Bug 525751. When using a subdocument frame as a fallback for drawing canvas background color override the canvas frame check. r=roc a=roc

--HG--
extra : rebase_source : 6719372b7404a598a4ce1c1f5190a4f86d0d896b

layout/base/nsIPresShell.h

@@ -122,10 +122,10 @@ typedef struct CapturingContentInfo {
     mAllowed(PR_FALSE), mRetargetToElement(PR_FALSE), mContent(nsnull) { }
 } CapturingContentInfo;
 
-// 7190dd0b-4278-4ad6-bee5-6defef4c5647
-#define NS_IPRESSHELL_IID     \
-{ 0x7190dd0b, 0x4278, 0x4ad6, \
-  { 0xbe, 0xe5, 0x6d, 0xef, 0xef, 0x4c, 0x56, 0x47 } }
+// 4e8724b5-14f9-4bb0-b5a0-24041d653c9f
+ #define NS_IPRESSHELL_IID     \
+{ 0x4e8724b5, 0x14f9, 0x4bb0, \
+  { 0xb5, 0xa0, 0x24, 0x04, 0x1d, 0x65, 0x3c, 0x9f } }
 
 // Constants for ScrollContentIntoView() function
 #define NS_PRESSHELL_SCROLL_TOP      0
@@ -884,15 +884,17 @@ public:
   /**
    * Add a solid color item to the bottom of aList with frame aFrame and
    * bounds aBounds. Checks first if this needs to be done by checking if
-   * aFrame is a canvas frame. If aBounds is null (the default) then the
-   * bounds will be derived from the frame. aBackstopColor is composed behind
-   * the background color of the canvas, it is transparent by default.
+   * aFrame is a canvas frame (if aForceDraw is true then this check is
+   * skipped). If aBounds is null (the default) then the bounds will be derived
+   * from the frame. aBackstopColor is composed behind the background color of
+   * the canvas, it is transparent by default.
    */
   virtual nsresult AddCanvasBackgroundColorItem(nsDisplayListBuilder& aBuilder,
                                                 nsDisplayList& aList,
                                                 nsIFrame* aFrame,
                                                 nsRect* aBounds = nsnull,
-                                                nscolor aBackstopColor = NS_RGBA(0,0,0,0)) = 0;
+                                                nscolor aBackstopColor = NS_RGBA(0,0,0,0),
+                                                PRBool aForceDraw = PR_FALSE) = 0;
 
   void ObserveNativeAnonMutationsForPrint(PRBool aObserve)
   {

layout/base/nsPresShell.cpp

@@ -902,7 +902,8 @@ public:
                                                 nsDisplayList& aList,
                                                 nsIFrame* aFrame,
                                                 nsRect* aBounds,
-                                                nscolor aBackstopColor);
+                                                nscolor aBackstopColor,
+                                                PRBool aForceDraw);
 
 protected:
   virtual ~PresShell();
@@ -5795,7 +5796,8 @@ nsresult PresShell::AddCanvasBackgroundColorItem(nsDisplayListBuilder& aBuilder,
                                                  nsDisplayList&        aList,
                                                  nsIFrame*             aFrame,
                                                  nsRect*               aBounds,
-                                                 nscolor               aBackstopColor)
+                                                 nscolor               aBackstopColor,
+                                                 PRBool                aForceDraw)
 {
   // We don't want to add an item for the canvas background color if the frame
   // (sub)tree we are painting doesn't include any canvas frames. There isn't
@@ -5803,7 +5805,7 @@ nsresult PresShell::AddCanvasBackgroundColorItem(nsDisplayListBuilder& aBuilder,
   // (sub)tree we are painting is a canvas frame that should cover us in all
   // cases (it will usually be a viewport frame when we have a canvas frame in
   // the (sub)tree).
-  if (!nsCSSRendering::IsCanvasFrame(aFrame))
+  if (!aForceDraw && !nsCSSRendering::IsCanvasFrame(aFrame))
     return NS_OK;
 
   nscolor bgcolor = NS_ComposeColors(aBackstopColor, mCanvasBackgroundColor);

layout/generic/nsFrameFrame.cpp

@@ -391,7 +391,8 @@ nsSubDocumentFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   if (!aBuilder->IsForEventDelivery()) {
     // Add the canvas background color.
     rv = presShell->AddCanvasBackgroundColorItem(
-           *aBuilder, childItems, f ? f : this, &shellBounds);
+           *aBuilder, childItems, f ? f : this, &shellBounds, NS_RGBA(0,0,0,0),
+           PR_TRUE);
   }
 
   if (f && NS_SUCCEEDED(rv)) {