[PATCH] maint: ensure "Co-authored-by" in commit message has an email address

[Bernhard Voelker]

Otherwise, the script "gitlog-to-changelog" would issue a warning
during 'make dist':

  ./build-aux/gitlog-to-changelog  --since=2008-02-08 > /dev/null
  gitlog-to-changelog: warning: missing email address for Bernhard \
  Voelker.
  gitlog-to-changelog: warning: missing email address for Niels Möller

* scripts/git-hooks/commit-msg: Add a check if a "Co-authored-by:"
line has an email address.
---
 scripts/git-hooks/commit-msg | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/scripts/git-hooks/commit-msg b/scripts/git-hooks/commit-msg
index 559a0ea..4bd038a 100755
--- a/scripts/git-hooks/commit-msg
+++ b/scripts/git-hooks/commit-msg
@@ -133,6 +133,13 @@ sub check_msg($$)
   $buf =~ /^ *Signed-off-by:/mi
     and return q(do not use "Signed-off-by:");
 
+  if ($buf =~ /^Co-authored-by:/mi)
+    {
+      # Ensure gitlog-to-changelog finds the email address in "Co-authored-by".
+      $buf =~ /^Co-authored-by:.*<.*?@.*\..*>/mi
+        or return q(use email address in "Co-authored-by:");
+    }
+
   return '';
 }
 
-- 
1.8.4.5