--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -1,622 +1,622 @@
-" This script is sourced while editing the .vim file with the tests.
-" When the script is successful the .res file will be created.
-" Errors are appended to the test.log file.
-"
-" To execute only specific test functions, add a second argument.  It will be
-" matched against the names of the Test_ function.  E.g.:
-"	../vim -u NONE -S runtest.vim test_channel.vim open_delay
-" The output can be found in the "messages" file.
-"
-" If the environment variable $TEST_FILTER is set then only test functions
-" matching this pattern are executed.  E.g. for sh/bash:
-"     export TEST_FILTER=Test_channel
-" For csh:
-"     setenv TEST_FILTER Test_channel
-"
-" If the environment variable $TEST_SKIP_PAT is set then test functions
-" matching this pattern will be skipped.  It's the opposite of $TEST_FILTER.
-"
-" While working on a test you can make $TEST_NO_RETRY non-empty to not retry:
-"     export TEST_NO_RETRY=yes
-"
-" To ignore failure for tests that are known to fail in a certain environment,
-" set $TEST_MAY_FAIL to a comma separated list of function names.  E.g. for
-" sh/bash:
-"     export TEST_MAY_FAIL=Test_channel_one,Test_channel_other
-" The failure report will then not be included in the test.log file and
-" "make test" will not fail.
-"
-" The test script may contain anything, only functions that start with
-" "Test_" are special.  These will be invoked and should contain assert
-" functions.  See test_assert.vim for an example.
-"
-" It is possible to source other files that contain "Test_" functions.  This
-" can speed up testing, since Vim does not need to restart.  But be careful
-" that the tests do not interfere with each other.
-"
-" If an error cannot be detected properly with an assert function add the
-" error to the v:errors list:
-"   call add(v:errors, 'test foo failed: Cannot find xyz')
-"
-" If preparation for each Test_ function is needed, define a SetUp function.
-" It will be called before each Test_ function.
-"
-" If cleanup after each Test_ function is needed, define a TearDown function.
-" It will be called after each Test_ function.
-"
-" When debugging a test it can be useful to add messages to v:errors:
-"	call add(v:errors, "this happened")
-
-
-" Without the +eval feature we can't run these tests, bail out.
-silent! while 0
-  qa!
-silent! endwhile
-
-" In the GUI we can always change the screen size.
-if has('gui_running')
-  set columns=80 lines=25
-endif
-
-" Check that the screen size is at least 24 x 80 characters.
-if &lines < 24 || &columns < 80
-  let error = 'Screen size too small! Tests require at least 24 lines with 80 characters, got ' .. &lines .. ' lines with ' .. &columns .. ' characters'
-  echoerr error
-  split test.log
-  $put =error
-  write
-  split messages
-  call append(line('$'), '')
-  call append(line('$'), 'From ' . expand('%') . ':')
-  call append(line('$'), error)
-  write
-  qa!
-endif
-
-if has('reltime')
-  let s:run_start_time = reltime()
-
-  if !filereadable('starttime')
-    " first test, store the overall test starting time
-    let s:test_start_time = localtime()
-    call writefile([string(s:test_start_time)], 'starttime')
-  else
-    " second or later test, read the overall test starting time
-    let s:test_start_time = readfile('starttime')[0]->str2nr()
-  endif
-endif
-
-" Always use forward slashes.
-set shellslash
-
-" Common with all tests on all systems.
-source setup.vim
-
-" For consistency run all tests with 'nocompatible' set.
-" This also enables use of line continuation.
-set nocp viminfo+=nviminfo
-
-" Use utf-8 by default, instead of whatever the system default happens to be.
-" Individual tests can overrule this at the top of the file and use
-" g:orig_encoding if needed.
-let g:orig_encoding = &encoding
-set encoding=utf-8
-
-" REDIR_TEST_TO_NULL has a very permissive SwapExists autocommand which is for
-" the test_name.vim file itself. Replace it here with a more restrictive one,
-" so we still catch mistakes.
-if has("win32")
-  " replace any '/' directory separators by '\\'
-  let s:test_script_fname = substitute(expand('%'), '/', '\\', 'g')
-else
-  let s:test_script_fname = expand('%')
-endif
-
-au! SwapExists * call HandleSwapExists()
-func HandleSwapExists()
-  if exists('g:ignoreSwapExists')
-    if type(g:ignoreSwapExists) == v:t_string
-      let v:swapchoice = g:ignoreSwapExists
-    endif
-    return
-  endif
-  " Ignore finding a swap file for the test script (the user might be
-  " editing it and do ":make test_name") and the output file.
-  " Report finding another swap file and chose 'q' to avoid getting stuck.
-  if expand('<afile>') == 'messages' || expand('<afile>') =~ s:test_script_fname
-    let v:swapchoice = 'e'
-  else
-    call assert_report('Unexpected swap file: ' .. v:swapname)
-    let v:swapchoice = 'q'
-  endif
-endfunc
-
-" Avoid stopping at the "hit enter" prompt
-set nomore
-
-" Output all messages in English.
