_no_terminal', {})
+  call term_sendkeys(buf, ":q\<CR>")
+  call StopVimInTerminal(buf)
+endfunc
+
+func Test_cmdwin_feedkeys()
+  " This should not generate E488
+  call feedkeys("q:\<CR>", 'x')
+  " Using feedkeys with q: only should automatically close the cmd window
+  call feedkeys('q:', 'xt')
+  call assert_equal(1, winnr('$'))
+  call assert_equal('', getcmdwintype())
+endfunc
+
+" Tests for the issues fixed in 7.4.441.
+" When 'cedit' is set to Ctrl-C, opening the command window hangs Vim
+func Test_cmdwin_cedit()
+  exe "set cedit=\<C-c>"
+  normal! :
+  call assert_equal(1, winnr('$'))
+
+  let g:cmd_wintype = ''
+  func CmdWinType()
+      let g:cmd_wintype = getcmdwintype()
+      let g:wintype = win_gettype()
+      return ''
+  endfunc
+
+  call feedkeys("\<C-c>a\<C-R>=CmdWinType()\<CR>\<CR>")
+  echo input('')
+  call assert_equal('@', g:cmd_wintype)
+  call assert_equal('command', g:wintype)
+
+  set cedit&vim
+  delfunc CmdWinType
+endfunc
+
+" Test for CmdwinEnter autocmd
+func Test_cmdwin_autocmd()
+  augroup CmdWin
+    au!
+    autocmd BufLeave * if &buftype == '' | update | endif
+    autocmd CmdwinEnter * startinsert
+  augroup END
+
+  call assert_fails('call feedkeys("q:xyz\<CR>", "xt")', 'E492:')
+  call assert_equal('xyz', @:)
+
+  augroup CmdWin
+    au!
+  augroup END
+  augroup! CmdWin
+endfunc
+
+func Test_cmdwin_jump_to_win()
+  call assert_fails('call feedkeys("q:\<C-W>\<C-W>\<CR>", "xt")', 'E11:')
+  new
+  set modified
+  call assert_fails('call feedkeys("q/:qall\<CR>", "xt")', ['E37:', 'E162:'])
+  close!
+  call feedkeys("q/:close\<CR>", "xt")
+  call assert_equal(1, winnr('$'))
+  call feedkeys("q/:exit\<CR>", "xt")
+  call assert_equal(1, winnr('$'))
+
+  " opening command window twice should fail
+  call assert_beeps('call feedkeys("q:q:\<CR>\<CR>", "xt")')
+  call assert_equal(1, winnr('$'))
+endfunc
+
+func Test_cmdwin_tabpage()
+  tabedit
+  call assert_fails("silent norm q/g	:I\<Esc>", 'E11:')
+  tabclose!
+endfunc
+
+func Test_cmdwin_interrupted()
+  CheckScreendump
+
+  " aborting the :smile output caused the cmdline window to use the current
+  " buffer.
+  let lines =<< trim [SCRIPT]
+    au WinNew * smile
+  [SCRIPT]
+  call writefile(lines, 'XTest_cmdwin')
+
+  let buf = RunVimInTerminal('-S XTest_cmdwin', {'rows': 18})
+  " open cmdwin
+  call term_sendkeys(buf, "q:")
+  call WaitForAssert({-> assert_match('-- More --', term_getline(buf, 18))})
+  " quit more prompt for :smile command
+  call term_sendkeys(buf, "q")
+  call WaitForAssert({-> assert_match('^$', term_getline(buf, 18))})
+  " execute a simple command
+  call term_sendkeys(buf, "aecho 'done'\<CR>")
+  call VerifyScreenDump(buf, 'Test_cmdwin_interrupted', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('XTest_cmdwin')
+endfunc
+
+" Test for recursively getting multiple command line inputs
+func Test_cmdwin_multi_input()
+  call feedkeys(":\<C-R>=input('P: ')\<CR>\"cyan\<CR>\<CR>", 'xt')
+  call assert_equal('"cyan', @:)
+endfunc
+
+" Test for normal mode commands not supported in the cmd window
+func Test_cmdwin_blocked_commands()
+  call assert_fails('call feedkeys("q:\<C-T>\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-]>\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-^>\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:Q\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:Z\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<F1>\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>s\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>v\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>^\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>n\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>z\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>o\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>w\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>j\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>k\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>h\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>l\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>T\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>x\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>r\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>R\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>K\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>}\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>]\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>f\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>d\<CR>", "xt")', 'E11:')
+  call assert_fails('call feedkeys("q:\<C-W>g\<CR>", "xt")', 'E11:')
+endfunc
+
+" Close the Cmd-line window in insert mode using CTRL-C
+func Test_cmdwin_insert_mode_close()
+  %bw!
