Guard local time posix functions from NaN value of invalid dates.

src/platform-posix.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 68 matching lines @@
 
 int64_t OS::Ticks() {
   // gettimeofday has microsecond resolution.
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0)
     return 0;
   return (static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec;
 }
 
 
-char* OS::LocalTimezone(double time) {
+const char* OS::LocalTimezone(double time) {
+  ASSERT(!isnan(time));
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
-  return const_cast<char*>(t->tm_zone);
+  if (NULL == t) return "";
+  return t->tm_zone;
 }
 
 
 double OS::DaylightSavingsOffset(double time) {
+  ASSERT(!isnan(time));
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
+  if (NULL == t) return nan_value();
   return t->tm_isdst > 0 ? 3600 * msPerSecond : 0;
 }
 
 
 double OS::LocalTimeOffset() {
   time_t tv = time(NULL);
   struct tm* t = localtime(&tv);
   // tm_gmtoff includes any daylight savings offset, so subtract it.
   return static_cast<double>(t->tm_gmtoff * msPerSecond -
                              (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
@@ skipping 245 matching lines @@
   return ntohl(value);
 }
 
 
 Socket* OS::CreateSocket() {
   return new POSIXSocket();
 }
 
 
 } }  // namespace v8::internal