[libvirt] [PATCH hooks 1/1] Add check for Signed-off-by in commit messages

[Daniel P. Berrange]

This extends the update hook so that it enforces a requirement to have a
Signed-off-by line in every commit message. This can be optionally
turned off in individual repos by setting the "hooks.allowmissingsob"
git config variable.

Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
 update | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/update b/update
index 6a8edcb..b7cfe7f 100755
--- a/update
+++ b/update
@@ -248,7 +248,21 @@ if [ $check_diff = yes ]; then
 	if [ "$allow_bad_whitespace" != "true" ]; then
 		test "$oldrev" = $zero \
 			&& exit 0
-		exec git diff --check $oldrev $newrev --
+		git diff --check $oldrev $newrev --
+		test $? != 0 && exit 1
+	fi
+
+	allow_missing_sob=$(git config --bool hooks.allowmissingsob)
+	if [ "$allow_missing_sob" != "true" ]; then
+		for rev in `git log --format=%h $oldrev..$newrev`
+		do
+			git show $rev | grep Signed-off-by >/dev/null 2>&1
+			if test $? != 0
+			then
+				echo "*** Update hook: missing Signed-off-by tag in $rev" >&2
+				exit 1
+			fi
+		done
 	fi
 fi
 
-- 
2.14.3