Prevent git blame from segfaulting on a missing author name

The human-readable author and committer name can be missing from
commits imported from foreign SCM interfaces.  Make sure we parse
the "author" and "committer" line a bit more leniently and avoid
segfaulting by assuming the name always exists.

Signed-off-by: David Reiss <dreiss@facebook.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-blame.c b/builtin-blame.c
index dd16b2229763addfba8f02f3d9b3c42dcb995935..98e818ce6a63b352182b428b49464596d37a0617 100644 (file)
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -1305,6 +1305,7 @@ static void get_ac_line(const char *inbuf, const char *what,
        error_out:
                /* Ugh */
                *tz = "(unknown)";
+               strcpy(person, *tz);
                strcpy(mail, *tz);
                *time = 0;
                return;
@@ -1314,20 +1315,26 @@ static void get_ac_line(const char *inbuf, const char *what,
        tmp = person;
        tmp += len;
        *tmp = 0;
-       while (*tmp != ' ')
+       while (person < tmp && *tmp != ' ')
                tmp--;
+       if (tmp <= person)
+               goto error_out;
        *tz = tmp+1;
        tzlen = (person+len)-(tmp+1);
 
        *tmp = 0;
-       while (*tmp != ' ')
+       while (person < tmp && *tmp != ' ')
                tmp--;
+       if (tmp <= person)
+               goto error_out;
        *time = strtoul(tmp, NULL, 10);
        timepos = tmp;
 
        *tmp = 0;
-       while (*tmp != ' ')
+       while (person < tmp && *tmp != ' ')
                tmp--;
+       if (tmp <= person)
+               return;
        mailpos = tmp + 1;
        *tmp = 0;
        maillen = timepos - tmp;

diff --git a/t/t8003-blame.sh b/t/t8003-blame.sh
index 13c25f1d528ca1ec90575e42e0393accff5d8f35..ad834f200ac0d6ecf532374311d896557a9b941d 100755 (executable)
--- a/t/t8003-blame.sh
+++ b/t/t8003-blame.sh
@@ -144,4 +144,17 @@ test_expect_success 'blame path that used to be a directory' '
        git blame HEAD^.. -- path
 '
 
+test_expect_success 'blame to a commit with no author name' '
+  TREE=`git rev-parse HEAD:`
+  cat >badcommit <<EOF
+tree $TREE
+author <noname> 1234567890 +0000
+committer David Reiss <dreiss@facebook.com> 1234567890 +0000
+
+some message
+EOF
+  COMMIT=`git hash-object -t commit -w badcommit`
+  git --no-pager blame $COMMIT -- uno >/dev/null
+'
+
 test_done