Re: [PATCH v2] checkpatch: extend author Signed-off-by check for split From: header

[Joe Perches]

On Sun, 2020-09-20 at 14:47 +0530, Dwaipayan Ray wrote:
> Checkpatch did not handle cases where the author From: header
> was split into multiple lines. The author identity could not
> be resolved and checkpatch generated a false NO_AUTHOR_SIGN_OFF
> warning.
> 
> A typical example is Commit e33bcbab16d1 ("tee: add support for
> session's client UUID generation"). When checkpatch was run on
> this commit, it displayed:
> 
> "WARNING:NO_AUTHOR_SIGN_OFF: Missing Signed-off-by: line by nominal
> patch author ''"
> 
> This was due to split header lines not being handled properly and
> the author himself wrote in Commit cd2614967d8b ("checkpatch: warn
> if missing author Signed-off-by"):
> 
> "Split From: headers are not fully handled: only the first part
> is compared."
> 
> Support split From: headers by correctly parsing the header
> extension lines. RFC 2822, Section-2.2.3 stated that each extended
> line must start with a WSP character (a space or htab). The solution
> was therefore to concatenate the lines which start with a WSP to
> get the correct long header.
> 
> Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
> Link: https://lore.kernel.org/linux-kernel-mentees/f5d8124e54a50480b0a9fa638787bc29b6e09854.camel@xxxxxxxxxxx/
> Signed-off-by: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx>

Acked-by: Joe Perches <joe@xxxxxxxxxxx>

> ---
>  scripts/checkpatch.pl | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 504d2e431c60..9e65d21456f1 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2661,6 +2661,10 @@ sub process {
>  # Check the patch for a From:
>  		if (decode("MIME-Header", $line) =~ /^From:\s*(.*)/) {
>  			$author = $1;
> +			my $curline = $linenr;
> +			while(defined($rawlines[$curline]) && ($rawlines[$curline++] =~ /^[ \t]\s*(.*)/)) {
> +				$author .= $1;
> +			}
>  			$author = encode("utf8", $author) if ($line =~ /=\?utf-8\?/i);
>  			$author =~ s/"//g;
>  			$author = reformat_email($author);