Correctly handle uncaught exception objects.

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 41eb68f231f24d1f5fdc9eff1211429e8efa206e..ec7379c468f7a31a01c46dfa311ad8e9779bdcb0 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -2554,6 +2554,18 @@ THREADED_TEST(ScriptException) {
 }
 
 
+TEST(TryCatchCustomException) {
+  v8::HandleScope scope;
+  LocalContext env;
+  v8::TryCatch try_catch;
+  CompileRun("function CustomError() { this.a = 'b'; }"
+             "(function f() { throw new CustomError(); })();");
+  CHECK(try_catch.HasCaught());
+  CHECK(try_catch.Exception()->ToObject()->
+            Get(v8_str("a"))->Equals(v8_str("b")));
+}
+
+
 bool message_received;