log: do not segfault on gmtime errors
Many code paths assume that show_date and show_ident_date
cannot return NULL. For the most part, we handle missing or
corrupt timestamps by showing the epoch time t=0.
However, we might still return NULL if gmtime rejects the
time_t we feed it, resulting in a segfault. Let's catch this
case and just format t=0.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/date.c b/date.c
index 2dae471..f64bbeb 100644
--- a/date.c
+++ b/date.c
@@ -184,8 +184,10 @@
tz = local_tzoffset(time);
tm = time_to_tm(time, tz);
- if (!tm)
- return NULL;
+ if (!tm) {
+ tm = time_to_tm(0, 0);
+ tz = 0;
+ }
strbuf_reset(&timebuf);
if (mode == DATE_SHORT)
diff --git a/t/t4212-log-corrupt.sh b/t/t4212-log-corrupt.sh
index 80542d6..85c6df4 100755
--- a/t/t4212-log-corrupt.sh
+++ b/t/t4212-log-corrupt.sh
@@ -76,4 +76,12 @@
test_cmp expect actual
'
+# date is within 2^63-1, but enough to choke glibc's gmtime
+test_expect_success 'absurdly far-in-future dates produce sentinel' '
+ commit=$(munge_author_date HEAD 999999999999999999) &&
+ echo "Thu Jan 1 00:00:00 1970 +0000" >expect &&
+ git log -1 --format=%ad $commit >actual &&
+ test_cmp expect actual
+'
+
test_done
