Merge 93732

Source/WebKit/mac/Plugins/Hosted/NetscapePluginInstanceProxy.mm

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 673 matching lines @@
     m_pendingFrameLoads.remove(it);
 
     [webFrame _setInternalLoadDelegate:nil];
 }
 
 void NetscapePluginInstanceProxy::evaluateJavaScript(PluginRequest* pluginRequest)
 {
     NSURL *URL = [pluginRequest->request() URL];
     NSString *JSString = [URL _webkit_scriptIfJavaScriptURL];
     ASSERT(JSString);
-    
+
+    RefPtr<NetscapePluginInstanceProxy> protect(this); // Executing arbitrary JavaScript can destroy the proxy.
+
     NSString *result = [[m_pluginView webFrame] _stringByEvaluatingJavaScriptFromString:JSString forceUserGesture:pluginRequest->allowPopups()];
     
     // Don't continue if stringByEvaluatingJavaScriptFromString caused the plug-in to stop.
     if (!m_pluginHostProxy)
         return;
 
     if (pluginRequest->frameName() != nil)
         return;
         
     if ([result length] > 0) {
@@ skipping 969 matching lines @@
         JSLock lock(SilenceAssertionsOnly);
         throwError(exec, createError(exec, stringToUString(globalExceptionString())));
     }
 
     globalExceptionString() = String();
 }
 
 } // namespace WebKit
 
 #endif // USE(PLUGIN_HOST_PROCESS) && ENABLE(NETSCAPE_PLUGIN_API)