--- cairo-1.2.4/src/cairo-xlib-surface.c
+++ cairo-1.2.4/src/cairo-xlib-surface.c.fix-endianess-mismatch-crasher
@@ -2450,7 +2450,7 @@ _cairo_xlib_surface_add_glyph (Display *
 	    }
 	    n = new;
 	    d = data;
-	    while ((c -= 4) >= 0)
+	    while (c >= 4)
 	    {
 		n[3] = d[0];
 		n[2] = d[1];
@@ -2458,6 +2458,7 @@ _cairo_xlib_surface_add_glyph (Display *
 		n[0] = d[3];
 		d += 4;
 		n += 4;
+		c -= 4;
 	    }
 	    data = new;
 	}