Restore message when rethrowing in TryCatch.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 564fd7b64638694ba978725aa5776995a678f61a..2cb8116070cbf81c0cf51af086ca57f0e46d2c9d 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -107,6 +107,7 @@ void ThreadLocalTop::InitializeInternal() {
   // is complete.
   pending_exception_ = NULL;
   has_pending_message_ = false;
+  rethrowing_message_ = false;
   pending_message_obj_ = NULL;
   pending_message_script_ = NULL;
   scheduled_exception_ = NULL;
@@ -486,7 +487,8 @@ void Isolate::Iterate(ObjectVisitor* v, ThreadLocalTop* thread) {
        block != NULL;
        block = TRY_CATCH_FROM_ADDRESS(block->next_)) {
     v->VisitPointer(BitCast<Object**>(&(block->exception_)));
-    v->VisitPointer(BitCast<Object**>(&(block->message_)));
+    v->VisitPointer(BitCast<Object**>(&(block->message_obj_)));
+    v->VisitPointer(BitCast<Object**>(&(block->message_script_)));
   }
 
   // Iterate over pointers on native execution stack.
@@ -1162,6 +1164,22 @@ void Isolate::ScheduleThrow(Object* exception) {
 }
 
 
+void Isolate::RestorePendingMessageFromTryCatch(v8::TryCatch* handler) {
+  ASSERT(handler == try_catch_handler());
+  ASSERT(handler->HasCaught());
+  ASSERT(handler->rethrow_);
+  ASSERT(handler->capture_message_);
+  Object* message = reinterpret_cast<Object*>(handler->message_obj_);
+  Object* script = reinterpret_cast<Object*>(handler->message_script_);
+  ASSERT(message->IsJSMessageObject() || message->IsTheHole());
+  ASSERT(script->IsScript() || script->IsTheHole());
+  thread_local_top()->pending_message_obj_ = message;
+  thread_local_top()->pending_message_script_ = script;
+  thread_local_top()->pending_message_start_pos_ = handler->message_start_pos_;
+  thread_local_top()->pending_message_end_pos_ = handler->message_end_pos_;
+}
+
+
 Failure* Isolate::PromoteScheduledException() {
   MaybeObject* thrown = scheduled_exception();
   clear_scheduled_exception();
@@ -1280,9 +1298,12 @@ void Isolate::DoThrow(Object* exception, MessageLocation* location) {
       ShouldReportException(&can_be_caught_externally, catchable_by_javascript);
   bool report_exception = catchable_by_javascript && should_report_exception;
   bool try_catch_needs_message =
-      can_be_caught_externally && try_catch_handler()->capture_message_;
+      can_be_caught_externally && try_catch_handler()->capture_message_ &&
+      !thread_local_top()->rethrowing_message_;
   bool bootstrapping = bootstrapper()->IsActive();
 
+  thread_local_top()->rethrowing_message_ = false;
+
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Notify debugger of exception.
   if (catchable_by_javascript) {
@@ -1464,8 +1485,9 @@ void Isolate::ReportPendingMessages() {
         HandleScope scope(this);
         Handle<Object> message_obj(thread_local_top_.pending_message_obj_,
                                    this);
-        if (thread_local_top_.pending_message_script_ != NULL) {
-          Handle<Script> script(thread_local_top_.pending_message_script_);
+        if (!thread_local_top_.pending_message_script_->IsTheHole()) {
+          Handle<Script> script(
+              Script::cast(thread_local_top_.pending_message_script_));
           int start_pos = thread_local_top_.pending_message_start_pos_;
           int end_pos = thread_local_top_.pending_message_end_pos_;
           MessageLocation location(script, start_pos, end_pos);
@@ -1487,8 +1509,9 @@ MessageLocation Isolate::GetMessageLocation() {
       thread_local_top_.pending_exception_ != heap()->termination_exception() &&
       thread_local_top_.has_pending_message_ &&
       !thread_local_top_.pending_message_obj_->IsTheHole() &&
-      thread_local_top_.pending_message_script_ != NULL) {
-    Handle<Script> script(thread_local_top_.pending_message_script_);
+      !thread_local_top_.pending_message_obj_->IsTheHole()) {
+    Handle<Script> script(
+        Script::cast(thread_local_top_.pending_message_script_));
     int start_pos = thread_local_top_.pending_message_start_pos_;
     int end_pos = thread_local_top_.pending_message_end_pos_;
     return MessageLocation(script, start_pos, end_pos);
@@ -2041,15 +2064,24 @@ void Isolate::PropagatePendingExceptionToExternalTryCatch() {
     try_catch_handler()->has_terminated_ = true;
     try_catch_handler()->exception_ = heap()->null_value();
   } else {
+    v8::TryCatch* handler = try_catch_handler();
     // At this point all non-object (failure) exceptions have
     // been dealt with so this shouldn't fail.
     ASSERT(!pending_exception()->IsFailure());
-    try_catch_handler()->can_continue_ = true;
-    try_catch_handler()->has_terminated_ = false;
-    try_catch_handler()->exception_ = pending_exception();
-    if (!thread_local_top_.pending_message_obj_->IsTheHole()) {
-      try_catch_handler()->message_ = thread_local_top_.pending_message_obj_;
-    }
+    ASSERT(thread_local_top_.pending_message_obj_->IsJSMessageObject() ||
+           thread_local_top_.pending_message_obj_->IsTheHole());
+    ASSERT(thread_local_top_.pending_message_script_->IsScript() ||
+           thread_local_top_.pending_message_script_->IsTheHole());
+    handler->can_continue_ = true;
+    handler->has_terminated_ = false;
+    handler->exception_ = pending_exception();
+    // Propagate to the external try-catch only if we got an actual message.
+    if (thread_local_top_.pending_message_obj_->IsTheHole()) return;
+
+    handler->message_obj_ = thread_local_top_.pending_message_obj_;
+    handler->message_script_ = thread_local_top_.pending_message_script_;
+    handler->message_start_pos_ = thread_local_top_.pending_message_start_pos_;
+    handler->message_end_pos_ = thread_local_top_.pending_message_end_pos_;
   }
 }