commit-graph: avoid using stale stack addresses

The code is a bit too hard to reason about to fully assess whether the `fill_commit_graph_info()` function is called at all after `write_commit_graph()` returns (and hence the stack variable `topo_levels` goes out of context). Let's simply make sure that the stack address is no longer used at that stage, thereby making the code quite a bit easier to reason about. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed May 15, 2025 at 13:11 UTC ee63d026b407118221aca455a9c4f03a08ecf648
1 file changed +9
commit-graph.c
+9
@@ -2683,6 +2683,15 @@ cleanup:
2683 oid_array_clear(&ctx.oids);
2684 clear_topo_level_slab(&topo_levels);
2685
2686 + if (ctx.r->objects->commit_graph) {
2687 + struct commit_graph *g = ctx.r->objects->commit_graph;
2688 +
2689 + while (g) {
2690 + g->topo_levels = NULL;
2691 + g = g->base_graph;
2692 + }
2693 + }
2694 +
2695 for (i = 0; i < ctx.num_commit_graphs_before; i++)
2696 free(ctx.commit_graph_filenames_before[i]);
2697 free(ctx.commit_graph_filenames_before);