ass_render: fix potential NULL deref

Fixes CID 146421.

diff --git a/libass/ass_render.c b/libass/ass_render.c
index 88ab7348bd1436a46c6d4419e84db1b354eb5d0c..e7a306000f4beae94e0423a847c7ecccaccb3616 100644 (file)
--- a/libass/ass_render.c
+++ b/libass/ass_render.c
@@ -1803,7 +1803,7 @@ static void make_shadow_bitmap(CombinedBitmapInfo *info, ASS_Renderer *render_pr
     } else if (info->bm_o) {
         info->bm_s = info->bm_o;
         info->bm_o = 0;
-    } else
+    } else if (info->bm)
         info->bm_s = copy_bitmap(render_priv->engine, info->bm);
 
     if (!info->bm_s)