init: disallow --separate-git-dir with bare repository

The purpose of "git init --separate-git-dir" is to separate the repository from the worktree. This is true even when --separate-git-dir is used on an existing worktree, in which case, it moves the .git/ subdirectory to a new location outside the worktree. However, an outright bare repository (such as one created by "git init --bare"), has no worktree, so using --separate-git-dir to separate it from its non-existent worktree is nonsensical. Therefore, make it an error to use --separate-git-dir on a bare repository. Implementation note: "git init" considers a repository bare if told so explicitly via --bare or if it guesses it to be so based upon heuristics. In the explicit --bare case, a conflict with --separate-git-dir is easy to detect early. In the guessed case, however, the conflict can only be detected once "bareness" is guessed, which happens after "git init" has begun creating the repository. Technically, we can get by with a single late check which would cover both cases, however, erroring out early, when possible, without leaving detritus provides a better user experience. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Eric Sunshine committed Aug 9, 2020 at 18:53 UTC ccf236a23adb5cfb4e5285daad083149458d7828

2 files changed +18

builtin/init-db.c

@@ -568,6 +568,9 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)

568

569 argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);

570

571 + if (real_git_dir && is_bare_repository_cfg == 1)

572 + die(_("--separate-git-dir and --bare are mutually exclusive"));

573 +

574 if (real_git_dir && !is_absolute_path(real_git_dir))

575 real_git_dir = real_pathdup(real_git_dir, 1);

576

@@ -663,6 +666,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)

666 get_git_work_tree());

667 }

668 else {

669 + if (real_git_dir)

670 + die(_("--separate-git-dir incompatible with bare repository"));

671 if (work_tree)

672 set_git_work_tree(work_tree);

673 }

t/t0001-init.sh

+13

@@ -316,6 +316,19 @@ test_expect_success 'init with separate gitdir' '

316 test_path_is_dir realgitdir/refs

317 '

318

319 +test_expect_success 'explicit bare & --separate-git-dir incompatible' '

320 + test_must_fail git init --bare --separate-git-dir goop.git bare.git 2>err &&

321 + test_i18ngrep "mutually exclusive" err

322 +'

323 +

324 +test_expect_success 'implicit bare & --separate-git-dir incompatible' '

325 + test_when_finished "rm -rf bare.git" &&

326 + mkdir -p bare.git &&

327 + test_must_fail env GIT_DIR=. \

328 + git -C bare.git init --separate-git-dir goop.git 2>err &&

329 + test_i18ngrep "incompatible" err

330 +'

331 +

332 test_lazy_prereq GETCWD_IGNORES_PERMS '

333 base=GETCWD_TEST_BASE_DIR &&

334 mkdir -p $base/dir &&