-lang mess C
-
-" suppress menu translation
-if has('gui_running') && exists('did_install_default_menus')
-  source $VIMRUNTIME/delmenu.vim
-  set langmenu=none
-  source $VIMRUNTIME/menu.vim
-endif
-
-let s:srcdir = expand('%:p:h:h')
-
-if has('win32')
-  " avoid prompt that is long or contains a line break
-  let $PROMPT = '$P$G'
-  " On MS-Windows t_md and t_me are Vim specific escape sequences.
-  let s:t_bold = "\x1b[1m"
-  let s:t_normal = "\x1b[m"
-else
-  let s:t_bold = &t_md
-  let s:t_normal = &t_me
-endif
-
-if has('mac')
-  " In macOS, when starting a shell in a terminal, a bash deprecation warning
-  " message is displayed. This breaks the terminal test. Disable the warning
-  " message.
-  let $BASH_SILENCE_DEPRECATION_WARNING = 1
-endif
-
-
-" Prepare for calling test_garbagecollect_now().
-let v:testing = 1
-
-" By default, copy each buffer line into allocated memory, so that valgrind can
-" detect accessing memory before and after it.
-call test_override('alloc_lines', 1)
-
-" Support function: get the alloc ID by name.
-function GetAllocId(name)
-  exe 'split ' . s:srcdir . '/alloc.h'
-  let top = search('typedef enum')
-  if top == 0
-    call add(v:errors, 'typedef not found in alloc.h')
-  endif
-  let lnum = search('aid_' . a:name . ',')
-  if lnum == 0
-    call add(v:errors, 'Alloc ID ' . a:name . ' not defined')
-  endif
-  close
-  return lnum - top - 1
-endfunc
-
-if has('reltime')
-  let g:func_start = reltime()
-endif
-
-" Get the list of swap files in the current directory.
-func s:GetSwapFileList()
-  let save_dir = &directory
-  let &directory = '.'
-  let files = swapfilelist()
-  let &directory = save_dir
-
-  " remove a match with runtest.vim
-  let idx = indexof(files, 'v:val =~ "runtest.vim."')
-  if idx >= 0
-    call remove(files, idx)
-  endif
-
-  return files
-endfunc
-
-" A previous (failed) test run may have left swap files behind.  Delete them
-" before running tests again, they might interfere.
-for name in s:GetSwapFileList()
-  call delete(name)
-endfor
-unlet name
-
-
-" Invoked when a test takes too much time.
-func TestTimeout(id)
-  split test.log
-  call append(line('$'), '')
-  call append(line('$'), 'Test timed out: ' .. g:testfunc)
-  write
-  call add(v:errors, 'Test timed out: ' . g:testfunc)
-
-  cquit! 42
-endfunc
-
-func RunTheTest(test)
-  let prefix = ''
-  if has('reltime')
-    let prefix = strftime('%M:%S', localtime() - s:test_start_time) .. ' '
-    let g:func_start = reltime()
-  endif
-  echoconsole prefix .. 'Executing ' .. a:test
-
-  if has('timers')
-    " No test should take longer than 30 seconds.  If it takes longer we
-    " assume we are stuck and need to break out.
-    let test_timeout_timer = timer_start(30000, 'TestTimeout')
-  endif
-
-  " Avoid stopping at the "hit enter" prompt
-  set nomore
-
-  " Avoid a three second wait when a message is about to be overwritten by the
-  " mode message.
-  set noshowmode
-
-  " Clear any overrides, except "alloc_lines".
-  call test_override('ALL', 0)
-
-  " Some tests wipe out buffers.  To be consistent, always wipe out all
-  " buffers.
-  %bwipe!
-
-  " The test may change the current directory. Save and restore the
-  " directory after executing the test.
-  let save_cwd = getcwd()
-
-  if exists("*SetUp")
-    try
-      call SetUp()
-    catch
-      call add(v:errors, 'Caught exception in SetUp() before ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
-    endtry
-  endif
-
-  au VimLeavePre * call EarlyExit(g:testfunc)
-  if a:test =~ 'Test_nocatch_'
-    " Function handles errors itself.  This avoids skipping commands after the
-    " error.
-    let g:skipped_reason = ''
-    exe 'call ' . a:test
-    if g:skipped_reason != ''
-      call add(s:messages, '    Skipped')
-      call add(s:skipped, 'SKIPPED ' . a:test . ': ' . g:skipped_reason)
-    endif
-  else
-    try
-      exe 'call ' . a:test
-    catch /^\cskipped/
-      call add(s:messages, '    Skipped')
-      call add(s:skipped, 'SKIPPED ' . a:test . ': ' . substitute(v:exception, '^\S*\s\+', '',  ''))
-    catch
-      call add(v:errors, 'Caught exception in ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
-    endtry
-  endif
-  au! VimLeavePre
-
-  if a:test =~ '_terminal_'
-    " Terminal tests sometimes hang, give extra information
-    echoconsole 'After executing ' .. a:test
-  endif
-
-  " In case 'insertmode' was set and something went wrong, make sure it is
-  " reset to avoid trouble with anything else.
-  set noinsertmode
-
-  if exists("*TearDown")
-    try
-      call TearDown()
-    catch
-      call add(v:errors, 'Caught exception in TearDown() after ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
-    endtry
-  endif
-
-  if has('timers')
-    call timer_stop(test_timeout_timer)
-  endif
-
-  " Clear any autocommands and put back the catch-all for SwapExists.
