Changed the debugger break handling to support situations where there are no ...

src/debug.cc

 // Copyright 2006-2008 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 831 matching lines @@
   // Flood the function with break points.
   BreakLocationIterator it(GetDebugInfo(shared), ALL_BREAK_LOCATIONS);
   while (!it.Done()) {
     it.SetOneShot();
     it.Next();
   }
 }
 
 
 void Debug::FloodHandlerWithOneShot() {
+  // Iterate through the JavaScript stack looking for handlers.
   StackFrame::Id id = Top::break_frame_id();
+  if (id == StackFrame::NO_ID) {
+    // If there is no JavaScript stack don't do anything.
+    return;
+  }
   for (JavaScriptFrameIterator it(id); !it.done(); it.Advance()) {
     JavaScriptFrame* frame = it.frame();
     if (frame->HasHandler()) {
       Handle<SharedFunctionInfo> shared =
           Handle<SharedFunctionInfo>(
               JSFunction::cast(frame->function())->shared());
       // Flood the function with the catch block with break points
       FloodWithOneShot(shared);
       return;
     }
@@ skipping 16 matching lines @@
 
   // Remember this step action and count.
   thread_local_.last_step_action_ = step_action;
   thread_local_.step_count_ = step_count;
 
   // Get the frame where the execution has stopped and skip the debug frame if
   // any. The debug frame will only be present if execution was stopped due to
   // hitting a break point. In other situations (e.g. unhandled exception) the
   // debug frame is not present.
   StackFrame::Id id = Top::break_frame_id();
+  if (id == StackFrame::NO_ID) {
+    // If there is no JavaScript stack don't do anything.
+    return;
+  }
   JavaScriptFrameIterator frames_it(id);
   JavaScriptFrame* frame = frames_it.frame();
 
   // First of all ensure there is one-shot break points in the top handler
   // if any.
   FloodHandlerWithOneShot();
 
   // If the function on the top frame is unresolved perform step out. This will
   // be the case when calling unknown functions and having the debugger stopped
   // in an unhandled exception.
@@ skipping 1053 matching lines @@
 }
 
 
 void LockingMessageQueue::Clear() {
   ScopedLock sl(lock_);
   queue_.Clear();
 }
 
 
 } }  // namespace v8::internal