Not mask exception thrown by toString in String::UtfValue etc.

test/cctest/test-api.cc

 // Copyright 2012 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 17460 matching lines @@
   };
 
   i::Semaphore* sem_;
   volatile int sem_value_;
 };
 
 
 THREADED_TEST(SemaphoreInterruption) {
   ThreadInterruptTest().RunTest();
 }
+
+
+TEST(Utf8ValueException) {
+  v8::HandleScope scope;
+  LocalContext context;
+
+  Handle<Value> object = CompileRun(
+      "var obj = { toString : function() { throw 'deadbeef';  } }; obj");
+
+  { v8::TryCatch try_catch;
+    v8::String::Utf8Value utf8_value(object);
+    CHECK(try_catch.HasCaught());
+    CHECK_EQ("deadbeef", *v8::String::Utf8Value(try_catch.Exception()));
+  }
+
+  { v8::TryCatch try_catch;
+    v8::String::AsciiValue ascii_value(object);
+    CHECK(try_catch.HasCaught());
+    CHECK_EQ("deadbeef", *v8::String::Utf8Value(try_catch.Exception()));
+  }
+
+  { v8::TryCatch try_catch;
+    v8::String::Value value(object);
+    CHECK(try_catch.HasCaught());
+    CHECK_EQ("deadbeef", *v8::String::Utf8Value(try_catch.Exception()));
+  }
+
+  // It should work fine without any TryCatch.
+  v8::String::Utf8Value utf8_value(object);
+  v8::String::AsciiValue ascii_value(object);
+  v8::String::Value value(object);
+}
+
 #endif  // WIN32