-  au!
-  au SwapExists * call HandleSwapExists()
-
-  " Check for and close any stray popup windows.
-  if has('popupwin')
-    call assert_equal([], popup_list(), 'Popup is still present')
-    call popup_clear(1)
-  endif
-
-  if filereadable('guidialogfile')
-    call add(v:errors, "Unexpected dialog: " .. readfile('guidialogfile')->join('<NL>'))
-    call delete('guidialogfile')
-  endif
-
-  " Close any extra tab pages and windows and make the current one not modified.
-  while tabpagenr('$') > 1
-    let winid = win_getid()
-    quit!
-    if winid == win_getid()
-      echoerr 'Could not quit window'
-      break
-    endif
-  endwhile
-
-  while 1
-    let wincount = winnr('$')
-    if wincount == 1
-      break
-    endif
-    bwipe!
-    if wincount == winnr('$')
-      " Did not manage to close a window.
-      only!
-      break
-    endif
-  endwhile
-
-  exe 'cd ' . save_cwd
-
-  if a:test =~ '_terminal_'
-    " Terminal tests sometimes hang, give extra information
-    echoconsole 'Finished ' . a:test
-  endif
-
-  let message = 'Executed ' . a:test
-  if has('reltime')
-    let message ..= repeat(' ', 50 - len(message))
-    let time = reltime(g:func_start)
-    if reltimefloat(time) > 0.1
-      let message = s:t_bold .. message
-    endif
-    let message ..= ' in ' .. reltimestr(time) .. ' seconds'
-    if reltimefloat(time) > 0.1
-      let message ..= s:t_normal
-    endif
-  endif
-  call add(s:messages, message)
-  let s:done += 1
-
-  " close any split windows
-  while winnr('$') > 1
-    bwipe!
-  endwhile
-
-  " May be editing some buffer, wipe it out.  Then we may end up in another
-  " buffer, continue until we end up in an empty no-name buffer without a swap
-  " file.
-  while bufname() != '' || execute('swapname') !~ 'No swap file'
-    let bn = bufnr()
-
-    noswapfile bwipe!
-
-    if bn == bufnr()
-      " avoid getting stuck in the same buffer
-      break
-    endif
-  endwhile
-
-  " Check if the test has left any swap files behind.  Delete them before
-  " running tests again, they might interfere.
-  let swapfiles = s:GetSwapFileList()
-  if len(swapfiles) > 0
-    call add(s:messages, "Found swap files: " .. string(swapfiles))
-    for name in swapfiles
-      call delete(name)
-    endfor
-  endif
-endfunc
-
-func AfterTheTest(func_name)
-  if len(v:errors) > 0
-    if match(s:may_fail_list, '^' .. a:func_name) >= 0
-      let s:fail_expected += 1
-      call add(s:errors_expected, 'Found errors in ' . g:testfunc . ':')
-      call extend(s:errors_expected, v:errors)
-    else
-      let s:fail += 1
-      call add(s:errors, 'Found errors in ' . g:testfunc . ':')
-      call extend(s:errors, v:errors)
-    endif
-    let v:errors = []
-  endif
-endfunc
-
-func EarlyExit(test)
-  " It's OK for the test we use to test the quit detection.
-  if a:test != 'Test_zz_quit_detected()'
-    call add(v:errors, v:errmsg)
-    call add(v:errors, 'Test caused Vim to exit: ' . a:test)
-  endif
-
-  call FinishTesting()
-endfunc
-
-" This function can be called by a test if it wants to abort testing.
-func FinishTesting()
-  call AfterTheTest('')
-
-  " Don't write viminfo on exit.
-  set viminfo=
-
-  " Clean up files created by setup.vim
-  call delete('XfakeHOME', 'rf')
-
-  if s:fail == 0 && s:fail_expected == 0
-    " Success, create the .res file so that make knows it's done.
-    exe 'split ' . fnamemodify(g:testname, ':r') . '.res'
-    write
-  endif
-
-  if len(s:errors) > 0
-    " Append errors to test.log
-    split test.log
-    call append(line('$'), '')
-    call append(line('$'), 'From ' . g:testname . ':')
-    call append(line('$'), s:errors)
-    write
-  endif
-
-  if s:done == 0
-    if s:filtered > 0
-      if $TEST_FILTER != ''
-        let message = "NO tests match $TEST_FILTER: '" .. $TEST_FILTER .. "'"
-      else
-        let message = "ALL tests match $TEST_SKIP_PAT: '" .. $TEST_SKIP_PAT .. "'"
-      endif
-    else
-      let message = 'NO tests executed'
-    endif
-  else
-    if s:filtered > 0
-      call add(s:messages, "Filtered " .. s:filtered .. " tests with $TEST_FILTER and $TEST_SKIP_PAT")
-    endif
-    let message = 'Executed ' . s:done . (s:done > 1 ? ' tests' : ' test')
-  endif
-  if s:done > 0 && has('reltime')
-    let message = s:t_bold .. message .. repeat(' ', 40 - len(message))
-    let message ..= ' in ' .. reltimestr(reltime(s:run_start_time)) .. ' seconds'
-    let message ..= s:t_normal
-  endif
-  echo message
-  call add(s:messages, message)
-  if s:fail > 0
-    let message = s:fail . ' FAILED:'
-    echo message
-    call add(s:messages, message)
-    call extend(s:messages, s:errors)
-  endif
-  if s:fail_expected > 0
-    let message = s:fail_expected . ' FAILED (matching $TEST_MAY_FAIL):'
-    echo message
-    call add(s:messages, message)
-    call extend(s:messages, s:errors_expected)
-  endif
-
-  " Add SKIPPED messages
-  call extend(s:messages, s:skipped)
-
-  " Append messages to the file "messages"
-  split messages
-  call append(line('$'), '')
-  call append(line('$'), 'From ' . g:testname . ':')
-  call append(line('$'), s:messages)
-  write
-
-  qall!
