Don't revalidate all resources for FrameLoadTypeSame

Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 713 matching lines @@
     if (request.resourceRequest().cachePolicy() == ReloadBypassingCache)
         return FrameLoadTypeReloadFromOrigin;
     // From the HTML5 spec for location.assign():
     //  "If the browsing context's session history contains only one Document,
     //   and that was the about:blank Document created when the browsing context
     //   was created, then the navigation must be done with replacement enabled."
     if (request.lockBackForwardList()
         || (!m_stateMachine.committedMultipleRealLoads()
             && equalIgnoringCase(m_frame->document()->url(), blankURL())))
         return FrameLoadTypeRedirectWithLockedBackForwardList;
-    if (!request.originDocument() && request.resourceRequest().url() == m_documentLoader->urlForHistory())
-        return FrameLoadTypeSame;
     if (request.substituteData().failingURL() == m_documentLoader->urlForHistory() && m_loadType == FrameLoadTypeReload)
         return FrameLoadTypeReload;
+    if (request.resourceRequest().url() == m_documentLoader->urlForHistory() && request.resourceRequest().httpMethod() != "POST")
+        return FrameLoadTypeRedirectWithLockedBackForwardList;

[dcheng, 2015/07/01 20:54:12]

I don't think I completely understand this line.

1) Can we add a comment about what
FrameLoadTypeRedirectWithLockedBackForwardList is? Or what a locked back/forward
list is?

2) What does this specific case need to map to redirect with locked back/forward
list?

     return FrameLoadTypeStandard;
 }
 
 bool FrameLoader::prepareRequestForThisFrame(FrameLoadRequest& request)
 {
     // If no origin Document* was specified, skip remaining security checks and assume the caller has fully initialized the FrameLoadRequest.
     if (!request.originDocument())
         return true;
 
     KURL url = request.resourceRequest().url();
@@ skipping 130 matching lines @@
         } else {
             request.resourceRequest().setFrameType(WebURLRequest::FrameTypeAuxiliary);
             createWindowForRequest(request, *m_frame, policy, request.shouldSendReferrer());
         }
         return;
     }
 
     const KURL& url = request.resourceRequest().url();
     bool sameDocumentHistoryNavigation =
         isBackForwardLoadType(newLoadType) && historyLoadType == HistorySameDocumentLoad;
-    bool sameDocumentNavigation = policy == NavigationPolicyCurrentTab
-        && shouldPerformFragmentNavigation(
-            request.form(), request.resourceRequest().httpMethod(), newLoadType, url);
+    bool sameDocumentNavigation = policy == NavigationPolicyCurrentTab && shouldPerformFragmentNavigation(request, newLoadType);
 
     // Perform same document navigation.
     if (sameDocumentHistoryNavigation || sameDocumentNavigation) {
         ASSERT(historyItem || !sameDocumentHistoryNavigation);
         RefPtr<SerializedScriptValue> stateObject = sameDocumentHistoryNavigation ?
             historyItem->stateObject() : nullptr;
 
         if (!sameDocumentHistoryNavigation) {
             m_documentLoader->setNavigationType(determineNavigationType(
                 newLoadType, false, request.triggeringEvent()));
             if (shouldTreatURLAsSameAsCurrent(url))
                 newLoadType = FrameLoadTypeRedirectWithLockedBackForwardList;
         }
 
         loadInSameDocument(url, stateObject, newLoadType, request.clientRedirect());
 
         if (sameDocumentHistoryNavigation)
             restoreScrollPositionAndViewState();
         return;
     }
 
-    // Perform navigation to a different document.
-    bool sameURL = url == m_documentLoader->urlForHistory();
     startLoad(request, newLoadType, policy);
-
-    // Example of this case are sites that reload the same URL with a different cookie
-    // driving the generated content, or a master frame with links that drive a target
-    // frame, where the user has clicked on the same link repeatedly.
-    if (sameURL
-        && !isBackForwardLoadType(frameLoadType)
-        && newLoadType != FrameLoadTypeReload
-        && newLoadType != FrameLoadTypeReloadFromOrigin
-        && request.resourceRequest().httpMethod() != "POST") {
-        m_loadType = FrameLoadTypeSame;
-    }
 }
 
 SubstituteData FrameLoader::defaultSubstituteDataForURL(const KURL& url)
 {
     if (!shouldTreatURLAsSrcdocDocument(url))
         return SubstituteData();
     String srcdoc = m_frame->deprecatedLocalOwner()->fastGetAttribute(srcdocAttr);
     ASSERT(!srcdoc.isNull());
     CString encodedSrcdoc = srcdoc.utf8();
     return SubstituteData(SharedBuffer::create(encodedSrcdoc.data(), encodedSrcdoc.length()), "text/html", "UTF-8", KURL());
@@ skipping 256 matching lines @@
         if (m_frame->document()->parser())
             m_frame->document()->parser()->stopParsing();
         if (!m_provisionalDocumentLoader && m_frame->isLoading()) {
             client()->dispatchDidFailLoad(error, historyCommitType);
             m_progressTracker->progressCompleted();
         }
     }
     checkCompleted();
 }
 
-bool FrameLoader::shouldPerformFragmentNavigation(bool isFormSubmission, const String& httpMethod, FrameLoadType loadType, const KURL& url)
+bool FrameLoader::shouldPerformFragmentNavigation(const FrameLoadRequest& request, FrameLoadType loadType)
 {
+    const KURL& url = request.resourceRequest().url();
     // We don't do this if we are submitting a form with method other than "GET", explicitly reloading,
     // currently displaying a frameset, or if the URL does not have a fragment.
-    return (!isFormSubmission || equalIgnoringCase(httpMethod, "GET"))
+    return (!request.form() || equalIgnoringCase(request.resourceRequest().httpMethod(), "GET"))
         && loadType != FrameLoadTypeReload
         && loadType != FrameLoadTypeReloadFromOrigin
-        && loadType != FrameLoadTypeSame
+        && (request.originDocument() || loadType != FrameLoadTypeRedirectWithLockedBackForwardList || url != m_documentLoader->urlForHistory())

[dcheng, 2015/07/01 20:54:12]

I don't think I understand this either. I guess this is sort of covered under
the "explicitly reloading" bits in the comment at line 1190, but I'm not really
sure either. Does that comment need to be updated?

         && loadType != FrameLoadTypeBackForward
         && url.hasFragmentIdentifier()
         && equalIgnoringFragmentIdentifier(m_frame->document()->url(), url)
         // We don't want to just scroll if a link from within a
         // frameset is trying to reload the frameset into _top.
         && !m_frame->document()->isFrameSet();
 }
 
 void FrameLoader::processFragment(const KURL& url, LoadStartType loadStartType)
 {
@@ skipping 266 matching lines @@
     // FIXME: We need a way to propagate insecure requests policy flags to
     // out-of-process frames. For now, we'll always use default behavior.
     if (!parentFrame->isLocalFrame())
         return nullptr;
 
     ASSERT(toLocalFrame(parentFrame)->document());
     return toLocalFrame(parentFrame)->document()->insecureNavigationsToUpgrade();
 }
 
 } // namespace blink