rasterizer: fix pointer arithmetic in assert

path->points can be NULL and any pointer arithmetic
on NULL, even NULL + 0, is undefined behaviour.
The rest of the function should be safe with NULL.

Found by AFL++ and UBSAN.

1 files changed, 1 insertions, 1 deletions

diff --git a/libass/ass_rasterizer.c b/libass/ass_rasterizer.c
index 0ae9e56..36d7883 100644
--- a/libass/ass_rasterizer.c
+++ b/libass/ass_rasterizer.c
@@ -314,7 +314,7 @@ bool rasterizer_set_outline(RasterizerData *rst,
             return false;
         }
     }
-    assert(start == cur && cur == path->points + path->n_points);
+    assert(start == cur && (!cur || cur == path->points + path->n_points));
 
     for (size_t k = rst->n_first; k < rst->size[0]; k++) {
         struct segment *line = &rst->linebuf[0][k];