From 4f33a6345f2bd6e47253d1dbefd01874d895ab2e Mon Sep 17 00:00:00 2001 From: Ævar Arnfjörð Bjarmason Date: Wed, 9 Mar 2022 16:01:38 +0000 Subject: list-objects: handle NULL function pointers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a caller to traverse_commit_list() specifies the options for the --objects flag but does not specify a show_object function pointer, the result is a segfault. This is currently visible by running 'git bundle create --objects HEAD'. We could fix this problem by supplying a no-op callback in builtin/bundle.c, but that only solves the problem for one builtin, leaving this segfault open for other callers. Replace all callers of the show_commit and show_object function pointers in list-objects.c to call helper functions show_commit() and show_object() which check that the given context has non-NULL functions before passing the necessary data. One extra benefit is that it reduces duplication due to passing ctx->show_data to every caller. Test that this segfault no longer occurs for 'git bundle'. Co-authored-by: Derrick Stolee Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano --- list-objects.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) (limited to 'list-objects.c') diff --git a/list-objects.c b/list-objects.c index 117f734398..250d9de41c 100644 --- a/list-objects.c +++ b/list-objects.c @@ -21,6 +21,23 @@ struct traversal_context { struct filter *filter; }; +static void show_commit(struct traversal_context *ctx, + struct commit *commit) +{ + if (!ctx->show_commit) + return; + ctx->show_commit(commit, ctx->show_data); +} + +static void show_object(struct traversal_context *ctx, + struct object *object, + const char *name) +{ + if (!ctx->show_object) + return; + ctx->show_object(object, name, ctx->show_data); +} + static void process_blob(struct traversal_context *ctx, struct blob *blob, struct strbuf *path, @@ -60,7 +77,7 @@ static void process_blob(struct traversal_context *ctx, if (r & LOFR_MARK_SEEN) obj->flags |= SEEN; if (r & LOFR_DO_SHOW) - ctx->show_object(obj, path->buf, ctx->show_data); + show_object(ctx, obj, path->buf); strbuf_setlen(path, pathlen); } @@ -194,7 +211,7 @@ static void process_tree(struct traversal_context *ctx, if (r & LOFR_MARK_SEEN) obj->flags |= SEEN; if (r & LOFR_DO_SHOW) - ctx->show_object(obj, base->buf, ctx->show_data); + show_object(ctx, obj, base->buf); if (base->len) strbuf_addch(base, '/'); @@ -210,7 +227,7 @@ static void process_tree(struct traversal_context *ctx, if (r & LOFR_MARK_SEEN) obj->flags |= SEEN; if (r & LOFR_DO_SHOW) - ctx->show_object(obj, base->buf, ctx->show_data); + show_object(ctx, obj, base->buf); strbuf_setlen(base, baselen); free_tree_buffer(tree); @@ -228,7 +245,7 @@ static void process_tag(struct traversal_context *ctx, if (r & LOFR_MARK_SEEN) tag->object.flags |= SEEN; if (r & LOFR_DO_SHOW) - ctx->show_object(&tag->object, name, ctx->show_data); + show_object(ctx, &tag->object, name); } static void mark_edge_parents_uninteresting(struct commit *commit, @@ -402,7 +419,7 @@ static void do_traverse(struct traversal_context *ctx) if (r & LOFR_MARK_SEEN) commit->object.flags |= SEEN; if (r & LOFR_DO_SHOW) - ctx->show_commit(commit, ctx->show_data); + show_commit(ctx, commit); if (ctx->revs->tree_blobs_in_commit_order) /* -- cgit 1.2.3-korg