return error when first tile references a non-existing image (#1472)

farindk · farindk · commit 7a3383fcd47d · 2025-02-28T15:48:05.000+01:00
diff --git a/libheif/image-items/grid.cc b/libheif/image-items/grid.cc
@@ -539,7 +539,7 @@ heif_image_tiling ImageItem_Grid::get_heif_image_tiling() const
   if (!tile_ids.empty() && tile_ids[0] != 0) {
     heif_item_id tile0_id = tile_ids[0];
     auto tile0 = get_context()->get_image(tile0_id, true);
-    if (tile0->get_item_error()) {
+    if (tile0 == nullptr || tile0->get_item_error()) {
       return tiling;
     }
 

Original file line number	Diff line number	Diff line change
`@@ -539,7 +539,7 @@ heif_image_tiling ImageItem_Grid::get_heif_image_tiling() const`
`539`	`539`	`if (!tile_ids.empty() && tile_ids[0] != 0) {`
`540`	`540`	`heif_item_id tile0_id = tile_ids[0];`
`541`	`541`	`auto tile0 = get_context()->get_image(tile0_id, true);`
`542`		`- if (tile0->get_item_error()) {`
	`542`	`+ if (tile0 == nullptr \|\| tile0->get_item_error()) {`
`543`	`543`	`return tiling;`
`544`	`544`	`}`
`545`	`545`