Elimninate the last known source of bogus "wrong parent style context" warnings, and make these warnings into assertions. Bug 374297, r+sr+a=dbaron

layout/base/nsCSSFrameConstructor.cpp

@@ -9923,23 +9923,13 @@ nsCSSFrameConstructor::ProcessRestyledFrames(nsStyleChangeList& aChangeList)
           viewMgr->SynthesizeMouseMove(PR_FALSE);
       }
     }
-
-#ifdef DEBUG
-    // reget from content since it may have been regenerated...
-    if (content) {
-      nsIFrame* frame = mPresShell->GetPrimaryFrameFor(content);
-      if (frame) {
-        mPresShell->FrameManager()->DebugVerifyStyleTree(frame);
-      }
-    } else {
-      NS_WARNING("Unable to test style tree integrity -- no content node");
-    }
-#endif
   }
 
   EndUpdate();
   
-  // cleanup references
+  // cleanup references and verify the style tree.  Note that the latter needs
+  // to happen once we've processed the whole list, since until then the tree
+  // is not in fact in a consistent state.
   index = count;
   while (0 <= --index) {
     const nsStyleChangeData* changeData;
@@ -9948,6 +9938,18 @@ nsCSSFrameConstructor::ProcessRestyledFrames(nsStyleChangeList& aChangeList)
       propTable->DeleteProperty(changeData->mFrame,
                                 nsGkAtoms::changeListProperty);
     }
+
+#ifdef DEBUG
+    // reget frame from content since it may have been regenerated...
+    if (changeData->mContent) {
+      nsIFrame* frame = mPresShell->GetPrimaryFrameFor(changeData->mContent);
+      if (frame) {
+        mPresShell->FrameManager()->DebugVerifyStyleTree(frame);
+      }
+    } else {
+      NS_WARNING("Unable to test style tree integrity -- no content node");
+    }
+#endif
   }
 
   aChangeList.Clear();

layout/base/nsFrameManager.cpp

@@ -777,8 +777,8 @@ VerifySameTree(nsStyleContext* aContext1, nsStyleContext* aContext2)
       break;
     top2 = parent;
   }
-  if (top1 != top2)
-    printf("Style contexts are not in the same style context tree.\n");
+  NS_ASSERTION(top1 == top2,
+               "Style contexts are not in the same style context tree");
 }
 
 static void
@@ -812,9 +812,10 @@ VerifyContextParent(nsPresContext* aPresContext, nsIFrame* aFrame,
     if (aParentContext != actualParentContext) {
       DumpContext(aFrame, aContext);
       if (aContext == aParentContext) {
-        fputs("Using parent's style context\n\n", stdout);
+        NS_ERROR("Using parent's style context");
       }
       else {
+        NS_ERROR("Wrong parent style context");
         fputs("Wrong parent style context: ", stdout);
         DumpContext(nsnull, actualParentContext);
         fputs("should be using: ", stdout);
@@ -826,6 +827,7 @@ VerifyContextParent(nsPresContext* aPresContext, nsIFrame* aFrame,
   }
   else {
     if (actualParentContext) {
+      NS_ERROR("Have parent context and shouldn't");
       DumpContext(aFrame, aContext);
       fputs("Has parent context: ", stdout);
       DumpContext(nsnull, actualParentContext);