[129/156] checkpatch: extend author Signed-off-by check for split From: header

Commit Message

Andrew Morton Oct. 16, 2020, 2:49 a.m. UTC

From: Dwaipayan Ray <[e-mail]>
Subject: checkpatch: extend author Signed-off-by check for split From: header

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 5322, 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.

Link: https://lore.kernel.org/linux-kernel-mentees/[e-mail]/
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Dwaipayan Ray <[e-mail]>
Suggested-by: Joe Perches <[e-mail]>
Reviewed-by: Lukas Bulwahn <[e-mail]>
Tested-by: Lukas Bulwahn <[e-mail]>
Acked-by: Joe Perches <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 scripts/checkpatch.pl |    4 ++++
 1 file changed, 4 insertions(+)

Patch

--- a/scripts/checkpatch.pl~checkpatch-extend-author-signed-off-by-check-for-split-from-header
+++ a/scripts/checkpatch.pl
@@ -2679,6 +2679,10 @@  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);