Check that function being patched has no activations on any thread stack

src/liveedit.cc

 // Copyright 2010 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 302 matching lines @@
   int current_parent_index_;
 };
 
 static FunctionInfoListener* active_function_info_listener = NULL;
 
 JSArray* LiveEdit::GatherCompileInfo(Handle<Script> script,
                                      Handle<String> source) {
   CompilationZoneScope zone_scope(DELETE_ON_EXIT);
 
   FunctionInfoListener listener;
+  Handle<Object> original_source = Handle<Object>(script->source());
   script->set_source(*source);
   active_function_info_listener = &listener;
-  Handle<Object> original_source = Handle<Object>(script->source());
   CompileScriptForTracker(script);
   active_function_info_listener = NULL;
   script->set_source(*original_source);
 
   return *(listener.GetResult());
 }
 
 
 void LiveEdit::WrapSharedFunctionInfos(Handle<JSArray> array) {
   HandleScope scope;
@@ skipping 138 matching lines @@
 
 bool LiveEditFunctionTracker::IsActive() {
   return false;
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 
 } }  // namespace v8::internal