Merge pull request #3 from yangfasheng/master

R6 使用中已知 BUG 修复；

cairo-1.14.12/src/cairo-surface-snapshot-inline.h

@@ -61,7 +61,8 @@ _cairo_surface_snapshot_get_target (cairo_surface_t *surface)
 static inline cairo_bool_t
 _cairo_surface_is_snapshot (cairo_surface_t *surface)
 {
-    return surface->backend->type == (cairo_surface_type_t)CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT;
+    //return surface->backend->type == (cairo_surface_type_t)CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT;
+	return surface->backend->type == CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT;	// for R6 GCC < XY >
 }
 
 #endif /* CAIRO_SURFACE_SNAPSHOT_INLINE_H */