Merge 87756

Source/WebCore/dom/Document.cpp

Index: Source/WebCore/dom/Document.cpp
===================================================================
--- Source/WebCore/dom/Document.cpp	(revision 88811)
+++ Source/WebCore/dom/Document.cpp	(working copy)
@@ -443,7 +443,6 @@
     m_ignoreAutofocus = false;
 
     m_frame = frame;
-    m_documentLoader = frame ? frame->loader()->activeDocumentLoader() : 0;
 
     // We depend on the url getting immediately set in subframes, but we
     // also depend on the url NOT getting immediately set in opened windows.
@@ -3733,7 +3732,9 @@
     DateComponents date;
     bool foundDate = false;
     if (m_frame) {
-        String httpLastModified = m_documentLoader->response().httpHeaderField("Last-Modified");
+        String httpLastModified;
+        if (DocumentLoader* documentLoader = loader()) 
+            httpLastModified = documentLoader->response().httpHeaderField("Last-Modified");
         if (!httpLastModified.isEmpty()) {
             date.setMillisecondsSinceEpochForDateTime(parseDate(httpLastModified));
             foundDate = true;
@@ -4441,7 +4442,9 @@
         // load local resources.  See https://bugs.webkit.org/show_bug.cgi?id=16756
         // and https://bugs.webkit.org/show_bug.cgi?id=19760 for further
         // discussion.
-        if (m_documentLoader->substituteData().isValid())
+        
+        DocumentLoader* documentLoader = loader();
+        if (documentLoader && documentLoader->substituteData().isValid())
             securityOrigin()->grantLoadLocalResources();
     }
 
@@ -4522,7 +4525,9 @@
 
     setURL(url);
     f->loader()->setOutgoingReferrer(url);
-    m_documentLoader->replaceRequestURLForSameDocumentNavigation(url);
+
+    if (DocumentLoader* documentLoader = loader())
+        documentLoader->replaceRequestURLForSameDocumentNavigation(url);
 }
 
 void Document::statePopped(SerializedScriptValue* stateObject)
@@ -4988,4 +4993,19 @@
 }
 #endif
 
+DocumentLoader* Document::loader() const
+{
+    if (!m_frame)
+        return 0;
+    
+    DocumentLoader* loader = m_frame->loader()->activeDocumentLoader();
+    if (!loader)
+        return 0;
+    
+    if (m_frame->document() != this)
+        return 0;
+    
+    return loader;
+}
+
 } // namespace WebCore