handle errors from localtime_r in ctime_r

POSIX requires ctime_r return a null pointer on failure, which can
occur if the input time_t value is not representable in broken down
form.

based on patch by Alexander Monakov.

diff --git a/src/time/ctime_r.c b/src/time/ctime_r.c
index d2260a1..3e24aa6 100644 (file)
--- a/src/time/ctime_r.c
+++ b/src/time/ctime_r.c
@@ -2,7 +2,6 @@
 
 char *ctime_r(const time_t *t, char *buf)
 {
-       struct tm tm;
-       localtime_r(t, &tm);
-       return asctime_r(&tm, buf);
+       struct tm tm, *tm_p = localtime_r(t, &tm);
+       return tm_p ? asctime_r(tm_p, buf) : 0;
 }