From f6e7d66b9f1db07ae80af3d75dabaf95f7f43a15 Mon Sep 17 00:00:00 2001
From: Douglas Christman <DouglasChristman@gmail.com>
Date: Tue, 22 Nov 2016 12:57:07 -0500
Subject: [PATCH] calendarspec: add upper bound on year

Stop looking for matches after MAX_YEAR so impossible dates like
"*-02-30" and "*-04-31" don't cause an infinite loop.
---
 src/basic/calendarspec.c     | 12 +++++++++++-
 src/test/test-calendarspec.c |  1 +
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/basic/calendarspec.c b/src/basic/calendarspec.c
index fda293fcb9..2fc5ceb421 100644
--- a/src/basic/calendarspec.c
+++ b/src/basic/calendarspec.c
@@ -34,6 +34,8 @@
 
 /* Longest valid date/time range is 1970..2199 */
 #define MAX_RANGE_LEN   230
+#define MIN_YEAR       1970
+#define MAX_YEAR       2199
 #define BITS_WEEKDAYS   127
 
 static void free_chain(CalendarComponent *c) {
@@ -169,7 +171,7 @@ _pure_ bool calendar_spec_valid(CalendarSpec *c) {
         if (c->weekdays_bits > BITS_WEEKDAYS)
                 return false;
 
-        if (!chain_valid(c->year, 1970, 2199))
+        if (!chain_valid(c->year, MIN_YEAR, MAX_YEAR))
                 return false;
 
         if (!chain_valid(c->month, 1, 12))
@@ -1017,6 +1019,14 @@ static bool tm_out_of_bounds(const struct tm *tm, bool utc) {
         if (mktime_or_timegm(&t, utc) == (time_t) -1)
                 return true;
 
+        /*
+         * Set an upper bound on the year so impossible dates like "*-02-31"
+         * don't cause find_next() to loop forever. tm_year contains years
+         * since 1900, so adjust it accordingly.
+         */
+        if (tm->tm_year + 1900 > MAX_YEAR)
+                return true;
+
         /* Did any normalization take place? If so, it was out of bounds before */
         return
                 t.tm_year != tm->tm_year ||
diff --git a/src/test/test-calendarspec.c b/src/test/test-calendarspec.c
index 59217b131c..18e46f2ac4 100644
--- a/src/test/test-calendarspec.c
+++ b/src/test/test-calendarspec.c
@@ -190,6 +190,7 @@ int main(int argc, char* argv[]) {
         test_next("2015-11-13 09:11:23.42/1.77", "EET", 1447398683420000, 1447398685190000);
         test_next("2015-11-13 09:11:23.42/1.77", "EET", 1447398683419999, 1447398683420000);
         test_next("Sun 16:00:00", "CET", 1456041600123456, 1456066800000000);
+        test_next("*-04-31", "", 12345, -1);
 
         assert_se(calendar_spec_from_string("test", &c) < 0);
         assert_se(calendar_spec_from_string("", &c) < 0);