Our "git diff" command supports running as a standalone tool. In this code path, we try to hash the file content but after 18e2588e11 (sha1_file: switch uses of SHA-1 to the_hash_algo - 2018-02-01), there is a chance that the_hash_algo (required by index_path) may still be uninitialized if no repository is found. Executing index_path() when the_hash_algo is NULL (or points to unknown algo) either crashes or dies. Let's make it a bit safer by explicitly falling back to SHA-1 (so that the diff output remains the same as before, compared to the alternative that we simply do not hash). Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx> --- diff.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/diff.c b/diff.c index 21c3838b25..5f28d84b87 100644 --- a/diff.c +++ b/diff.c @@ -3995,6 +3995,18 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o) return; } + /* + * NEEDSWORK: When running in no-index mode (and no repo is + * found, thus no hash algo configured), fall back to SHA-1 + * hashing (which is used by diff_fill_oid_info below) to + * avoid regression in diff output. + * + * In future, perhaps we can allow the user to specify their + * hash algorithm from command line in this mode. + */ + if (o->flags.no_index && !repo_has_valid_hash_algo(the_repository)) + repo_set_hash_algo(the_repository, GIT_HASH_SHA1); + diff_fill_oid_info(one); diff_fill_oid_info(two); -- 2.16.1.435.g8f24da2e1a
