[PATCH] Handle localtime errors in ctime

[Omer Anson <oaanson@gmail.com>]

ctime passes the result from localtime directly to asctime. But in case
of error, localtime returns 0. This causes an error (NULL pointer
dereference) in asctime.

According to the man pages [1], ctime should also return 0 upon error.
Therefore, if localtime fails (return 0), ctime also returns 0.

[1] https://linux.die.net/man/3/ctime
---
 src/time/ctime.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/time/ctime.c b/src/time/ctime.c
index 185ec55..6955f2d 100644
--- a/src/time/ctime.c
+++ b/src/time/ctime.c
@@ -2,5 +2,9 @@
 
 char *ctime(const time_t *t)
 {
-	return asctime(localtime(t));
+	struct tm * tm = localtime(t);
+	if (!tm) {
+		return 0;
+	}
+	return asctime(tm);
 }
-- 
2.4.11