Updated GetTimeZoneName() to return "" if localtime_r fails or has a NULL for its tm_zone value, li…

runtime/vm/os_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/os.h"
 
 #include <errno.h>
 #include <limits.h>
 #include <mach/mach.h>
 #include <mach/clock.h>
@@ skipping 11 matching lines @@
   time_t seconds = static_cast<time_t>(seconds_since_epoch);
   if (seconds != seconds_since_epoch) return false;
   struct tm* error_code = localtime_r(&seconds, tm_result);
   return error_code != NULL;
 }
 
 
 const char* OS::GetTimeZoneName(int64_t seconds_since_epoch) {
   tm decomposed;
   bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
-  ASSERT(succeeded);
-  return decomposed.tm_zone;
+  // If unsuccessful, return an empty string like V8 does.
+  return (succeeded && (decomposed.tm_zone != NULL)) ? decomposed.tm_zone : "";
 }
 
 
 int OS::GetTimeZoneOffsetInSeconds(int64_t seconds_since_epoch) {
   tm decomposed;
   bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
-  ASSERT(succeeded);
   // Even if the offset was 24 hours it would still easily fit into 32 bits.
-  return static_cast<int>(decomposed.tm_gmtoff);
+  // If unsuccessful, return zero like V8 does.
+  return succeeded ? static_cast<int>(decomposed.tm_gmtoff) : 0;
 }
 
 
 int OS::GetLocalTimeZoneAdjustmentInSeconds() {
   // TODO(floitsch): avoid excessive calls to tzset?
   tzset();
   // Even if the offset was 24 hours it would still easily fit into 32 bits.
   // Note that Unix and Dart disagree on the sign.
   return static_cast<int>(-timezone);
 }
@@ skipping 128 matching lines @@
 void OS::Abort() {
   abort();
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart