Bug 77716 Scrollbar is loading asynchronously! - Trunk [@ nsCSSFrameConstructor::ConstructDocElementFrame] [@ .__ptr_glue - nsCSSFrameConstructor::ContentInserted]

patch by hyatt r=jag,dbaron sr=bz, a=dbaron

layout/base/nsCSSFrameConstructor.cpp

@@ -3331,21 +3331,27 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   // ----- reattach gfx scrollbars ------
   // Gfx scrollframes were created in the root frame but the primary frame map may have been destroyed if a 
   // new style sheet was loaded so lets reattach the frames to their content.
-    if (mGfxScrollFrame)
-    {
-        nsIFrame* scrollPort = nsnull;
-        mGfxScrollFrame->FirstChild(aPresContext, nsnull, &scrollPort);
+  if (mGfxScrollFrame) {
+    nsIFrame* scrollPort = nsnull;
+    mGfxScrollFrame->FirstChild(aPresContext, nsnull, &scrollPort);
 
-        nsIFrame* gfxScrollbarFrame1 = nsnull;
-        nsIFrame* gfxScrollbarFrame2 = nsnull;
-        nsresult rv = scrollPort->GetNextSibling(&gfxScrollbarFrame1);
-        rv = gfxScrollbarFrame1->GetNextSibling(&gfxScrollbarFrame2);
-        nsCOMPtr<nsIContent> content;
-        gfxScrollbarFrame1->GetContent(getter_AddRefs(content));
-        aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame1);
+    nsIFrame* gfxScrollbarFrame1 = nsnull;
+    nsIFrame* gfxScrollbarFrame2 = nsnull;
+    nsresult rv = scrollPort->GetNextSibling(&gfxScrollbarFrame1);
+    if (gfxScrollbarFrame1) {
+      nsCOMPtr<nsIContent> content;
+      gfxScrollbarFrame1->GetContent(getter_AddRefs(content));
+      // XXX This works, but why?
+      aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame1);
+
+      rv = gfxScrollbarFrame1->GetNextSibling(&gfxScrollbarFrame2);
+      if (gfxScrollbarFrame2) {
         gfxScrollbarFrame2->GetContent(getter_AddRefs(content));
+        // XXX This works, but why?
         aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame2);
+      }
     }
+  }
 
   // --------- CREATE AREA OR BOX FRAME -------
   nsCOMPtr<nsIStyleContext>  styleContext;

layout/generic/nsGfxScrollFrame.cpp

@@ -1085,7 +1085,7 @@ PRBool
 nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnTop, PRBool aHorizontal, PRBool aAdd)
 {
   if (aHorizontal) {
-     if (mNeverHasHorizontalScrollbar)
+     if (mNeverHasHorizontalScrollbar || !mHScrollbarBox)
        return PR_FALSE;
 
      if (aAdd)
@@ -1106,7 +1106,7 @@ nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScr
 
      return fit;
   } else {
-     if (mNeverHasVerticalScrollbar)
+     if (mNeverHasVerticalScrollbar || !mVScrollbarBox)
        return PR_FALSE;
 
      if (aAdd)
@@ -1646,6 +1646,9 @@ nsGfxScrollFrameInner::GetScrolledSize(nsIPresContext* aPresContext,
 void
 nsGfxScrollFrameInner::SetScrollbarVisibility(nsIBox* aScrollbar, PRBool aVisible)
 {
+  if (!aScrollbar)
+    return;
+
   nsIFrame* frame = nsnull;
   aScrollbar->GetFrame(&frame);
 

layout/html/base/src/nsGfxScrollFrame.cpp

@@ -1085,7 +1085,7 @@ PRBool
 nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnTop, PRBool aHorizontal, PRBool aAdd)
 {
   if (aHorizontal) {
-     if (mNeverHasHorizontalScrollbar)
+     if (mNeverHasHorizontalScrollbar || !mHScrollbarBox)
        return PR_FALSE;
 
      if (aAdd)
@@ -1106,7 +1106,7 @@ nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScr
 
      return fit;
   } else {
-     if (mNeverHasVerticalScrollbar)
+     if (mNeverHasVerticalScrollbar || !mVScrollbarBox)
        return PR_FALSE;
 
      if (aAdd)
@@ -1646,6 +1646,9 @@ nsGfxScrollFrameInner::GetScrolledSize(nsIPresContext* aPresContext,
 void
 nsGfxScrollFrameInner::SetScrollbarVisibility(nsIBox* aScrollbar, PRBool aVisible)
 {
+  if (!aScrollbar)
+    return;
+
   nsIFrame* frame = nsnull;
   aScrollbar->GetFrame(&frame);
 

layout/html/style/src/nsCSSFrameConstructor.cpp

@@ -3331,21 +3331,27 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   // ----- reattach gfx scrollbars ------
   // Gfx scrollframes were created in the root frame but the primary frame map may have been destroyed if a 
   // new style sheet was loaded so lets reattach the frames to their content.
-    if (mGfxScrollFrame)
-    {
-        nsIFrame* scrollPort = nsnull;
-        mGfxScrollFrame->FirstChild(aPresContext, nsnull, &scrollPort);
+  if (mGfxScrollFrame) {
+    nsIFrame* scrollPort = nsnull;
+    mGfxScrollFrame->FirstChild(aPresContext, nsnull, &scrollPort);
 
-        nsIFrame* gfxScrollbarFrame1 = nsnull;
-        nsIFrame* gfxScrollbarFrame2 = nsnull;
-        nsresult rv = scrollPort->GetNextSibling(&gfxScrollbarFrame1);
-        rv = gfxScrollbarFrame1->GetNextSibling(&gfxScrollbarFrame2);
-        nsCOMPtr<nsIContent> content;
-        gfxScrollbarFrame1->GetContent(getter_AddRefs(content));
-        aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame1);
+    nsIFrame* gfxScrollbarFrame1 = nsnull;
+    nsIFrame* gfxScrollbarFrame2 = nsnull;
+    nsresult rv = scrollPort->GetNextSibling(&gfxScrollbarFrame1);
+    if (gfxScrollbarFrame1) {
+      nsCOMPtr<nsIContent> content;
+      gfxScrollbarFrame1->GetContent(getter_AddRefs(content));
+      // XXX This works, but why?
+      aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame1);
+
+      rv = gfxScrollbarFrame1->GetNextSibling(&gfxScrollbarFrame2);
+      if (gfxScrollbarFrame2) {
         gfxScrollbarFrame2->GetContent(getter_AddRefs(content));
+        // XXX This works, but why?
         aState.mFrameManager->SetPrimaryFrameFor(content, gfxScrollbarFrame2);
+      }
     }
+  }
 
   // --------- CREATE AREA OR BOX FRAME -------
   nsCOMPtr<nsIStyleContext>  styleContext;