Correct debugger active check

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 1982 matching lines @@
   hack[0] = 0;
   hack[1] = reinterpret_cast<uint32_t>(dispatch) >> 16;
   hack[2] = reinterpret_cast<uint32_t>(dispatch) & 0xFFFF;
   Logger::DebugTag("Put dispatch on command_queue.");
   command_queue_.Put(Vector<uint16_t>(hack, 3).Clone());
   command_received_->Signal();
 }
 
 
 void Debugger::UpdateActiveDebugger() {
-  set_debugger_active((message_thread_ != NULL &&
-                       message_handler_ != NULL) ||
-                       !event_listener_.is_null());
+  set_debugger_active(message_handler_ != NULL || !event_listener_.is_null());
   if (!debugger_active() && message_thread_) {
     // Send an empty command to the debugger if in a break to make JavaScript
     // run again if the debugger is closed.
     ProcessCommand(Vector<const uint16_t>::empty());
   }
   if (!debugger_active()) {
     Debug::Unload();
   }
 }
 
@@ skipping 143 matching lines @@
 }
 
 
 void LockingMessageQueue::Clear() {
   ScopedLock sl(lock_);
   queue_.Clear();
 }
 
 
 } }  // namespace v8::internal