(svn r14080) -Fix (r14052): assert triggered when drawing chat window with 32bpp-anim blitter (backup buffer was too small)

src/blitter/32bpp_anim.hpp

@@ -34,6 +34,7 @@ public:
 	/* virtual */ Blitter::PaletteAnimation UsePaletteAnimation();
 
 	/* virtual */ const char *GetName() { return "32bpp-anim"; }
+	/* virtual */ int GetBytesPerPixel() { return 5; }
 
 	template <BlitterMode mode> void Draw(const Blitter::BlitterParams *bp, ZoomLevel zoom);
 };