Allow larger passphrase timeout values

This came up in the comp.mail.mutt newsgroup where a user wasn't
satisfied with the SHORT_MAX seconds ~9 hours limit on passphrase
timeouts.

For the first time made it necessary for the options parser to be
able to parse numbers as long values. Also, introduced
mutt_add_timeout() to detect possible overflow before adding a
timeout to a time_t value and truncate to TIME_T_MAX instead.

1 files changed, 13 insertions, 0 deletions

diff --git a/date.c b/date.c
index 2a8d4b47..497ffdd4 100644
--- a/date.c
+++ b/date.c
@@ -120,6 +120,19 @@ time_t mutt_mktime (struct tm *t, int local)
   return (g);
 }
 
+/* Safely add a timeout to a given time_t value, truncating instead of
+ * overflowing. */
+time_t mutt_add_timeout (time_t now, long timeout)
+{
+  if (timeout < 0)
+    return now;
+
+  if (TIME_T_MAX - now < timeout)
+    return TIME_T_MAX;
+
+  return now + timeout;
+}
+
 /* Return 1 if month is February of leap year, else 0 */
 static int isLeapYearFeb (struct tm *tm)
 {