worktree add: add --orphan flag

Add support for creating an orphan branch when adding a new worktree.
The functionality of this flag is equivalent to git switch's --orphan
option.

Current Behavior:
% git -C foo.git --no-pager branch -l
+ main
% git -C foo.git worktree add main/
Preparing worktree (new branch 'main')
HEAD is now at 6c93a75 a commit
%

% git init bar.git
Initialized empty Git repository in /path/to/bar.git/
% git -C bar.git --no-pager branch -l

% git -C bar.git worktree add main/
Preparing worktree (new branch 'main')
fatal: not a valid object name: 'HEAD'
%

New Behavior:

% git -C foo.git --no-pager branch -l
+ main
% git -C foo.git worktree add main/
Preparing worktree (new branch 'main')
HEAD is now at 6c93a75 a commit
%

% git init --bare bar.git
Initialized empty Git repository in /path/to/bar.git/
% git -C bar.git --no-pager branch -l

% git -C bar.git worktree add main/
Preparing worktree (new branch 'main')
fatal: invalid reference: HEAD
% git -C bar.git worktree add --orphan -b main/
Preparing worktree (new branch 'main')
% git -C bar.git worktree add --orphan -b newbranch worktreedir/
Preparing worktree (new branch 'newbranch')
%

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jacob Abel <jacobabel@nullpo.dev>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-worktree.txt b/Documentation/git-worktree.txt
index b9c12779f1af1c9d215e399aba8392dd8ccd9cde..485d865eb2fffb3133c0b0db11b9809ffe31840a 100644 (file)
--- a/Documentation/git-worktree.txt
+++ b/Documentation/git-worktree.txt
@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git worktree add' [-f] [--detach] [--checkout] [--lock [--reason <string>]]
-                  [(-b | -B) <new-branch>] <path> [<commit-ish>]
+                  [--orphan] [(-b | -B) <new-branch>] <path> [<commit-ish>]
 'git worktree list' [-v | --porcelain [-z]]
 'git worktree lock' [--reason <string>] <worktree>
 'git worktree move' <worktree> <new-path>
@@ -222,6 +222,10 @@ This can also be set up as the default behaviour by using the
        With `prune`, do not remove anything; just report what it would
        remove.
 
+--orphan::
+       With `add`, make the new worktree and index empty, associating
+       the worktree with a new orphan/unborn branch named `<new-branch>`.
+
 --porcelain::
        With `list`, output in an easy-to-parse format for scripts.
        This format will remain stable across Git versions and regardless of user

diff --git a/builtin/worktree.c b/builtin/worktree.c
index d1b4b53f2c36b28b1b2a8db539b80f9914b9e965..48de7fc3b023c69e5635d90b1e428b79e6dd7af1 100644 (file)
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -22,7 +22,8 @@
 
 #define BUILTIN_WORKTREE_ADD_USAGE \
        N_("git worktree add [-f] [--detach] [--checkout] [--lock [--reason <string>]]\n" \
-          "                 [(-b | -B) <new-branch>] <path> [<commit-ish>]")
+          "                 [--orphan] [(-b | -B) <new-branch>] <path> [<commit-ish>]")
+
 #define BUILTIN_WORKTREE_LIST_USAGE \
        N_("git worktree list [-v | --porcelain [-z]]")
 #define BUILTIN_WORKTREE_LOCK_USAGE \
@@ -95,6 +96,7 @@ struct add_opts {
        int detach;
        int quiet;
        int checkout;
+       int orphan;
        const char *keep_locked;
 };
 
@@ -368,6 +370,22 @@ static int checkout_worktree(const struct add_opts *opts,
        return run_command(&cp);
 }
 
+static int make_worktree_orphan(const char * ref, const struct add_opts *opts,
+                               struct strvec *child_env)
+{
+       struct strbuf symref = STRBUF_INIT;
+       struct child_process cp = CHILD_PROCESS_INIT;
+
+       validate_new_branchname(ref, &symref, 0);
+       strvec_pushl(&cp.args, "symbolic-ref", "HEAD", symref.buf, NULL);
+       if (opts->quiet)
+               strvec_push(&cp.args, "--quiet");
+       strvec_pushv(&cp.env, child_env->v);
+       strbuf_release(&symref);
+       cp.git_cmd = 1;
+       return run_command(&cp);
+}
+
 static int add_worktree(const char *path, const char *refname,
                        const struct add_opts *opts)
 {
@@ -397,7 +415,7 @@ static int add_worktree(const char *path, const char *refname,
                        die_if_checked_out(symref.buf, 0);
        }
        commit = lookup_commit_reference_by_name(refname);
-       if (!commit)
+       if (!commit && !opts->orphan)
                die(_("invalid reference: %s"), refname);
 
        name = worktree_basename(path, &len);
@@ -486,10 +504,10 @@ static int add_worktree(const char *path, const char *refname,
        strvec_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path);
        cp.git_cmd = 1;
 
