Do not leak message object beyond try-catch.

test/cctest/test-heap.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 5540 matching lines @@
   size_t counter2 = 2000;
   tracer->SampleNewSpaceAllocation(time2, counter2);
   size_t bytes = tracer->NewSpaceAllocatedBytesInLast(1000);
   CHECK_EQ(0, bytes);
   int time3 = 1000;
   size_t counter3 = 30000;
   tracer->SampleNewSpaceAllocation(time3, counter3);
   bytes = tracer->NewSpaceAllocatedBytesInLast(100);
   CHECK_EQ((counter3 - counter1) * 100 / (time3 - time1), bytes);
 }
+
+
+static void CheckLeak(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  Isolate* isolate = CcTest::i_isolate();
+  Object* message =
+      *reinterpret_cast<Object**>(isolate->pending_message_obj_address());
+  CHECK(message->IsTheHole());
+}
+
+
+TEST(MessageObjectLeak) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope scope(isolate);
+  v8::Handle<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
+  global->Set(v8::String::NewFromUtf8(isolate, "check"),
+              v8::FunctionTemplate::New(isolate, CheckLeak));
+  v8::Local<v8::Context> context = v8::Context::New(isolate, NULL, global);
+  v8::Context::Scope cscope(context);
+
+  const char* test =
+      "try {"
+      "  throw 'message';"

[Michael Starzinger, 2015/05/22 13:02:29]

As discussed offline: We should have the same problem with a finally block.
Correct? Consider the following example:

try {
  throw 'message';
} finally {
  break;
}

+      "} catch (e) {"
+      "}"
+      "check();";
+  CompileRun(test);
+
+  FLAG_turbo_filter = "*";
+  FLAG_always_opt = true;
+  FLAG_turbo_exceptions = true;
+
+  CompileRun(test);
+}