Fix crash in ScriptDebugServer::wrapCallFrames

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 5e862874a15626056f67b8686ed5cf5df1279319..708f57712326603702a239c277befd363b536173 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1029,9 +1029,13 @@ void Isolate::DoThrow(Object* exception, MessageLocation* location) {
 
   thread_local_top()->rethrowing_message_ = false;
 
-  // Notify debugger of exception.
+  // Notify debugger of exception. Temporarily clear any scheduled_exception
+  // to allow evaluating JavaScript from the debug event handler.
   if (catchable_by_javascript) {
+    Object* saved_scheduled_exception = scheduled_exception();
+    clear_scheduled_exception();

[Yang, 2014/09/10 14:46:13]

Can we put this into OnThrow?

[aandrey, 2014/09/11 05:48:29]

Done.

     debug()->OnThrow(exception_handle, report_exception);
+    thread_local_top()->scheduled_exception_ = saved_scheduled_exception;
   }
 
   // Generate the message if required.