Pass back an error when allocating offscreen fails on GTK. bug=70424 r=pavlov@netscape.com, sr=attinasi@netscape.com

gfx/src/gtk/nsDrawingSurfaceGTK.cpp

@@ -265,6 +265,8 @@ NS_IMETHODIMP nsDrawingSurfaceGTK :: Init(GdkDrawable *aDrawable, GdkGC *aGC)
     gdk_image_destroy(mImage);
   mImage = nsnull;
 
+  g_return_val_if_fail(mPixmap != nsnull, NS_ERROR_FAILURE);
+  
   return NS_OK;
 }
 

gfx/src/gtk/nsRenderingContextGTK.cpp

@@ -779,6 +779,7 @@ NS_IMETHODIMP nsRenderingContextGTK::CreateDrawingSurface(nsRect *aBounds,
   g_return_val_if_fail (aBounds != NULL, NS_ERROR_FAILURE);
   g_return_val_if_fail ((aBounds->width > 0) && (aBounds->height > 0), NS_ERROR_FAILURE);
  
+  nsresult rv = NS_OK;
   nsDrawingSurfaceGTK *surf = new nsDrawingSurfaceGTK();
 
   if (surf)
@@ -786,12 +787,14 @@ NS_IMETHODIMP nsRenderingContextGTK::CreateDrawingSurface(nsRect *aBounds,
     NS_ADDREF(surf);
     if (!mGC)
       UpdateGC();
-    surf->Init(mGC, aBounds->width, aBounds->height, aSurfFlags);
+      rv = surf->Init(mGC, aBounds->width, aBounds->height, aSurfFlags);    
+  } else {
+    rv = NS_ERROR_FAILURE;
   }
 
   aSurface = (nsDrawingSurface)surf;
 
-  return NS_OK;
+  return rv;
 }
 
 NS_IMETHODIMP nsRenderingContextGTK::DestroyDrawingSurface(nsDrawingSurface aDS)