Fix for bad invalidation/painting when deleting lines of text at the end of a document or mail message. b=86852 r=alexsavulov sr=waterson

layout/generic/nsContainerFrame.cpp

@@ -486,14 +486,16 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
       } else {
         nscoord width, height;
         aView->GetDimensions(&width, &height);
-        // If only the height has changed then repaint only the newly exposed or
+        // If the height and width are unchanged then repaint only the newly exposed or
         // contracted area, otherwise repaint the union of the old and new areas
 
         // XXX:  We currently invalidate the newly exposed areas only when the 
-        // container changes  height because some frames do not invalidate themselves 
-        // properly. see bug 73825.
-        // Once bug 73825 is fixed, we should always pass PR_TRUE instead of frameSize.width == width.
-        vm->ResizeView(aView, frameSize.width, frameSize.height, frameSize.width == width);
+        // container frame dimensions are unchanged changes because some frames do not 
+        // invalidate themselves properly. see bug 73825.
+        // Once bug 73825 is fixed, we should always pass PR_TRUE instead of 
+        // frameSize.width == width && frameSize.height == height.
+        vm->ResizeView(aView, frameSize.width, frameSize.height, 
+                       (frameSize.width == width && frameSize.height == height));
       }
     }
   

layout/html/base/src/nsContainerFrame.cpp

@@ -486,14 +486,16 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
       } else {
         nscoord width, height;
         aView->GetDimensions(&width, &height);
-        // If only the height has changed then repaint only the newly exposed or
+        // If the height and width are unchanged then repaint only the newly exposed or
         // contracted area, otherwise repaint the union of the old and new areas
 
         // XXX:  We currently invalidate the newly exposed areas only when the 
-        // container changes  height because some frames do not invalidate themselves 
-        // properly. see bug 73825.
-        // Once bug 73825 is fixed, we should always pass PR_TRUE instead of frameSize.width == width.
-        vm->ResizeView(aView, frameSize.width, frameSize.height, frameSize.width == width);
+        // container frame dimensions are unchanged changes because some frames do not 
+        // invalidate themselves properly. see bug 73825.
+        // Once bug 73825 is fixed, we should always pass PR_TRUE instead of 
+        // frameSize.width == width && frameSize.height == height.
+        vm->ResizeView(aView, frameSize.width, frameSize.height, 
+                       (frameSize.width == width && frameSize.height == height));
       }
     }