Bug 1212954 - Make BaseSize::IsEmpty return true for negative sizes to avoid NS_ERROR in VectorImage::GetFrameAtSize when root svg doesn't have intrinsic width or height. r=roc

gfx/2d/BaseSize.h

@@ -27,7 +27,7 @@ struct BaseSize {
   void SizeTo(T aWidth, T aHeight) { width = aWidth; height = aHeight; }
 
   bool IsEmpty() const {
-    return width == 0 || height == 0;
+    return width <= 0 || height <= 0;
   }
 
   bool IsSquare() const {

image/test/crashtests/1212954-1.svg

@@ -0,0 +1,16 @@
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+
+  <defs>
+    <filter id="f">
+      <!-- the image data is
+           <svg xmlns="http://www.w3.org/2000/svg" width="-5" height="1%" />
+      -->
+      <feImage xlink:href="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSItNSIgaGVpZ2h0
+PSIxJSIgLz4K" />
+    </filter>
+  </defs>
+
+  <rect width="1" height="1" filter="url(#f)" />
+
+</svg>

image/test/crashtests/crashtests.list

@@ -54,6 +54,7 @@ load invalid-disposal-method-2.gif
 load invalid-disposal-method-3.gif
 
 load 1205923-1.html
+load 1212954-1.svg
 
 # Ensure we handle ICO directory entries which specify the wrong size for the
 # contained resource.