Merge 88489 - 2011-06-09 Kenneth Russell <kbr@google.com>

Source/WebCore/html/canvas/CanvasRenderingContext.cpp

 /*
  * Copyright (C) 2009 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 23 matching lines @@
 #include "KURL.h"
 #include "SecurityOrigin.h"
 
 namespace WebCore {
 
 CanvasRenderingContext::CanvasRenderingContext(HTMLCanvasElement* canvas)
     : m_canvas(canvas)
 {
 }
 
-void CanvasRenderingContext::checkOrigin(const CanvasPattern* pattern)
+bool CanvasRenderingContext::wouldTaintOrigin(const CanvasPattern* pattern)
 {
     if (canvas()->originClean() && pattern && !pattern->originClean())
-        canvas()->setOriginTainted();
+        return true;
+    return false;
 }
 
-void CanvasRenderingContext::checkOrigin(const HTMLCanvasElement* sourceCanvas)
+bool CanvasRenderingContext::wouldTaintOrigin(const HTMLCanvasElement* sourceCanvas)
 {
     if (canvas()->originClean() && sourceCanvas && !sourceCanvas->originClean())
-        canvas()->setOriginTainted();
+        return true;
+    return false;
 }
 
-void CanvasRenderingContext::checkOrigin(const HTMLImageElement* image)
+bool CanvasRenderingContext::wouldTaintOrigin(const HTMLImageElement* image)
 {
     if (!image || !canvas()->originClean())
-        return;
+        return false;
 
     CachedImage* cachedImage = image->cachedImage();
-    if (!cachedImage->passesAccessControlCheck(canvas()->securityOrigin()))
-        checkOrigin(cachedImage->response().url());
+    if (!cachedImage->passesAccessControlCheck(canvas()->securityOrigin())) {
+        if (wouldTaintOrigin(cachedImage->response().url()))
+            return true;
+    }
 
-    if (canvas()->originClean() && !cachedImage->image()->hasSingleSecurityOrigin())
-        canvas()->setOriginTainted();
+    if (!cachedImage->image()->hasSingleSecurityOrigin())
+        return true;
+
+    return false;
 }
 
-void CanvasRenderingContext::checkOrigin(const HTMLVideoElement* video)
+bool CanvasRenderingContext::wouldTaintOrigin(const HTMLVideoElement* video)
 {
 #if ENABLE(VIDEO)
     // FIXME: This check is likely wrong when a redirect is involved. We need
     // to test the finalURL. Please be careful when fixing this issue not to
     // make currentSrc be the final URL because then the
     // HTMLMediaElement.currentSrc DOM API would leak redirect destinations!
-    checkOrigin(video->currentSrc());
-    if (canvas()->originClean() && video && !video->hasSingleSecurityOrigin())
-        canvas()->setOriginTainted();
+    if (!video || !canvas()->originClean())
+        return false;
+
+    if (wouldTaintOrigin(video->currentSrc()))
+        return true;
+
+    if (!video->hasSingleSecurityOrigin())
+        return true;
 #endif
+
+    return false;
+}
+
+bool CanvasRenderingContext::wouldTaintOrigin(const KURL& url)
+{
+    if (!canvas()->originClean() || m_cleanURLs.contains(url.string()))
+        return false;
+
+    if (canvas()->securityOrigin()->taintsCanvas(url))
+        return true;
+
+    m_cleanURLs.add(url.string());
+    return false;
 }
 
 void CanvasRenderingContext::checkOrigin(const KURL& url)
 {
-    if (!canvas()->originClean() || m_cleanOrigins.contains(url.string()))
-        return;
-
-    if (canvas()->securityOrigin()->taintsCanvas(url))
+    if (wouldTaintOrigin(url))
         canvas()->setOriginTainted();
-    else
-        m_cleanOrigins.add(url.string());
 }
 
 } // namespace WebCore