-endfunc
-
-" Source the test script.  First grab the file name, in case the script
-" navigates away.  g:testname can be used by the tests.
-let g:testname = expand('%')
-let s:done = 0
-let s:fail = 0
-let s:fail_expected = 0
-let s:errors = []
-let s:errors_expected = []
-let s:messages = []
-let s:skipped = []
-if expand('%') =~ 'test_vimscript.vim'
-  " this test has intentional errors, don't use try/catch.
-  source %
-else
-  try
-    source %
-  catch /^\cskipped/
-    call add(s:messages, '    Skipped')
-    call add(s:skipped, 'SKIPPED ' . expand('%') . ': ' . substitute(v:exception, '^\S*\s\+', '',  ''))
-  catch
-    let s:fail += 1
-    call add(s:errors, 'Caught exception: ' . v:exception . ' @ ' . v:throwpoint)
-  endtry
-endif
-
-" Delete the .res file, it may change behavior for completion
-call delete(fnamemodify(g:testname, ':r') .. '.res')
-
-" Locate Test_ functions and execute them.
-redir @q
-silent function /^Test_
-redir END
-let s:tests = split(substitute(@q, '\(function\|def\) \(\k*()\)', '\2', 'g'))
-
-" If there is an extra argument filter the function names against it.
-if argc() > 1
-  let s:tests = filter(s:tests, 'v:val =~ argv(1)')
-endif
-
-" If the environment variable $TEST_FILTER is set then filter the function
-" names against it.
-let s:filtered = 0
-if $TEST_FILTER != ''
-  let s:filtered = len(s:tests)
-  let s:tests = filter(s:tests, 'v:val =~ $TEST_FILTER')
-  let s:filtered -= len(s:tests)
-endif
-
-let s:may_fail_list = []
-if $TEST_MAY_FAIL != ''
-  " Split the list at commas and add () to make it match g:testfunc.
-  let s:may_fail_list = split($TEST_MAY_FAIL, ',')->map({i, v -> v .. '()'})
-endif
-
-" Execute the tests in alphabetical order.
-for g:testfunc in sort(s:tests)
-  if $TEST_SKIP_PAT != '' && g:testfunc =~ $TEST_SKIP_PAT
-    call add(s:messages, g:testfunc .. ' matches $TEST_SKIP_PAT')
-    let s:filtered += 1
-    continue
-  endif
-
-  " Silence, please!
-  set belloff=all
-  let prev_error = ''
-  let total_errors = []
-  let g:run_nr = 1
-
-  " A test can set g:test_is_flaky to retry running the test.
-  let g:test_is_flaky = 0
-
-  let starttime = strftime("%H:%M:%S")
-  call RunTheTest(g:testfunc)
-
-  " Repeat a flaky test.  Give up when:
-  " - $TEST_NO_RETRY is not empty
-  " - it fails again with the same message
-  " - it fails five times (with a different message)
-  if len(v:errors) > 0
-        \ && $TEST_NO_RETRY == ''
-        \ && g:test_is_flaky
-    while 1
-      call add(s:messages, 'Found errors in ' .. g:testfunc .. ':')
-      call extend(s:messages, v:errors)
-
-      let endtime = strftime("%H:%M:%S")
-      call add(total_errors, $'Run {g:run_nr}, {starttime} - {endtime}:')
-      call extend(total_errors, v:errors)
-
-      if g:run_nr >= 5 || prev_error == v:errors[0]
-        call add(total_errors, 'Flaky test failed too often, giving up')
-        let v:errors = total_errors
-        break
-      endif
-
-      call add(s:messages, 'Flaky test failed, running it again')
-
-      " Flakiness is often caused by the system being very busy.  Sleep a
-      " couple of seconds to have a higher chance of succeeding the second
-      " time.
-      sleep 2
-
-      let prev_error = v:errors[0]
-      let v:errors = []
-      let g:run_nr += 1
-
-      let starttime = strftime("%H:%M:%S")
-      call RunTheTest(g:testfunc)
-
-      if len(v:errors) == 0
-        " Test passed on rerun.
-        break
-      endif
-    endwhile
-  endif
-
-  call AfterTheTest(g:testfunc)
-endfor
-
-call FinishTesting()
-
-" vim: shiftwidth=2 sts=2 expandtab
+" This script is sourced while editing the .vim file with the tests.
