Commit: runtime(m4): Prevent the m4Disabled region from nesting within itself.

[Christian Brabandt]

runtime(m4): Prevent the m4Disabled region from nesting within itself.

Commit: https://github.com/vim/vim/commit/70d55cd5162b03e5a058907b30bc96d544fc0594
Author: Sam Williams <s...@badcow.co>
Date: Tue Jul 28 18:33:49 2026 +0000

runtime(m4): Prevent the m4Disabled region from nesting within itself.

closes: https://github.com/vim/vim/issues/20801

Signed-off-by: Sam Williams <s...@badcow.co>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/syntax/m4.vim b/runtime/syntax/m4.vim
index c993e5864..95bd0688b 100644
--- a/runtime/syntax/m4.vim
+++ b/runtime/syntax/m4.vim
@@ -46,7 +46,7 @@ syn cluster m4Top add=m4Quoted
" they simply prevent any macros from being expanded, while the text remains
" in the output. This region therefore disables any other matches.
" – Comments themselves are disabled when quoted.
-syn region m4Disabled start=+#+ end=+$+ containedin=ALLBUT,m4Quoted,m4ParamCount
+syn region m4Disabled start=+#+ end=+$+ containedin=ALLBUT,m4Quoted,m4ParamCount,m4Disabled

" Macros in M4:
" – Name tokens consist of the longest possible sequence of letters, digits,
diff --git a/runtime/syntax/testdir/dumps/m4_input_00.dump b/runtime/syntax/testdir/dumps/m4_input_00.dump
new file mode 100644
index 000000000..c8343eb9d
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/m4_input_00.dump
@@ -0,0 +1,20 @@
+>d+0#0000e05#ffffff0|n|l| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |h|i| |d|e|f| |l|i|n|k| |m|4|D|i|s|a|b|l|e|d| |m|4|C|o|m@1|e|n|t| +0#0000000&@23
+@75
+|#+0#0000e05&@39| +0#0000000&@34
+|#+0#0000e05&@1| |<|s|u|m@1|a|r|y|>| +0#0000000&@62
+|#+0#0000e05&@1| @5|D|o|n|t|a|u|d|i|t| |s|e|a|r|c|h| |s@1|h| |h|o|m|e| |d|i|r|e|c|t|o|r|y| +0#0000000&@31
+|#+0#0000e05&@1| |<|/|s|u|m@1|a|r|y|>| +0#0000000&@61
+|#+0#0000e05&@1| |<|p|a|r|a|m| |n|a|m|e|=|"|d|o|m|a|i|n|"|>| +0#0000000&@50
+|#+0#0000e05&@1| @5|<|s|u|m@1|a|r|y|>| +0#0000000&@57
+|#+0#0000e05&@1| @5|D|o|m|a|i|n| |t|o| |n|o|t| |a|u|d|i|t|.| +0#0000000&@46
+|#+0#0000e05&@1| @5|<|/|s|u|m@1|a|r|y|>| +0#0000000&@56
+|#+0#0000e05&@1| |<|/|p|a|r|a|m|>| +0#0000000&@63
+|#+0#0000e05&| +0#0000000&@73
+|i|n|t|e|r|f|a|c|e|(|`+0#e000e06&|s+0#0000000&@1|h|_|d|o|n|t|a|u|d|i|t|_|s|e|a|r|c|h|_|u|s|e|r|_|h|o|m|e|_|d|i|r|'+0#e000e06&|,+0#0000000&|`+0#e000e06&| +0#0000000&@26
+@8|g|e|n|_|r|e|q|u|i|r|e|(+0#e000e06&|`| +0#0000000&@53
+@16|t|y|p|e| |s@1|h|_|h|o|m|e|_|t|;| @42
+@8|'+0#e000e06&|)| +0#0000000&@64
+@75
+@8|d|o|n|t|a|u|d|i|t| |$+0#e000e06&|1| +0#0000000&|s@1|h|_|h|o|m|e|_|t|:|d|i|r| |s|e|a|r|c|h|_|d|i|r|_|p|e|r|m|s|;| @21
+|'+0#e000e06&|)+0#0000000&| @72
+@57|1|,|1| @10|A|l@1|
diff --git a/runtime/syntax/testdir/input/m4_input.m4 b/runtime/syntax/testdir/input/m4_input.m4
new file mode 100644
index 000000000..332cfeeef
--- /dev/null
+++ b/runtime/syntax/testdir/input/m4_input.m4
@@ -0,0 +1,19 @@
+dnl VIM_TEST_SETUP hi def link m4Disabled m4Comment
+
+########################################
+## <summary>
+## Dontaudit search ssh home directory
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain to not audit.
+## </summary>
+## </param>
+#
+interface(`ssh_dontaudit_search_user_home_dir',`
+ gen_require(`
+ type ssh_home_t;
+ ')
+
+ dontaudit $1 ssh_home_t:dir search_dir_perms;
+')