Re: [PATCH v1] checkpatch: Warn about sign offs if there's an accidental patch separator

[Kuan-Wei Chiu <visitorckw@gmail.com>]

On Thu, Dec 04, 2025 at 09:34:57PM -0800, Ian Rogers wrote:
> The regex ^---$ to detect a patch separator, means a patch is
> considerd to have been separated only when the line is exactly just
> "---". git-mailinfo (and thus git am) treats any line starting with
> "---" as the start of a patch. This can mean a comment causes
> git-mailinfo to truncate the commit message if the line in the comment
> starts with "---". checkpatch won't warn about things like missing
> sign offs after the "---" started comment as it doesn't see the patch
> as having started yet. The recording of sign offs is made to ignore
> the case it is in a patch. This issue caused missing tags in commit
> 6528cdd61590 ("perf tests stat: Add test for error for an offline CPU")

I guess Namhyung might fix up this commit and force push the branch,
meaning this specific sha id won't exist in Linus' tree later. Given
that, I'm not sure it is appropriate to reference this sha id here?

> as reported by Stephen Rothwell <sfr@canb.auug.org.au> in:
> https://lore.kernel.org/lkml/20251205092428.3e2b94e3@canb.auug.org.au/
> 
> Before:
> 
>   $ ./scripts/checkpatch.pl v2-0006-perf-tests-stat-Add-test-for-error-for-an-offline.patch
>   total: 0 errors, 0 warnings, 39 lines checked
> 
>   v2-0006-perf-tests-stat-Add-test-for-error-for-an-offline.patch has no obvious style problems and is ready for submission.
> 
> After:
> 
>   $ ./scripts/checkpatch.pl v2-0006-perf-tests-stat-Add-test-for-error-for-an-offline.patch
>   ERROR: Missing Signed-off-by: line(s)
> 
>   total: 1 errors, 0 warnings, 39 lines checked
> 
>   NOTE: For some of the reported defects, checkpatch may be able to
>         mechanically convert to the typical style using --fix or --fix-inplace.
> 
>   v2-0006-perf-tests-stat-Add-test-for-error-for-an-offline.patch has style problems, please review.
> 
>   NOTE: If any of the errors are false positives, please report
>         them to the maintainer, see CHECKPATCH in MAINTAINERS.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

FWIW:

Tested-by: Kuan-Wei Chiu <visitorckw@gmail.com>

Regards,
Kuan-Wei

> ---
>  scripts/checkpatch.pl | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 92669904eecc..4fb04162ee56 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2819,6 +2819,11 @@ sub process {
>  			$is_patch = 1;
>  		}
>  
> +# Once the patch separator is encountered git-mailinfo will treat the rest as a patch
> +		if ($has_patch_separator) {
> +			$is_patch = 1;
> +		}
> +
>  #extract the line range in the file after the patch is applied
>  		if (!$in_commit_log &&
>  		    $line =~ /^\@\@ -\d+(?:,\d+)? \+(\d+)(,(\d+))? \@\@(.*)/) {
> @@ -2989,7 +2994,7 @@ sub process {
>  		}
>  
>  # Check the patch for a signoff:
> -		if ($line =~ /^\s*signed-off-by:\s*(.*)/i) {
> +		if (!$is_patch && $line =~ /^\s*signed-off-by:\s*(.*)/i) {
>  			$signoff++;
>  			$in_commit_log = 0;
>  			if ($author ne ''  && $authorsignoff != 1) {
> @@ -3028,7 +3033,7 @@ sub process {
>  		}
>  
>  # Check for patch separator
> -		if ($line =~ /^---$/) {
> +		if ($line =~ /^---/) {
>  			$has_patch_separator = 1;
>  			$in_commit_log = 0;
>  		}
> -- 
> 2.52.0.223.gf5cc29aaa4-goog
> 
>