+" When the script is successful the .res file will be created.
+" Errors are appended to the test.log file.
+"
+" To execute only specific test functions, add a second argument.  It will be
+" matched against the names of the Test_ function.  E.g.:
+"	../vim -u NONE -S runtest.vim test_channel.vim open_delay
+" The output can be found in the "messages" file.
+"
+" If the environment variable $TEST_FILTER is set then only test functions
+" matching this pattern are executed.  E.g. for sh/bash:
+"     export TEST_FILTER=Test_channel
+" For csh:
+"     setenv TEST_FILTER Test_channel
+"
+" If the environment variable $TEST_SKIP_PAT is set then test functions
+" matching this pattern will be skipped.  It's the opposite of $TEST_FILTER.
+"
+" While working on a test you can make $TEST_NO_RETRY non-empty to not retry:
+"     export TEST_NO_RETRY=yes
+"
+" To ignore failure for tests that are known to fail in a certain environment,
+" set $TEST_MAY_FAIL to a comma separated list of function names.  E.g. for
+" sh/bash:
+"     export TEST_MAY_FAIL=Test_channel_one,Test_channel_other
+" The failure report will then not be included in the test.log file and
+" "make test" will not fail.
+"
+" The test script may contain anything, only functions that start with
+" "Test_" are special.  These will be invoked and should contain assert
+" functions.  See test_assert.vim for an example.
+"
+" It is possible to source other files that contain "Test_" functions.  This
+" can speed up testing, since Vim does not need to restart.  But be careful
+" that the tests do not interfere with each other.
+"
+" If an error cannot be detected properly with an assert function add the
+" error to the v:errors list:
+"   call add(v:errors, 'test foo failed: Cannot find xyz')
+"
+" If preparation for each Test_ function is needed, define a SetUp function.
+" It will be called before each Test_ function.
+"
+" If cleanup after each Test_ function is needed, define a TearDown function.
+" It will be called after each Test_ function.
+"
+" When debugging a test it can be useful to add messages to v:errors:
+"	call add(v:errors, "this happened")
+
+
+" Without the +eval feature we can't run these tests, bail out.
+silent! while 0
+  qa!
+silent! endwhile
+
+" In the GUI we can always change the screen size.
+if has('gui_running')
+  set columns=80 lines=25
+endif
+
+" Check that the screen size is at least 24 x 80 characters.
+if &lines < 24 || &columns < 80
+  let error = 'Screen size too small! Tests require at least 24 lines with 80 characters, got ' .. &lines .. ' lines with ' .. &columns .. ' characters'
+  echoerr error
+  split test.log
+  $put =error
+  write
+  split messages
+  call append(line('$'), '')
+  call append(line('$'), 'From ' . expand('%') . ':')
+  call append(line('$'), error)
+  write
+  qa!
+endif
+
+if has('reltime')
+  let s:run_start_time = reltime()
+
+  if !filereadable('starttime')
+    " first test, store the overall test starting time
+    let s:test_start_time = localtime()
+    call writefile([string(s:test_start_time)], 'starttime')
+  else
+    " second or later test, read the overall test starting time
+    let s:test_start_time = readfile('starttime')[0]->str2nr()
+  endif
+endif
+
+" Always use forward slashes.
+set shellslash
+
+" Common with all tests on all systems.
+source setup.vim
+
+" For consistency run all tests with 'nocompatible' set.
+" This also enables use of line continuation.
+set nocp viminfo+=nviminfo
+
+" Use utf-8 by default, instead of whatever the system default happens to be.
+" Individual tests can overrule this at the top of the file and use
+" g:orig_encoding if needed.
+let g:orig_encoding = &encoding
+set encoding=utf-8
+
+" REDIR_TEST_TO_NULL has a very permissive SwapExists autocommand which is for
+" the test_name.vim file itself. Replace it here with a more restrictive one,
+" so we still catch mistakes.
+if has("win32")
+  " replace any '/' directory separators by '\\'
+  let s:test_script_fname = substitute(expand('%'), '/', '\\', 'g')
+else
+  let s:test_script_fname = expand('%')
+endif
+
+au! SwapExists * call HandleSwapExists()
+func HandleSwapExists()
+  if exists('g:ignoreSwapExists')
+    if type(g:ignoreSwapExists) == v:t_string
+      let v:swapchoice = g:ignoreSwapExists
+    endif
+    return
+  endif
+  " Ignore finding a swap file for the test script (the user might be
+  " editing it and do ":make test_name") and the output file.
+  " Report finding another swap file and chose 'q' to avoid getting stuck.
+  if expand('<afile>') == 'messages' || expand('<afile>') =~ s:test_script_fname
+    let v:swapchoice = 'e'
+  else
+    call assert_report('Unexpected swap file: ' .. v:swapname)
+    let v:swapchoice = 'q'
+  endif
+endfunc
+
+" Avoid stopping at the "hit enter" prompt
+set nomore
+
+" Output all messages in English.
