Add method to munge the content state appropriately for how we're matching so that matching operations in HTML and CSS style sheets follow the new rules. (Bug 147777) r=bzbarsky

layout/style/nsCSSRuleProcessor.cpp

@@ -1113,8 +1113,10 @@ RuleProcessorData::ContentState()
       mContentState = mContent->IntrinsicState();
     }
 
-    // If we are not supposed to mark visited links as such, be sure to flip the
+    // If we are not supposed to mark visited links as such, be sure to
-    // bits appropriately.
+    // flip the bits appropriately.  We want to do this here, rather
+    // than in GetContentStateForVisitedHandling, so that we don't
+    // expose that :visited support is disabled to the Web page.
     if ((!gSupportVisitedPseudo ||
         gPrivateBrowsingObserver->InPrivateBrowsing()) &&
         (mContentState & NS_EVENT_STATE_VISITED)) {
@@ -1138,6 +1140,35 @@ RuleProcessorData::IsLink()
   return (state & (NS_EVENT_STATE_VISITED | NS_EVENT_STATE_UNVISITED)) != 0;
 }
 
+PRUint32
+RuleProcessorData::GetContentStateForVisitedHandling(
+                     nsRuleWalker::VisitedHandlingType aVisitedHandling,
+                     PRBool aIsRelevantLink)
+{
+  PRUint32 contentState = ContentState();
+  if (contentState & (NS_EVENT_STATE_VISITED | NS_EVENT_STATE_UNVISITED)) {
+    NS_ABORT_IF_FALSE(IsLink(), "IsLink() should match state");
+    contentState &=
+      ~PRUint32(NS_EVENT_STATE_VISITED | NS_EVENT_STATE_UNVISITED);
+    if (aIsRelevantLink) {
+      switch (aVisitedHandling) {
+        case nsRuleWalker::eRelevantLinkUnvisited:
+          contentState |= NS_EVENT_STATE_UNVISITED;
+          break;
+        case nsRuleWalker::eRelevantLinkVisited:
+          contentState |= NS_EVENT_STATE_VISITED;
+          break;
+        case nsRuleWalker::eLinksVisitedOrUnvisited:
+          contentState |= NS_EVENT_STATE_UNVISITED | NS_EVENT_STATE_VISITED;
+          break;
+      }
+    } else {
+      contentState |= NS_EVENT_STATE_UNVISITED;
+    }
+  }
+  return contentState;
+}
+
 PRInt32
 RuleProcessorData::GetNthIndex(PRBool aIsOfType, PRBool aIsFromEnd,
                                PRBool aCheckEdgeOnly)
@@ -2012,7 +2043,10 @@ static PRBool SelectorMatches(RuleProcessorData &data,
           if (aDependence)
             *aDependence = PR_TRUE;
         } else {
-          if (!(data.ContentState() & statesToCheck)) {
+          PRUint32 contentState = data.GetContentStateForVisitedHandling(
+                                    aTreeMatchContext.mVisitedHandling,
+                                    aNodeMatchContext.mIsRelevantLink);
+          if (!(contentState & statesToCheck)) {
             return PR_FALSE;
           }
         }

layout/style/nsHTMLStyleSheet.cpp

@@ -238,7 +238,11 @@ nsHTMLStyleSheet::RulesMatching(ElementRuleProcessorData* aData)
       // if we have anchor colors, check if this is an anchor with an href
       if (tag == nsGkAtoms::a) {
         if (mLinkRule || mVisitedRule || mActiveRule) {
-          PRUint32 state = aData->ContentState();
+          PRUint32 state = aData->GetContentStateForVisitedHandling(
+                                    ruleWalker->VisitedHandling(),
+                                    // If the node being matched is a link,
+                                    // it's the relevant link.
+                                    aData->IsLink());
           if (mLinkRule && (state & NS_EVENT_STATE_UNVISITED)) {
             ruleWalker->Forward(mLinkRule);
             ruleWalker->SetHaveRelevantLink();

layout/style/nsRuleProcessorData.h

@@ -49,12 +49,12 @@
 #include "nsChangeHint.h"
 #include "nsIContent.h"
 #include "nsCSSPseudoElements.h"
+#include "nsRuleWalker.h"
 
 class nsIStyleSheet;
 class nsPresContext;
 class nsIAtom;
 class nsICSSPseudoComparator;
-class nsRuleWalker;
 class nsAttrValue;
 
 // The implementation of the constructor and destructor are currently in
@@ -111,6 +111,10 @@ public:
   PRUint32 DocumentState();
   PRBool IsLink();
 
+  PRUint32 GetContentStateForVisitedHandling(
+             nsRuleWalker::VisitedHandlingType aVisitedHandling,
+             PRBool aIsRelevantLink);
+
   // Returns a 1-based index of the child in its parent.  If the child
   // is not in its parent's child list (i.e., it is anonymous content),
   // returns 0.
@@ -154,6 +158,8 @@ private:
   // mContentState is initialized lazily.
   PRInt32 mContentState;  // eventStateMgr->GetContentState() or
                           // mContent->IntrinsicState() if we have no ESM
+                          // adjusted for not supporting :visited (but with
+                          // visitedness information when we support it)
   PRPackedBool mGotContentState;
 };