diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index 19014098e78..d63888fe7b5 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -106,6 +106,7 @@
 #include "nsIPrintPreviewContext.h"
 #include "nsIDOMMutationEvent.h"
 #include "nsChildIterator.h"
+#include "nsCSSRendering.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -9591,7 +9592,9 @@ SyncAndInvalidateView(nsIPresContext* aPresContext,
   const nsStyleBackground* bg;
   const nsStyleDisplay* disp; 
   const nsStyleVisibility* vis;
-  aFrame->GetStyleData(eStyleStruct_Background, (const nsStyleStruct*&) bg);
+  PRBool isCanvas;
+  PRBool hasBG =
+      nsCSSRendering::FindBackground(aPresContext, aFrame, &bg, &isCanvas);
   aFrame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&) disp);
   aFrame->GetStyleData(eStyleStruct_Visibility, (const nsStyleStruct*&) vis);
 
@@ -9599,8 +9602,10 @@ SyncAndInvalidateView(nsIPresContext* aPresContext,
 
   // See if the view should be hidden or visible
   PRBool  viewIsVisible = PR_TRUE;
-  PRBool  viewHasTransparentContent = (bg->mBackgroundFlags &
-            NS_STYLE_BG_COLOR_TRANSPARENT) == NS_STYLE_BG_COLOR_TRANSPARENT;
+  PRBool  viewHasTransparentContent =
+      !isCanvas &&
+      (!hasBG ||
+       (bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT));
 
   if (NS_STYLE_VISIBILITY_COLLAPSE == vis->mVisible) {
     viewIsVisible = PR_FALSE;
diff --git a/mozilla/layout/base/nsCSSRendering.cpp b/mozilla/layout/base/nsCSSRendering.cpp
index 9529352dd62..46c3c74fdf8 100644
--- a/mozilla/layout/base/nsCSSRendering.cpp
+++ b/mozilla/layout/base/nsCSSRendering.cpp
@@ -2471,7 +2471,8 @@ FindElementBackground(nsIPresContext* aPresContext,
 {
   nsIFrame *parentFrame;
   aForFrame->GetParent(&parentFrame);
-  if (IsCanvasFrame(parentFrame)) {
+  // XXXldb We shouldn't have to null-check |parentFrame| here.
+  if (parentFrame && IsCanvasFrame(parentFrame)) {
     // Check that we're really the root (rather than in another child list).
     nsIFrame *childFrame;
     parentFrame->FirstChild(aPresContext, nsnull, &childFrame);
@@ -2484,7 +2485,7 @@ FindElementBackground(nsIPresContext* aPresContext,
   nsCOMPtr<nsIContent> content;
   aForFrame->GetContent(getter_AddRefs(content));
   nsCOMPtr<nsIDOMHTMLBodyElement> body = do_QueryInterface(content);
-  if (!body)
+  if (!body || !parentFrame)
     return PR_TRUE; // not frame for BODY element
 
   const nsStyleBackground *htmlBG;
diff --git a/mozilla/layout/generic/nsContainerFrame.cpp b/mozilla/layout/generic/nsContainerFrame.cpp
index 659a9cf810d..cedf60d58aa 100644
--- a/mozilla/layout/generic/nsContainerFrame.cpp
+++ b/mozilla/layout/generic/nsContainerFrame.cpp
@@ -60,6 +60,7 @@
 #include "nsIRegion.h"
 #include "nsGfxCIID.h"
 #include "nsIServiceManager.h"
+#include "nsCSSRendering.h"
 
 static NS_DEFINE_CID(kRegionCID, NS_REGION_CID);
 
@@ -513,7 +514,9 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
     const nsStyleBackground* bg;
     const nsStyleVisibility* vis;
     const nsStyleDisplay* display;
-    aFrame->GetStyleData(eStyleStruct_Background, (const nsStyleStruct*&)bg);
+    PRBool isCanvas;
+    PRBool hasBG =
+        nsCSSRendering::FindBackground(aPresContext, aFrame, &bg, &isCanvas);
     aFrame->GetStyleData(eStyleStruct_Visibility, (const nsStyleStruct*&)vis);
     aFrame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
 
@@ -522,8 +525,10 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
 
     // See if the view should be hidden or visible
     PRBool  viewIsVisible = PR_TRUE;
-    PRBool  viewHasTransparentContent = (bg->mBackgroundFlags &
-              NS_STYLE_BG_COLOR_TRANSPARENT) == NS_STYLE_BG_COLOR_TRANSPARENT;
+    PRBool  viewHasTransparentContent =
+        !isCanvas &&
+        (!hasBG ||
+         (bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT));
 
     if (NS_STYLE_VISIBILITY_COLLAPSE == vis->mVisible) {
       viewIsVisible = PR_FALSE;
diff --git a/mozilla/layout/html/base/src/nsContainerFrame.cpp b/mozilla/layout/html/base/src/nsContainerFrame.cpp
index 659a9cf810d..cedf60d58aa 100644
--- a/mozilla/layout/html/base/src/nsContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsContainerFrame.cpp
@@ -60,6 +60,7 @@
 #include "nsIRegion.h"
 #include "nsGfxCIID.h"
 #include "nsIServiceManager.h"
+#include "nsCSSRendering.h"
 
 static NS_DEFINE_CID(kRegionCID, NS_REGION_CID);
 
@@ -513,7 +514,9 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
     const nsStyleBackground* bg;
     const nsStyleVisibility* vis;
     const nsStyleDisplay* display;
-    aFrame->GetStyleData(eStyleStruct_Background, (const nsStyleStruct*&)bg);
+    PRBool isCanvas;
+    PRBool hasBG =
+        nsCSSRendering::FindBackground(aPresContext, aFrame, &bg, &isCanvas);
     aFrame->GetStyleData(eStyleStruct_Visibility, (const nsStyleStruct*&)vis);
     aFrame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
 
