From b4007fcc6fe04deeeb3cdf7b018413f65c9de6e8 Mon Sep 17 00:00:00 2001 From: Han-Wen Nienhuys Date: Mon, 21 Feb 2022 18:46:08 +0000 Subject: reftable: ensure that obj_id_len is >= 2 on writing When writing the same hash many times, we might decide to use a length-1 object ID prefix for the ObjectID => ref table, which is out of spec. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano --- reftable/readwrite_test.c | 37 +++++++++++++++++++++++++++++++++++++ reftable/writer.c | 4 +++- 2 files changed, 40 insertions(+), 1 deletion(-) (limited to 'reftable') diff --git a/reftable/readwrite_test.c b/reftable/readwrite_test.c index fd5922e55f..35142eb070 100644 --- a/reftable/readwrite_test.c +++ b/reftable/readwrite_test.c @@ -667,6 +667,42 @@ static void test_write_empty_table(void) strbuf_release(&buf); } +static void test_write_object_id_min_length(void) +{ + struct reftable_write_options opts = { + .block_size = 75, + }; + struct strbuf buf = STRBUF_INIT; + struct reftable_writer *w = + reftable_new_writer(&strbuf_add_void, &buf, &opts); + uint8_t hash[GIT_SHA1_RAWSZ] = {42}; + struct reftable_ref_record ref = { + .update_index = 1, + .value_type = REFTABLE_REF_VAL1, + .value.val1 = hash, + }; + int err; + int i; + + reftable_writer_set_limits(w, 1, 1); + + /* Write the same hash in many refs. If there is only 1 hash, the + * disambiguating prefix is length 0 */ + for (i = 0; i < 256; i++) { + char name[256]; + snprintf(name, sizeof(name), "ref%05d", i); + ref.refname = name; + err = reftable_writer_add_ref(w, &ref); + EXPECT_ERR(err); + } + + err = reftable_writer_close(w); + EXPECT_ERR(err); + EXPECT(writer_stats(w)->object_id_len == 2); + reftable_writer_free(w); + strbuf_release(&buf); +} + static void test_write_empty_key(void) { struct reftable_write_options opts = { 0 }; @@ -772,5 +808,6 @@ int readwrite_test_main(int argc, const char *argv[]) RUN_TEST(test_write_empty_key); RUN_TEST(test_write_empty_table); RUN_TEST(test_log_overflow); + RUN_TEST(test_write_object_id_min_length); return 0; } diff --git a/reftable/writer.c b/reftable/writer.c index d54215a50d..5e4e6e9341 100644 --- a/reftable/writer.c +++ b/reftable/writer.c @@ -515,7 +515,9 @@ static void object_record_free(void *void_arg, void *key) static int writer_dump_object_index(struct reftable_writer *w) { struct write_record_arg closure = { .w = w }; - struct common_prefix_arg common = { NULL }; + struct common_prefix_arg common = { + .max = 1, /* obj_id_len should be >= 2. */ + }; if (w->obj_index_tree) { infix_walk(w->obj_index_tree, &update_common, &common); } -- cgit v1.2.3