[PATCH v3 07/12] list-objects: handle NULL function pointers
- From
Ævar Arnfjörð Bjarmason via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Mar 8, 2022, 14:39 UTC
- Message-ID
- <782182a26e37eb8e84aef7d8cc67cf276b2abb54.1646750359.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1159.v3.git.1646750359.gitgitgadget@gmail.com>
From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= <avarab@gmail.com>
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 be local methods show_commit() and show_object() which check that the given contex 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 <derrickstolee@github.com> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Derrick Stolee <derrickstolee@github.com> --- bundle.c | 2 ++ list-objects.c | 27 ++++++++++++++++++++++----- t/t6020-bundle-misc.sh | 12 ++++++++++++ 3 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/bundle.c b/bundle.c index a0bb687b0f4..7ba60a573d7 100644 --- a/bundle.c +++ b/bundle.c @@ -544,6 +544,8 @@ int create_bundle(struct repository *r, const char *path, die("revision walk setup failed"); bpi.fd = bundle_fd; bpi.pending = &revs_copy.pending; + + revs.blob_objects = revs.tree_objects = 0; traverse_commit_list(&revs, write_bundle_prerequisites, NULL, &bpi); object_array_remove_duplicates(&revs_copy.pending); diff --git a/list-objects.c b/list-objects.c index 9422625b39e..0af0bef1dbc 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) /* diff --git a/t/t6020-bundle-misc.sh b/t/t6020-bundle-misc.sh index b13e8a52a93..6522401617d 100755 --- a/t/t6020-bundle-misc.sh +++ b/t/t6020-bundle-misc.sh @@ -475,4 +475,16 @@ test_expect_success 'clone from bundle' ' test_cmp expect actual ' +test_expect_success 'unfiltered bundle with --objects' ' + git bundle create all-objects.bdl \ + --all --objects && + git bundle create all.bdl \ + --all && + + # Compare the headers of these files. + head -11 all.bdl >expect && + head -11 all-objects.bdl >actual && + test_cmp expect actual +' + test_done
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