ref-filter: initialize empty name or email fields

Formatting $(taggername) on headerless tags such as v0.99 in Git
causes a SIGABRT with error "munmap_chunk(): invalid pointer",
because of an oversight in commit f0062d3b74 (ref-filter: free
item->value and item->value->s, 2018-10-19).

Signed-off-by: Mischa POSLAWSKY <git@shiar.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/ref-filter.c b/ref-filter.c
index 5de616befe46e64b014ebe7c3feb5913bc8af2df..3116f742257976686d746d93bcb502aaed7fa46c 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -976,7 +976,7 @@ 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)
@@ -984,10 +984,10 @@ 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);
 }
 

diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 97bfbee6e8d69e46bd1ef1c94dae32d64be977b2..dc1c2e3152d1c90186fb7f271a0b0bc22c271b25 100755 (executable)
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -485,6 +485,25 @@ 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 &&