Merge pull request #2058 from cremno/mruby-time-more-portable

mruby-time: two small changes for portability

mrbgems/mruby-time/src/time.c

@@ -86,7 +86,7 @@ gettimeofday(struct timeval *tv, void *tz)
 #endif
 #ifdef NO_GMTIME_R
 #define gmtime_r(t,r) gmtime(t)
-#define localtime_r(t,r) (tzset(),localtime(t))
+#define localtime_r(t,r) localtime(t)
 #endif
 
 #ifndef USE_SYSTEM_TIMEGM
@@ -293,7 +293,7 @@ time_mktime(mrb_state *mrb, mrb_int ayear, mrb_int amonth, mrb_int aday,
   else {
     nowsecs = mktime(&nowtime);
   }
-  if (nowsecs < 0) {
+  if (nowsecs == (time_t)-1) {
     mrb_raise(mrb, E_ARGUMENT_ERROR, "Not a valid time.");
   }