Fix bug 292914: if scrolling up more than 32767 pixels, window didn't refresh. Fix by just manually invalidating if scrolling will redraw the entire scrolled area. r=joshmoz, sr=jhpedemonte, a=bsmedberg.

widget/src/mac/nsWindow.cpp

@@ -1744,20 +1744,19 @@ nsWindow::ScrollBits ( Rect & inRectToScroll, PRInt32 inLeftDelta, PRInt32 inTop
 //-------------------------------------------------------------------------
 NS_IMETHODIMP nsWindow::Scroll(PRInt32 aDx, PRInt32 aDy, nsRect *aClipRect)
 {
-
-  
-  if (mVisible && ContainerHierarchyIsVisible())  {
-    nsRect scrollRect;	
-
+  if (mVisible && ContainerHierarchyIsVisible())
+  {
     // If the clipping region is non-rectangular, just force a full update, sorry.
     // XXX ?
-	  if (!IsRegionRectangular(mWindowRegion)) {
+    if (!IsRegionRectangular(mWindowRegion))
+    {
       Invalidate(PR_TRUE);
       goto scrollChildren;
     }
 
     //--------
     // Scroll this widget
+    nsRect scrollRect;  
     if (aClipRect)
       scrollRect = *aClipRect;
     else
@@ -1766,10 +1765,17 @@ NS_IMETHODIMP nsWindow::Scroll(PRInt32 aDx, PRInt32 aDy, nsRect *aClipRect)
       scrollRect.x = scrollRect.y = 0;
     }
 
+    // If we're scrolling by an amount that is larger than the height or
+    // width, just invalidate the entire area.
+    if (aDx >= scrollRect.width || aDy >= scrollRect.height)
+    {
+      Invalidate(scrollRect, PR_TRUE);
+    }
+    else
+    {
       Rect macRect;
       nsRectToMacRect(scrollRect, macRect);
 
-
       StartDraw();
 
       // Clip to the windowRegion instead of the visRegion (note: the visRegion
@@ -1782,6 +1788,7 @@ NS_IMETHODIMP nsWindow::Scroll(PRInt32 aDx, PRInt32 aDy, nsRect *aClipRect)
 
       EndDraw();
     }
+  }
 
 scrollChildren:
   //--------