t/helper/test-repository: celebrate independence from the_repository

dade47c06c (commit-graph: add repo arg to graph readers, 2018-07-11) brought more independence from the_repository to the commit graph, however it was not completely independent of the_repository, as the previous patches show. To ensure we're not accessing the_repository by accident, we'd ideally assign NULL to the_repository to trigger a segfault on access. We currently have a temporary hack in cache.h, which relies on the_hash_algo (which is a short form of the_repository->hash_algo) to be set, so we cannot do that. The next best thing is to set all fields of the_repository to 0, so any accidental access is more likely to be found. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Stefan Beller committed Dec 14, 2018 at 16:09 UTC ff509c585e847c5fc40c40d35e7d745dd81363bd
2 files changed +12
cache.h
+2
@@ -1033,6 +1033,8 @@ static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
1033 *
1034 * This will need to be extended or ripped out when we learn about
1035 * hashes of different sizes.
1036 + *
1037 + * When ripping this out, see TODO in test-repository.c.
1038 */
1039 if (the_hash_algo->rawsz != 20)
1040 BUG("hash size not yet supported by hashcmp");
t/helper/test-repository.c
+10
@@ -17,6 +17,11 @@ static void test_parse_commit_in_graph(const char *gitdir, const char *worktree,
17
18 setup_git_env(gitdir);
19
20 + memset(the_repository, 0, sizeof(*the_repository));
21 +
22 + /* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
23 + repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
24 +
25 if (repo_init(&r, gitdir, worktree))
26 die("Couldn't init repo");
27
@@ -43,6 +48,11 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
48
49 setup_git_env(gitdir);
50
51 + memset(the_repository, 0, sizeof(*the_repository));
52 +
53 + /* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
54 + repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
55 +
56 if (repo_init(&r, gitdir, worktree))
57 die("Couldn't init repo");
58