Merge branch 'mp/for-each-ref-missing-name-or-email'

"for-each-ref" and friends that shows refs did not protect themselves
against ancient tags that did not record tagger names when asked to
show "%(taggername)", which have been corrected.

* mp/for-each-ref-missing-name-or-email:
  ref-filter: initialize empty name or email fields

Author: gitster

ref-filter.c

@@ -1028,18 +1028,18 @@ static const char *copy_name(const char *buf)
 		if (!strncmp(cp, " <", 2))
 			return xmemdupz(buf, cp - buf);
 	}
-	return "";
+	return xstrdup("");
 }
 
 static const char *copy_email(const char *buf)
 {
 	const char *email = strchr(buf, '<');
 	const char *eoemail;
 	if (!email)
-		return "";
+		return xstrdup("");
 	eoemail = strchr(email, '>');
 	if (!eoemail)
-		return "";
+		return xstrdup("");
 	return xmemdupz(email, eoemail + 1 - email);
 }
 

t/t6300-for-each-ref.sh

@@ -526,6 +526,25 @@ test_expect_success 'Check ambiguous head and tag refs II (loose)' '
 	test_cmp expected actual
 '
 
+test_expect_success 'create tag without tagger' '
+	git tag -a -m "Broken tag" taggerless &&
+	git tag -f taggerless $(git cat-file tag taggerless |
+		sed -e "/^tagger /d" |
+		git hash-object --stdin -w -t tag)
+'
+
+test_atom refs/tags/taggerless type 'commit'
+test_atom refs/tags/taggerless tag 'taggerless'
+test_atom refs/tags/taggerless tagger ''
+test_atom refs/tags/taggerless taggername ''
+test_atom refs/tags/taggerless taggeremail ''
+test_atom refs/tags/taggerless taggerdate ''
+test_atom refs/tags/taggerless committer ''
+test_atom refs/tags/taggerless committername ''
+test_atom refs/tags/taggerless committeremail ''
+test_atom refs/tags/taggerless committerdate ''
+test_atom refs/tags/taggerless subject 'Broken tag'
+
 test_expect_success 'an unusual tag with an incomplete line' '
 
 	git tag -m "bogo" bogo &&