Fix for 99344, inline styles not being recognized under certain DHTML circumstances. r=dbaron, sr=waterson, a=asa

git-svn-id: svn://10.0.0.236/trunk@118229 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/style/nsStyleSet.cpp

@@ -59,6 +59,7 @@
 #include "nsIHTMLDocument.h"
 #include "nsIDOMHTMLBodyElement.h"
 #include "nsHTMLAtoms.h"
+#include "nsHashtable.h"
 
 #ifdef MOZ_PERF_METRICS
   #include "nsITimeRecorder.h"
@@ -73,6 +74,34 @@
 
 #include "nsISizeOfHandler.h"
 
+// =====================================================
+// nsRuleNodeList
+// A class that represents a chain of rule nodes
+
+struct nsRuleNodeList
+{
+  nsRuleNodeList(nsRuleNode* aRuleNode, nsRuleNodeList* aNext = nsnull)
+    :mRuleNode(aRuleNode), mNext(aNext)
+  {};
+    
+  void* operator new(size_t sz, nsIPresContext* aContext) {
+    void* result = nsnull;
+    aContext->AllocateFromShell(sz, &result);
+    return result;
+  };
+
+  void Destroy() {
+    if (mNext)
+      mNext->Destroy();
+    mRuleNode->PresContext()->FreeToShell(sizeof(nsRuleNodeList), this);
+  };
+
+  nsRuleNode* mRuleNode;
+  nsRuleNodeList* mNext;
+};
+
+// =====================================================
+
 static NS_DEFINE_IID(kIStyleFrameConstructionIID, NS_ISTYLE_FRAME_CONSTRUCTION_IID);
 
 class StyleSetImpl : public nsIStyleSet 
@@ -160,6 +189,8 @@ public:
   
   virtual nsresult GetRuleTree(nsRuleNode** aResult);
   virtual nsresult ClearCachedDataInRuleTree(nsIStyleRule* aRule);
+  
+  virtual nsresult AddRuleNodeMapping(nsRuleNode* aRuleNode);
 
   virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext);
 
@@ -336,6 +367,7 @@ protected:
   nsRuleNode* mOldRuleTree; // Used during rule tree reconstruction.
   nsRuleWalker* mRuleWalker;   // This is an instance of a rule walker that can be used
                                // to navigate through our tree.
+  nsHashtable mRuleMappings; // A hashtable from rules to rule node lists.
 
   MOZ_TIMER_DECLARE(mStyleResolutionWatch)
 
@@ -353,7 +385,8 @@ StyleSetImpl::StyleSetImpl()
     mQuirkStyleSheet(nsnull),
     mRuleTree(nsnull),
     mOldRuleTree(nsnull),
-    mRuleWalker(nsnull)
+    mRuleWalker(nsnull),
+    mRuleMappings(32)
 #ifdef MOZ_PERF_METRICS
     ,mTimerEnabled(PR_FALSE)
 #endif
@@ -1218,9 +1251,19 @@ nsIStyleContext* StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
   return result;
 }
 
+PRBool PR_CALLBACK DeleteRuleNodeLists(nsHashKey* aKey, void* aData, void* aClosure)
+{
+  nsRuleNodeList* ruleNodeList = (nsRuleNodeList*)aData;
+  ruleNodeList->Destroy();
+  return PR_TRUE;
+}
+
 NS_IMETHODIMP
 StyleSetImpl::Shutdown()
 {
+  mRuleMappings.Enumerate(DeleteRuleNodeLists);
+  mRuleMappings.Reset();
+
   delete mRuleWalker;
   if (mRuleTree)
   {
@@ -1237,6 +1280,17 @@ StyleSetImpl::GetRuleTree(nsRuleNode** aResult)
   return NS_OK;
 }
 
+nsresult 
+StyleSetImpl::AddRuleNodeMapping(nsRuleNode* aRuleNode)
+{
+  nsVoidKey key(aRuleNode->Rule());
+  nsRuleNodeList* ruleList = 
+    new (aRuleNode->PresContext()) nsRuleNodeList(aRuleNode, 
+                                                  NS_STATIC_CAST(nsRuleNodeList*, mRuleMappings.Get(&key)));
+  mRuleMappings.Put(&key, ruleList);
+  return NS_OK;
+}
+
 nsresult
 StyleSetImpl::BeginRuleTreeReconstruct()
 {
@@ -1244,6 +1298,8 @@ StyleSetImpl::BeginRuleTreeReconstruct()
   mRuleWalker = nsnull;
   mOldRuleTree = mRuleTree;
   mRuleTree = nsnull;
+  mRuleMappings.Enumerate(DeleteRuleNodeLists);
+  mRuleMappings.Reset();
   return NS_OK;
 }
 
@@ -1274,6 +1330,20 @@ StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule,
   // style.left, we really only need to blow away cached
   // data in the position struct.
   if (aContext) {
+    // |aRule| should never be null, but we'll sanity check it just in case.
+    if (aRule) {
+      // Obtain our rule node list and clear out the cached data in all rule nodes
+      // that correspond to this rule.  See bug 99344 for more details as to how
+      // inline style rules can end up with multiple rule nodes in a rule tree.
+      nsVoidKey key(aRule);
+      nsRuleNodeList* ruleList = NS_STATIC_CAST(nsRuleNodeList*, mRuleMappings.Get(&key));
+      for ( ; ruleList; ruleList = ruleList->mNext)
+        ruleList->mRuleNode->ClearCachedData(aRule);
+    }
+    
+    // XXXdwh I'm just being paranoid here.  Also clear out the data starting at the style
+    // context's rule node.  This really should always be done in the for loop above,
+    // but I'm going to leave this here just in case (for now).
     nsRuleNode* ruleNode;
     aContext->GetRuleNode(&ruleNode);
     ruleNode->ClearCachedData(aRule);