+lang mess C
+
+" suppress menu translation
+if has('gui_running') && exists('did_install_default_menus')
+  source $VIMRUNTIME/delmenu.vim
+  set langmenu=none
+  source $VIMRUNTIME/menu.vim
+endif
+
+let s:srcdir = expand('%:p:h:h')
+
+if has('win32')
+  " avoid prompt that is long or contains a line break
+  let $PROMPT = '$P$G'
+  " On MS-Windows t_md and t_me are Vim specific escape sequences.
+  let s:t_bold = "\x1b[1m"
+  let s:t_normal = "\x1b[m"
+else
+  let s:t_bold = &t_md
+  let s:t_normal = &t_me
+endif
+
+if has('mac')
+  " In macOS, when starting a shell in a terminal, a bash deprecation warning
+  " message is displayed. This breaks the terminal test. Disable the warning
+  " message.
+  let $BASH_SILENCE_DEPRECATION_WARNING = 1
+endif
+
+
+" Prepare for calling test_garbagecollect_now().
+let v:testing = 1
+
+" By default, copy each buffer line into allocated memory, so that valgrind can
+" detect accessing memory before and after it.
+call test_override('alloc_lines', 1)
+
+" Support function: get the alloc ID by name.
+function GetAllocId(name)
+  exe 'split ' . s:srcdir . '/alloc.h'
+  let top = search('typedef enum')
+  if top == 0
+    call add(v:errors, 'typedef not found in alloc.h')
+  endif
+  let lnum = search('aid_' . a:name . ',')
+  if lnum == 0
+    call add(v:errors, 'Alloc ID ' . a:name . ' not defined')
+  endif
+  close
+  return lnum - top - 1
+endfunc
+
+if has('reltime')
+  let g:func_start = reltime()
+endif
+
+" Get the list of swap files in the current directory.
+func s:GetSwapFileList()
+  let save_dir = &directory
+  let &directory = '.'
+  let files = swapfilelist()
+  let &directory = save_dir
+
+  " remove a match with runtest.vim
+  let idx = indexof(files, 'v:val =~ "runtest.vim."')
+  if idx >= 0
+    call remove(files, idx)
+  endif
+
+  return files
+endfunc
+
+" A previous (failed) test run may have left swap files behind.  Delete them
+" before running tests again, they might interfere.
+for name in s:GetSwapFileList()
+  call delete(name)
+endfor
+unlet name
+
+
+" Invoked when a test takes too much time.
+func TestTimeout(id)
+  split test.log
+  call append(line('$'), '')
+  call append(line('$'), 'Test timed out: ' .. g:testfunc)
+  write
+  call add(v:errors, 'Test timed out: ' . g:testfunc)
+
+  cquit! 42
+endfunc
+
+func RunTheTest(test)
+  let prefix = ''
+  if has('reltime')
+    let prefix = strftime('%M:%S', localtime() - s:test_start_time) .. ' '
+    let g:func_start = reltime()
+  endif
+  echoconsole prefix .. 'Executing ' .. a:test
+
+  if has('timers')
+    " No test should take longer than 30 seconds.  If it takes longer we
+    " assume we are stuck and need to break out.
+    let test_timeout_timer = timer_start(30000, 'TestTimeout')
+  endif
+
+  " Avoid stopping at the "hit enter" prompt
+  set nomore
+
+  " Avoid a three second wait when a message is about to be overwritten by the
+  " mode message.
+  set noshowmode
+
+  " Clear any overrides, except "alloc_lines".
+  call test_override('ALL', 0)
+
+  " Some tests wipe out buffers.  To be consistent, always wipe out all
+  " buffers.
+  %bwipe!
+
+  " The test may change the current directory. Save and restore the
+  " directory after executing the test.
+  let save_cwd = getcwd()
+
+  if exists("*SetUp")
+    try
+      call SetUp()
+    catch
+      call add(v:errors, 'Caught exception in SetUp() before ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
+    endtry
+  endif
+
+  au VimLeavePre * call EarlyExit(g:testfunc)
+  if a:test =~ 'Test_nocatch_'
+    " Function handles errors itself.  This avoids skipping commands after the
+    " error.
+    let g:skipped_reason = ''
+    exe 'call ' . a:test
+    if g:skipped_reason != ''
+      call add(s:messages, '    Skipped')
+      call add(s:skipped, 'SKIPPED ' . a:test . ': ' . g:skipped_reason)
+    endif
+  else
+    try
+      exe 'call ' . a:test
+    catch /^\cskipped/
+      call add(s:messages, '    Skipped')
+      call add(s:skipped, 'SKIPPED ' . a:test . ': ' . substitute(v:exception, '^\S*\s\+', '',  ''))
+    catch
+      call add(v:errors, 'Caught exception in ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
+    endtry
+  endif
+  au! VimLeavePre
+
+  if a:test =~ '_terminal_'
+    " Terminal tests sometimes hang, give extra information
+    echoconsole 'After executing ' .. a:test
+  endif
+
+  " In case 'insertmode' was set and something went wrong, make sure it is
+  " reset to avoid trouble with anything else.
+  set noinsertmode
+
+  if exists("*TearDown")
+    try
+      call TearDown()
+    catch
+      call add(v:errors, 'Caught exception in TearDown() after ' . a:test . ': ' . v:exception . ' @ ' . v:throwpoint)
+    endtry
+  endif
+
+  if has('timers')
+    call timer_stop(test_timeout_timer)
+  endif
+
+  " Clear any autocommands and put back the catch-all for SwapExists.
