[Linux-kernel-mentees] [PATCH v3] checkpatch: add new exception to repeated word check

[Joe Perches]

On Sat, 2020-10-17 at 11:32 +0530, Dwaipayan Ray wrote:
> > Why include a + character here?
> > 
> Hi,
> I tried it without + first, but then lines like
> "The the repeated word."
> didn't register a warning.
> 
> I think checkpatch adds a + to the line when used on
> files. Am not sure but my $rawline was:
> +The the repeated word.

The + is the first character of an added line in a
patch.

That's different from lines in a commit message so
there needs to be an additional mechanism to strip
the leading + when not !$in_commit_log.

Add:
	pos($rawline) = 1 if (!$in_commit_log);

and test the start position too

---
 scripts/checkpatch.pl | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index fab38b493cef..99563b3d5a3e 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3050,19 +3050,28 @@ sub process {
 
 # check for repeated words separated by a single space
 		if ($rawline =~ /^\+/ || $in_commit_log) {
+			pos($rawline) = 1 if (!$in_commit_log);
 			while ($rawline =~ /\b($word_pattern) (?=($word_pattern))/g) {
-
 				my $first = $1;
 				my $second = $2;
+				my $start_pos = $-[1];
+				my $end_pos = $+[2];
 
 				if ($first =~ /(?:struct|union|enum)/) {
 					pos($rawline) += length($first) + length($second) + 1;
 					next;
 				}
 
-				next if ($first ne $second);
+				next if (lc($first) ne lc($second));
 				next if ($first eq 'long');
 
+				my $start_char = "";
+				my $end_char = "";
+				$start_char = substr($rawline, $start_pos - 1, 1) if ($start_pos > ($in_commit_log ? 0 : 1));
+				$end_char = substr($rawline, $end_pos, 1) if (length($rawline) > $end_pos);
+				next if ($start_char =~ /^\S$/);
+				next if ($end_char !~ /^[\.\,\s]?$/);
+
 				if (WARN("REPEATED_WORD",
 					 "Possible repeated word: '$first'\n" . $herecurr) &&
 				    $fix) {