@@ -522,8 +525,10 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
 
     // See if the view should be hidden or visible
     PRBool  viewIsVisible = PR_TRUE;
-    PRBool  viewHasTransparentContent = (bg->mBackgroundFlags &
-              NS_STYLE_BG_COLOR_TRANSPARENT) == NS_STYLE_BG_COLOR_TRANSPARENT;
+    PRBool  viewHasTransparentContent =
+        !isCanvas &&
+        (!hasBG ||
+         (bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT));
 
     if (NS_STYLE_VISIBILITY_COLLAPSE == vis->mVisible) {
       viewIsVisible = PR_FALSE;
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
index 19014098e78..d63888fe7b5 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
@@ -106,6 +106,7 @@
 #include "nsIPrintPreviewContext.h"
 #include "nsIDOMMutationEvent.h"
 #include "nsChildIterator.h"
+#include "nsCSSRendering.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -9591,7 +9592,9 @@ SyncAndInvalidateView(nsIPresContext* aPresContext,
   const nsStyleBackground* bg;
   const nsStyleDisplay* disp; 
   const nsStyleVisibility* vis;
-  aFrame->GetStyleData(eStyleStruct_Background, (const nsStyleStruct*&) bg);
+  PRBool isCanvas;
+  PRBool hasBG =
+      nsCSSRendering::FindBackground(aPresContext, aFrame, &bg, &isCanvas);
   aFrame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&) disp);
   aFrame->GetStyleData(eStyleStruct_Visibility, (const nsStyleStruct*&) vis);
 
@@ -9599,8 +9602,10 @@ SyncAndInvalidateView(nsIPresContext* aPresContext,
 
   // See if the view should be hidden or visible
   PRBool  viewIsVisible = PR_TRUE;
-  PRBool  viewHasTransparentContent = (bg->mBackgroundFlags &
-            NS_STYLE_BG_COLOR_TRANSPARENT) == NS_STYLE_BG_COLOR_TRANSPARENT;
+  PRBool  viewHasTransparentContent =
+      !isCanvas &&
+      (!hasBG ||
+       (bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT));
 
   if (NS_STYLE_VISIBILITY_COLLAPSE == vis->mVisible) {
     viewIsVisible = PR_FALSE;
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.cpp b/mozilla/layout/html/style/src/nsCSSRendering.cpp
index 9529352dd62..46c3c74fdf8 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.cpp
+++ b/mozilla/layout/html/style/src/nsCSSRendering.cpp
@@ -2471,7 +2471,8 @@ FindElementBackground(nsIPresContext* aPresContext,
 {
   nsIFrame *parentFrame;
   aForFrame->GetParent(&parentFrame);
-  if (IsCanvasFrame(parentFrame)) {
+  // XXXldb We shouldn't have to null-check |parentFrame| here.
+  if (parentFrame && IsCanvasFrame(parentFrame)) {
     // Check that we're really the root (rather than in another child list).
     nsIFrame *childFrame;
     parentFrame->FirstChild(aPresContext, nsnull, &childFrame);
@@ -2484,7 +2485,7 @@ FindElementBackground(nsIPresContext* aPresContext,
   nsCOMPtr<nsIContent> content;
   aForFrame->GetContent(getter_AddRefs(content));
   nsCOMPtr<nsIDOMHTMLBodyElement> body = do_QueryInterface(content);
-  if (!body)
+  if (!body || !parentFrame)
     return PR_TRUE; // not frame for BODY element
 
   const nsStyleBackground *htmlBG;
diff --git a/mozilla/layout/xul/base/src/nsBoxFrame.cpp b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
index c940d3ba9e4..71f48c68589 100644
--- a/mozilla/layout/xul/base/src/nsBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
@@ -2598,8 +2598,10 @@ nsBoxFrame::CreateViewForFrame(nsIPresContext* aPresContext,
     PRBool  autoZIndex = PR_FALSE;
     PRBool  fixedBackgroundAttachment = PR_FALSE;
 
-    const nsStyleBackground* bg = (const nsStyleBackground*)
-      aStyleContext->GetStyleData(eStyleStruct_Background);
+    const nsStyleBackground* bg;
+    PRBool isCanvas;
+    PRBool hasBG =
+        nsCSSRendering::FindBackground(aPresContext, aFrame, &bg, &isCanvas);
     const nsStyleVisibility* vis = (const nsStyleVisibility*)
       aStyleContext->GetStyleData(eStyleStruct_Visibility);
 
@@ -2611,7 +2613,7 @@ nsBoxFrame::CreateViewForFrame(nsIPresContext* aPresContext,
     }
 
     // See if the frame has a fixed background attachment
-    if (NS_STYLE_BG_ATTACHMENT_FIXED == bg->mBackgroundAttachment) {
+    if (hasBG && NS_STYLE_BG_ATTACHMENT_FIXED == bg->mBackgroundAttachment) {
       aForce = PR_TRUE;
       fixedBackgroundAttachment = PR_TRUE;
     }
@@ -2675,8 +2677,10 @@ nsBoxFrame::CreateViewForFrame(nsIPresContext* aPresContext,
 
         // See if the view should be hidden
         PRBool  viewIsVisible = PR_TRUE;
-        PRBool  viewHasTransparentContent = (bg->mBackgroundFlags &
-                  NS_STYLE_BG_COLOR_TRANSPARENT) == NS_STYLE_BG_COLOR_TRANSPARENT;
+        PRBool  viewHasTransparentContent =
+            !isCanvas &&
+            (!hasBG ||
+             (bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT));
 
         if (NS_STYLE_VISIBILITY_COLLAPSE == vis->mVisible) {
           viewIsVisible = PR_FALSE;