+  au!
+  au SwapExists * call HandleSwapExists()
+
+  " Check for and close any stray popup windows.
+  if has('popupwin')
+    call assert_equal([], popup_list(), 'Popup is still present')
+    call popup_clear(1)
+  endif
+
+  if filereadable('guidialogfile')
+    call add(v:errors, "Unexpected dialog: " .. readfile('guidialogfile')->join('<NL>'))
+    call delete('guidialogfile')
+  endif
+
+  " Close any extra tab pages and windows and make the current one not modified.
+  while tabpagenr('$') > 1
+    let winid = win_getid()
+    quit!
+    if winid == win_getid()
+      echoerr 'Could not quit window'
+      break
+    endif
+  endwhile
+
+  while 1
+    let wincount = winnr('$')
+    if wincount == 1
+      break
+    endif
+    bwipe!
+    if wincount == winnr('$')
+      " Did not manage to close a window.
+      only!
+      break
+    endif
+  endwhile
+
+  exe 'cd ' . save_cwd
+
+  if a:test =~ '_terminal_'
+    " Terminal tests sometimes hang, give extra information
+    echoconsole 'Finished ' . a:test
+  endif
+
+  let message = 'Executed ' . a:test
+  if has('reltime')
+    let message ..= repeat(' ', 50 - len(message))
+    let time = reltime(g:func_start)
+    if reltimefloat(time) > 0.1
+      let message = s:t_bold .. message
+    endif
+    let message ..= ' in ' .. reltimestr(time) .. ' seconds'
+    if reltimefloat(time) > 0.1
+      let message ..= s:t_normal
+    endif
+  endif
+  call add(s:messages, message)
+  let s:done += 1
+
+  " close any split windows
+  while winnr('$') > 1
+    bwipe!
+  endwhile
+
+  " May be editing some buffer, wipe it out.  Then we may end up in another
+  " buffer, continue until we end up in an empty no-name buffer without a swap
+  " file.
+  while bufname() != '' || execute('swapname') !~ 'No swap file'
+    let bn = bufnr()
+
+    noswapfile bwipe!
+
+    if bn == bufnr()
+      " avoid getting stuck in the same buffer
+      break
+    endif
+  endwhile
+
+  " Check if the test has left any swap files behind.  Delete them before
+  " running tests again, they might interfere.
+  let swapfiles = s:GetSwapFileList()
+  if len(swapfiles) > 0
+    call add(s:messages, "Found swap files: " .. string(swapfiles))
+    for name in swapfiles
+      call delete(name)
+    endfor
+  endif
+endfunc
+
+func AfterTheTest(func_name)
+  if len(v:errors) > 0
+    if match(s:may_fail_list, '^' .. a:func_name) >= 0
+      let s:fail_expected += 1
+      call add(s:errors_expected, 'Found errors in ' . g:testfunc . ':')
+      call extend(s:errors_expected, v:errors)
+    else
+      let s:fail += 1
+      call add(s:errors, 'Found errors in ' . g:testfunc . ':')
+      call extend(s:errors, v:errors)
+    endif
+    let v:errors = []
+  endif
+endfunc
+
+func EarlyExit(test)
+  " It's OK for the test we use to test the quit detection.
+  if a:test != 'Test_zz_quit_detected()'
+    call add(v:errors, v:errmsg)
+    call add(v:errors, 'Test caused Vim to exit: ' . a:test)
+  endif
+
+  call FinishTesting()
+endfunc
+
+" This function can be called by a test if it wants to abort testing.
+func FinishTesting()
+  call AfterTheTest('')
+
+  " Don't write viminfo on exit.
+  set viminfo=
+
+  " Clean up files created by setup.vim
+  call delete('XfakeHOME', 'rf')
+
+  if s:fail == 0 && s:fail_expected == 0
+    " Success, create the .res file so that make knows it's done.
+    exe 'split ' . fnamemodify(g:testname, ':r') . '.res'
+    write
+  endif
+
+  if len(s:errors) > 0
+    " Append errors to test.log
+    split test.log
+    call append(line('$'), '')
+    call append(line('$'), 'From ' . g:testname . ':')
+    call append(line('$'), s:errors)
+    write
+  endif
+
+  if s:done == 0
+    if s:filtered > 0
+      if $TEST_FILTER != ''
+        let message = "NO tests match $TEST_FILTER: '" .. $TEST_FILTER .. "'"
+      else
+        let message = "ALL tests match $TEST_SKIP_PAT: '" .. $TEST_SKIP_PAT .. "'"
+      endif
+    else
+      let message = 'NO tests executed'
+    endif
+  else
+    if s:filtered > 0
+      call add(s:messages, "Filtered " .. s:filtered .. " tests with $TEST_FILTER and $TEST_SKIP_PAT")
+    endif
+    let message = 'Executed ' . s:done . (s:done > 1 ? ' tests' : ' test')
+  endif
+  if s:done > 0 && has('reltime')
+    let message = s:t_bold .. message .. repeat(' ', 40 - len(message))
+    let message ..= ' in ' .. reltimestr(reltime(s:run_start_time)) .. ' seconds'
+    let message ..= s:t_normal
+  endif
+  echo message
+  call add(s:messages, message)
+  if s:fail > 0
+    let message = s:fail . ' FAILED:'
+    echo message
+    call add(s:messages, message)
+    call extend(s:messages, s:errors)
+  endif
+  if s:fail_expected > 0
+    let message = s:fail_expected . ' FAILED (matching $TEST_MAY_FAIL):'
+    echo message
+    call add(s:messages, message)
+    call extend(s:messages, s:errors_expected)
+  endif
+
+  " Add SKIPPED messages
+  call extend(s:messages, s:skipped)
+
+  " Append messages to the file "messages"
+  split messages
+  call append(line('$'), '')
+  call append(line('$'), 'From ' . g:testname . ':')
+  call append(line('$'), s:messages)
+  write
+
+  qall!