+  let s = ''
+  exe "normal q:a\<C-C>let s='Hello'\<CR>"
+  call assert_equal('Hello', s)
+  call assert_equal(1, winnr('$'))
+endfunc
+
+func Test_cmdwin_ex_mode_with_modifier()
+  " this was accessing memory after allocated text in Ex mode
+  new
+  call setline(1, ['some', 'text', 'lines'])
+  silent! call feedkeys("gQnormal vq:atopleft\<C-V>\<CR>\<CR>", 'xt')
+  bwipe!
+endfunc
+
+func s:ComplInCmdwin_GlobalCompletion(a, l, p)
+  return 'global'
+endfunc
+
+func s:ComplInCmdwin_LocalCompletion(a, l, p)
+  return 'local'
+endfunc
+
+func Test_compl_in_cmdwin()
+  set wildmenu wildchar=<Tab>
+  com! -nargs=1 -complete=command GetInput let input = <q-args>
+  com! -buffer TestCommand echo 'TestCommand'
+  let w:test_winvar = 'winvar'
+  let b:test_bufvar = 'bufvar'
+
+  " User-defined commands
+  let input = ''
+  call feedkeys("q:iGetInput T\<C-x>\<C-v>\<CR>", 'tx!')
+  call assert_equal('TestCommand', input)
+
+  let input = ''
+  call feedkeys("q::GetInput T\<Tab>\<CR>:q\<CR>", 'tx!')
+  call assert_equal('T', input)
+
+
+  com! -nargs=1 -complete=var GetInput let input = <q-args>
+  " Window-local variables
+  let input = ''
+  call feedkeys("q:iGetInput w:test_\<C-x>\<C-v>\<CR>", 'tx!')
+  call assert_equal('w:test_winvar', input)
+
+  let input = ''
+  call feedkeys("q::GetInput w:test_\<Tab>\<CR>:q\<CR>", 'tx!')
+  call assert_equal('w:test_', input)
+
+  " Buffer-local variables
+  let input = ''
+  call feedkeys("q:iGetInput b:test_\<C-x>\<C-v>\<CR>", 'tx!')
+  call assert_equal('b:test_bufvar', input)
+
+  let input = ''
+  call feedkeys("q::GetInput b:test_\<Tab>\<CR>:q\<CR>", 'tx!')
+  call assert_equal('b:test_', input)
+
+
+  " Argument completion of buffer-local command
+  func s:ComplInCmdwin_GlobalCompletionList(a, l, p)
+    return ['global']
+  endfunc
+
+  func s:ComplInCmdwin_LocalCompletionList(a, l, p)
+    return ['local']
+  endfunc
+
+  func s:ComplInCmdwin_CheckCompletion(arg)
+    call assert_equal('local', a:arg)
+  endfunc
+
+  com! -nargs=1 -complete=custom,<SID>ComplInCmdwin_GlobalCompletion
+       \ TestCommand call s:ComplInCmdwin_CheckCompletion(<q-args>)
+  com! -buffer -nargs=1 -complete=custom,<SID>ComplInCmdwin_LocalCompletion
+       \ TestCommand call s:ComplInCmdwin_CheckCompletion(<q-args>)
+  call feedkeys("q:iTestCommand \<Tab>\<CR>", 'tx!')
+
+  com! -nargs=1 -complete=customlist,<SID>ComplInCmdwin_GlobalCompletionList
+       \ TestCommand call s:ComplInCmdwin_CheckCompletion(<q-args>)
+  com! -buffer -nargs=1 -complete=customlist,<SID>ComplInCmdwin_LocalCompletionList
+       \ TestCommand call s:ComplInCmdwin_CheckCompletion(<q-args>)
+
+  call feedkeys("q:iTestCommand \<Tab>\<CR>", 'tx!')
+
+  func! s:ComplInCmdwin_CheckCompletion(arg)
+    call assert_equal('global', a:arg)
+  endfunc
+  new
+  call feedkeys("q:iTestCommand \<Tab>\<CR>", 'tx!')
+  quit
+
+  delfunc s:ComplInCmdwin_GlobalCompletion
+  delfunc s:ComplInCmdwin_LocalCompletion
+  delfunc s:ComplInCmdwin_GlobalCompletionList
+  delfunc s:ComplInCmdwin_LocalCompletionList
+  delfunc s:ComplInCmdwin_CheckCompletion
+
+  delcom -buffer TestCommand
+  delcom TestCommand
+  delcom GetInput
+  unlet w:test_winvar
+  unlet b:test_bufvar
+  set wildmenu& wildchar&
+endfunc
+
+func Test_cmdwin_ctrl_bsl()
+  " Using CTRL-\ CTRL-N in cmd window should close the window
+  call feedkeys("q:\<C-\>\<C-N>", 'xt')
+  call assert_equal('', getcmdwintype())
+endfunc
+
+
+" vim: shiftwidth=2 sts=2 expandtab