builtin/init-db: add environment variable for new repo hash

For the foreseeable future, SHA-1 will be the default algorithm for Git. However, when running the testsuite, we want to be able to test an arbitrary algorithm. It would be quite burdensome and very untidy to have to specify the algorithm we'd like to test every time we initialized a new repository somewhere in the testsuite, so add an environment variable to allow us to specify the default hash algorithm for Git. This has the benefit that we can set it once for the entire testsuite and not have to think about it. In the future, users can also use it to set the default for their repositories if they would like to do so. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

brian m. carlson committed Feb 22, 2020 at 20:17 UTC 3c9331a12980bb897ba4da24789bf36b18222f4f

2 files changed +15

Documentation/git.txt

@@ -493,6 +493,12 @@ double-quotes and respecting backslash escapes. E.g., the value

493 details. This variable has lower precedence than other path

494 variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...

495

496 +`GIT_DEFAULT_HASH_ALGORITHM`::

497 + If this variable is set, the default hash algorithm for new

498 + repositories will be set to this value. This value is currently

499 + ignored when cloning; the setting of the remote repository

500 + is used instead. The default is "sha1".

501 +

502 Git Commits

503 ~~~~~~~~~~~

504 `GIT_AUTHOR_NAME`::

builtin/init-db.c

@@ -20,6 +20,8 @@

20 #define TEST_FILEMODE 1

21 #endif

23 +#define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"

24 +

25 static int init_is_bare_repository = 0;

26 static int init_shared_repository = -1;

27 static const char *init_db_template_dir;

@@ -356,6 +358,7 @@ static void separate_git_dir(const char *git_dir, const char *git_link)

358

359 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)

360 {

361 + const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);

362 /*

363 * If we already have an initialized repo, don't allow the user to

364 * specify a different algorithm, as that could cause corruption.

@@ -365,6 +368,12 @@ static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash

368 die(_("attempt to reinitialize repository with different hash"));

369 else if (hash != GIT_HASH_UNKNOWN)

370 repo_fmt->hash_algo = hash;

371 + else if (env) {

372 + int env_algo = hash_algo_by_name(env);

373 + if (env_algo == GIT_HASH_UNKNOWN)

374 + die(_("unknown hash algorithm '%s'"), env);

375 + repo_fmt->hash_algo = env_algo;

376 + }

377 }

378

379 int init_db(const char *git_dir, const char *real_git_dir,