+endfunc
+
+" Source the test script.  First grab the file name, in case the script
+" navigates away.  g:testname can be used by the tests.
+let g:testname = expand('%')
+let s:done = 0
+let s:fail = 0
+let s:fail_expected = 0
+let s:errors = []
+let s:errors_expected = []
+let s:messages = []
+let s:skipped = []
+if expand('%') =~ 'test_vimscript.vim'
+  " this test has intentional errors, don't use try/catch.
+  source %
+else
+  try
+    source %
+  catch /^\cskipped/
+    call add(s:messages, '    Skipped')
+    call add(s:skipped, 'SKIPPED ' . expand('%') . ': ' . substitute(v:exception, '^\S*\s\+', '',  ''))
+  catch
+    let s:fail += 1
+    call add(s:errors, 'Caught exception: ' . v:exception . ' @ ' . v:throwpoint)
+  endtry
+endif
+
+" Delete the .res file, it may change behavior for completion
+call delete(fnamemodify(g:testname, ':r') .. '.res')
+
+" Locate Test_ functions and execute them.
+redir @q
+silent function /^Test_
+redir END
+let s:tests = split(substitute(@q, '\(function\|def\) \(\k*()\)', '\2', 'g'))
+
+" If there is an extra argument filter the function names against it.
+if argc() > 1
+  let s:tests = filter(s:tests, 'v:val =~ argv(1)')
+endif
+
+" If the environment variable $TEST_FILTER is set then filter the function
+" names against it.
+let s:filtered = 0
+if $TEST_FILTER != ''
+  let s:filtered = len(s:tests)
+  let s:tests = filter(s:tests, 'v:val =~ $TEST_FILTER')
+  let s:filtered -= len(s:tests)
+endif
+
+let s:may_fail_list = []
+if $TEST_MAY_FAIL != ''
+  " Split the list at commas and add () to make it match g:testfunc.
+  let s:may_fail_list = split($TEST_MAY_FAIL, ',')->map({i, v -> v .. '()'})
+endif
+
+" Execute the tests in alphabetical order.
+for g:testfunc in sort(s:tests)
+  if $TEST_SKIP_PAT != '' && g:testfunc =~ $TEST_SKIP_PAT
+    call add(s:messages, g:testfunc .. ' matches $TEST_SKIP_PAT')
+    let s:filtered += 1
+    continue
+  endif
+
+  " Silence, please!
+  set belloff=all
+  let prev_error = ''
+  let total_errors = []
+  let g:run_nr = 1
+
+  " A test can set g:test_is_flaky to retry running the test.
+  let g:test_is_flaky = 0
+
+  let starttime = strftime("%H:%M:%S")
+  call RunTheTest(g:testfunc)
+
+  " Repeat a flaky test.  Give up when:
+  " - $TEST_NO_RETRY is not empty
+  " - it fails again with the same message
+  " - it fails five times (with a different message)
+  if len(v:errors) > 0
+        \ && $TEST_NO_RETRY == ''
+        \ && g:test_is_flaky
+    while 1
+      call add(s:messages, 'Found errors in ' .. g:testfunc .. ':')
+      call extend(s:messages, v:errors)
+
+      let endtime = strftime("%H:%M:%S")
+      call add(total_errors, $'Run {g:run_nr}, {starttime} - {endtime}:')
+      call extend(total_errors, v:errors)
+
+      if g:run_nr >= 5 || prev_error == v:errors[0]
+        call add(total_errors, 'Flaky test failed too often, giving up')
+        let v:errors = total_errors
+        break
+      endif
+
+      call add(s:messages, 'Flaky test failed, running it again')
+
+      " Flakiness is often caused by the system being very busy.  Sleep a
+      " couple of seconds to have a higher chance of succeeding the second
+      " time.
+      sleep 2
+
+      let prev_error = v:errors[0]
+      let v:errors = []
+      let g:run_nr += 1
+
+      let starttime = strftime("%H:%M:%S")
+      call RunTheTest(g:testfunc)
+
+      if len(v:errors) == 0
+        " Test passed on rerun.
+        break
+      endif
+    endwhile
+  endif
+
+  call AfterTheTest(g:testfunc)
+endfor
+
+call FinishTesting()
+
+" vim: shiftwidth=2 sts=2 expandtab