diff --git a/runtime/syntax/testdir/README.txt b/runtime/syntax/testdir/README.txt
index d6cd98e..3b1b9ae 100644
--- a/runtime/syntax/testdir/README.txt
+++ b/runtime/syntax/testdir/README.txt
@@ -124,6 +124,31 @@
 test.
 
 
+Viewing generated screendumps
+-----------------------------
+
+You may also wish to look at the whole batch of failed screendumps after
+running "make test".  Source the "viewdumps.vim" script for this task:
+
+	[VIMRUNTIME=../..] \
+	../../src/vim --clean -S testdir/viewdumps.vim \
+				[testdir/dumps/java_*.dump ...]
+
+By default, all screendumps found in the "failed" directory will be added to
+the argument list and then the first one will be loaded.  Loaded screendumps
+that bear filenames of screendumps found in the "dumps" directory will be
+rendering the contents of any such pair of files and the difference between
+them (:help term_dumpdiff()); otherwise, they will be rendering own contents
+(:help term_dumpload()).  Remember to execute :edit when occasionally you see
+raw file contents instead of rendered.
+
+At any time, you can add, list, and abandon other screendumps:
+
+	:$argedit testdir/dumps/java_*.dump
+	:args
+	:qall
+
+The listing of argument commands can be found under :help buffer-list.
 
 
 TODO: run test for one specific filetype
diff --git a/runtime/syntax/testdir/runtest.vim b/runtime/syntax/testdir/runtest.vim
index 7c48b3f..f9c0db0 100644
--- a/runtime/syntax/testdir/runtest.vim
+++ b/runtime/syntax/testdir/runtest.vim
@@ -118,7 +118,7 @@
 
   if exists("$VIM_SYNTAX_SELF_TESTING")
     let dirpath = 'input/selftestdir/'
-    let fnames = readdir(dirpath, {fname -> fname !~ '^README.txt$'})
+    let fnames = readdir(dirpath, {fname -> fname !~ '^README\.txt$'})
   else
     let dirpath = 'input/'
     let fnames = readdir(dirpath, {fname -> fname !~ '\~$' && fname =~ '^.\+\..\+$'})
@@ -409,6 +409,12 @@
   call Message('OK: ' .. ok_count)
   call Message('FAILED: ' .. len(failed_tests) .. ': ' .. string(failed_tests))
   call Message('skipped: ' .. skipped_count)
+
+  if !empty(failed_tests)
+    call Message('')
+    call Message('View generated screendumps with "../../src/vim --clean -S testdir/viewdumps.vim"')
+  endif
+
   call AppendMessages('== SUMMARY ==')
 
   if len(failed_tests) > 0
diff --git a/runtime/syntax/testdir/viewdumps.vim b/runtime/syntax/testdir/viewdumps.vim
new file mode 100644
index 0000000..0fbfade
--- /dev/null
+++ b/runtime/syntax/testdir/viewdumps.vim
@@ -0,0 +1,77 @@
+vim9script
+
+# Support sourcing this script from this directory or any other directory in
+# the direct path that leads to the project's root directory.
+const failed_path: string = finddir('failed', getcwd() .. '/**', -1)
+  ->filter(((cwdpath: string) => (_: number, dirpath: string) =>
+	cwdpath =~ '\<syntax\>' || dirpath =~ '\<syntax\>')(getcwd()))
+  ->get(-1, '') .. '/'
+var error: string = null_string
+
+if failed_path == '/'
+  error = 'No such directory: "failed"'
+else
+  const failed_fnames: string = failed_path .. readdir(failed_path,
+	  (fname: string) => fname =~ '^.\+\.dump$')
+    ->join(' ' .. failed_path)
+
+  if failed_fnames =~ 'failed/$'
+    error = 'No such file: "*.dump"'
+  else
+    exec ':0argedit ' .. failed_fnames
+    buffers
+  endif
+endif
+
+def Render()
+  const failed_fname: string = bufname()
+  try
+    setlocal suffixesadd=.dump
+    const dumps_fname: string = findfile(
+			fnamemodify(failed_fname, ':p:t'),
+			fnamemodify(failed_fname, ':p:h:h') .. '/dumps')
+    if filereadable(dumps_fname)
+      term_dumpdiff(failed_fname, dumps_fname)
+    else
+      term_dumpload(failed_fname)
+    endif
+  finally
+    exec 'bwipeout ' .. failed_fname
+  endtry
+enddef
+
+# THE FOLLOWING SETTINGS PERTAIN TO "input/" FILES THAT ARE LIKELY TO BE
+# LOADED SIDE BY SIDE WHENEVER BATCHES OF NEW SCREENDUMPS ARE GENERATED.
+
+# Match "LC_ALL=C" of Makefile.
+language C
+
+# Match the settings from term_util.vim#RunVimInTerminal().
+set t_Co=256 background=light
+hi Normal ctermfg=NONE ctermbg=NONE
+
+# Match the settings from runtest.vim#Xtestscript#SetUpVim().
+set display=lastline ruler scrolloff=5 t_ZH= t_ZR=
+
+# Anticipate non-Latin-1 characters in "input/" files.
+set encoding=utf-8 termencoding=utf-8
+
+autocmd_add([{
+  replace:	true,
+  group:	'viewdumps',
+  event:	'BufRead',
+  pattern:	'*.dump',
+  cmd:		'Render()',
+}])
+
+# Unconditionally help, in case a list of filenames is passed to the command,
+# the first terminal window with its BufRead event.
+silent doautocmd viewdumps BufRead
+
+if error != null_string
+  # Instead of sleeping, fill half a window with blanks and prompt hit-enter.
+  echom error .. repeat("\x20", (winwidth(0) * (winheight(0) / 2) - strlen(error)))
+  error = null_string
+endif
+
+# vim:fdm=syntax:sw=2:ts=8:noet:nolist:nosta: