Re: [PATCH] kdb: Get rid of broken attempt to print CCVERSION in kdb summary

[Joe Perches <joe@perches.com>]

On Fri, 2019-04-19 at 12:28 +0900, Masahiro Yamada wrote:
> Hi Joe,
> 
> Can you detect redundant Cc: by checkpatch?
> 
> Please see below in details.
> Thanks.

Yes, but I'm not sure why it's useful or necessary.
git send-email using some scripts elides duplicate email addresses
---
 scripts/checkpatch.pl | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 1c421ac42b07..bedec83cb797 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2688,6 +2688,19 @@ sub process {
 				$signatures{$sig_nospace} = 1;
 			}
 
+# Check for a cc: line with another signature -by: by the same author
+			if ($sig_nospace =~ /^cc:/) {
+				my $sig_email = substr($sig_nospace, 3);
+				foreach my $sig (sort keys %signatures) {
+					next if ($sig =~ /^cc:/);
+					$sig =~ s/^[^:]+://;
+					if ($sig eq $sig_email) {
+						WARN("BAD_SIGN_OFF",
+						     "Unnecessary CC: as there is another signature with the same name/email address\n" . $herecurr);
+					}
+				}
+			}
+
 # Check Co-developed-by: immediately followed by Signed-off-by: with same name and email
 			if ($sign_off =~ /^co-developed-by:$/i) {
 				if ($email eq $author) {