Re: [PATCH] checkpatch: Add check for common mailing list helper checks

[Joe Perches <joe@perches.com>]

On Fri, 2021-07-02 at 15:37 -0700, John 'Warthog9' Hawley (VMware)
wrote:
> From: John 'Warthog9' Hawley <warthog9@eaglescrag.net>
> 
> Mailing lists in an attempt to try and avoid sending certain
> administrative e-mails to the list, will check the first few lines
> (usually ~10) looking for keywords.  If those key words are found it
> shunts the e-mail to the list admin contact instead of potentially
> passing it through to the list.

Perhaps the below is a bit better, but I believe a few of the tests
are going to be tripped a bit too often.

Especially "cancel", "config" and maybe "subscribe" too.

For instance:

$ git log --grep='\bcancel\b' -P -i --pretty=oneline -10000 | wc -l
1693

$ git log --grep='^config\b' -P -i --pretty=oneline -10000 | wc -l
890

$ git log --grep='\bsubscribe\b' -P -i --pretty=oneline -10000 | wc -l
123

---
 scripts/checkpatch.pl | 45 ++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 461d4221e4a4a..fcbcc26da875e 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -865,6 +865,37 @@ our $allowed_asm_includes = qr{(?x:
 )};
 # memory.h: ARM has a custom one
 
+our $mailing_list_phrases = qr{(?xi:
+	\bcancel\b |
+	\badd\s+me\b |
+	\bdelete\s+me\b |
+	\bremove\s+me\b |
+	\bchange\b.*\baddress\b |
+	\bsubscribe\b |
+	^sub\b |
+	\bunsubscribe\b |
+	^unsub\b |
+	^\s*help\s*$ |
+	^\s*info\s*$ |
+	^\s*info\s+\S+\s*$ |
+	^\s*lists\s*$ |
+	^\s*which\s*$ |
+	^\s*which\s+\S+\s*$ |
+	^\s*index\s*$ |
+	^\s*index\s+\S+\s*$ |
+	^\s*who\s*$ |
+	^\s*who\s+\S+\s*$ |
+	^\s*get\s+\S+\s*$ |
+	^\s*get\s+\S+\s+\S+\s*$ |
+	^\s*approve\b |
+	^\s*passwd\b |
+	^\s*newinfo\b |
+	^\s*config\b |
+	^\s*newconfig\b |
+	^\s*writeconfig\b |
+	^\s*mkdigest\b
+)};
+
 # Load common spelling mistakes and build regular expression list.
 my $misspellings;
 my %spelling_fix;
@@ -2581,6 +2612,7 @@ sub process {
 	my $has_patch_separator = 0;	#Found a --- line
 	my $has_commit_log = 0;		#Encountered lines before patch
 	my $commit_log_lines = 0;	#Number of commit log lines
+	my $commit_log_missing = 0;	#Emitted a missing commit message warning
 	my $commit_log_possible_stack_dump = 0;
 	my $commit_log_long_line = 0;
 	my $commit_log_has_diff = 0;
@@ -2852,16 +2884,23 @@ sub process {
 
 		$cnt_lines++ if ($realcnt != 0);
 
+# check if words in the commit message may trip up common mailing list helpers
+# to redirect email to the admin contact
+		if ($in_commit_log && $commit_log_lines < 10 &&
+		    $line =~ /($mailing_list_phrases)/) {
+			WARN("MAILING_LIST_HELPER",
+			     "Line matches common mailing list helpers and may not be delivered correctly - consider rewording '$1'\n" . $herecurr);
+		}
+
 # Verify the existence of a commit log if appropriate
-# 2 is used because a $signature is counted in $commit_log_lines
 		if ($in_commit_log) {
 			if ($line !~ /^\s*$/) {
 				$commit_log_lines++;	#could be a $signature
 			}
-		} elsif ($has_commit_log && $commit_log_lines < 2) {
+		} elsif ($has_commit_log && !$commit_log_missing) {
 			WARN("COMMIT_MESSAGE",
 			     "Missing commit description - Add an appropriate one\n");
-			$commit_log_lines = 2;	#warn only once
+			$commit_log_missing = 1;	#warn only once
 		}
 
 # Check if the commit log has what seems like a diff which can confuse patch