-       if (!is_branch)
+       if (!is_branch && commit) {
                strvec_pushl(&cp.args, "update-ref", "HEAD",
                             oid_to_hex(&commit->object.oid), NULL);
-       else {
+       } else {
                strvec_pushl(&cp.args, "symbolic-ref", "HEAD",
                             symref.buf, NULL);
                if (opts->quiet)
@@ -501,6 +519,10 @@ static int add_worktree(const char *path, const char *refname,
        if (ret)
                goto done;
 
+       if (opts->orphan &&
+           (ret = make_worktree_orphan(refname, opts, &child_env)))
+               goto done;
+
        if (opts->checkout &&
            (ret = checkout_worktree(opts, &child_env)))
                goto done;
@@ -520,7 +542,7 @@ done:
         * Hook failure does not warrant worktree deletion, so run hook after
         * is_junk is cleared, but do return appropriate code when hook fails.
         */
-       if (!ret && opts->checkout) {
+       if (!ret && opts->checkout && !opts->orphan) {
                struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 
                strvec_pushl(&opt.env, "GIT_DIR", "GIT_WORK_TREE", NULL);
@@ -568,7 +590,7 @@ static void print_preparing_worktree_line(int detach,
                else {
                        struct commit *commit = lookup_commit_reference_by_name(branch);
                        if (!commit)
-                               die(_("invalid reference: %s"), branch);
+                               BUG(_("unreachable: invalid reference: %s"), branch);
                        fprintf_ln(stderr, _("Preparing worktree (detached HEAD %s)"),
                                  repo_find_unique_abbrev(the_repository, &commit->object.oid, DEFAULT_ABBREV));
                }
@@ -620,6 +642,7 @@ static int add(int ac, const char **av, const char *prefix)
                           N_("create a new branch")),
                OPT_STRING('B', NULL, &new_branch_force, N_("branch"),
                           N_("create or reset a branch")),
+               OPT_BOOL(0, "orphan", &opts.orphan, N_("create unborn/orphaned branch")),
                OPT_BOOL('d', "detach", &opts.detach, N_("detach HEAD at named commit")),
                OPT_BOOL(0, "checkout", &opts.checkout, N_("populate the new working tree")),
                OPT_BOOL(0, "lock", &keep_locked, N_("keep the new working tree locked")),
@@ -640,6 +663,17 @@ static int add(int ac, const char **av, const char *prefix)
        ac = parse_options(ac, av, prefix, options, git_worktree_add_usage, 0);
        if (!!opts.detach + !!new_branch + !!new_branch_force > 1)
                die(_("options '%s', '%s', and '%s' cannot be used together"), "-b", "-B", "--detach");
+       if (opts.detach && opts.orphan)
+               die(_("options '%s', and '%s' cannot be used together"),
+                   "--orphan", "--detach");
+       if (opts.orphan && opt_track)
+               die(_("'%s' and '%s' cannot be used together"), "--orphan", "--track");
+       if (opts.orphan && !opts.checkout)
+               die(_("'%s' and '%s' cannot be used together"), "--orphan",
+                   "--no-checkout");
+       if (opts.orphan && ac == 2)
+               die(_("'%s' and '%s' cannot be used together"), "--orphan",
+                   _("<commit-ish>"));
        if (lock_reason && !keep_locked)
                die(_("the option '%s' requires '%s'"), "--reason", "--lock");
        if (lock_reason)
@@ -668,13 +702,17 @@ static int add(int ac, const char **av, const char *prefix)
                strbuf_release(&symref);
        }
 
-       if (ac < 2 && !new_branch && !opts.detach) {
+       if (opts.orphan && !new_branch) {
+               int n;
+               const char *s = worktree_basename(path, &n);
+               new_branch = xstrndup(s, n);
+       } else if (new_branch || opts.detach || opts.orphan) {
+               // No-op
+       } else if (ac < 2) {
                const char *s = dwim_branch(path, &new_branch);
                if (s)
                        branch = s;
-       }
-
-       if (ac == 2 && !new_branch && !opts.detach) {
+       } else if (ac == 2) {
                struct object_id oid;
                struct commit *commit;
                const char *remote;
@@ -688,10 +726,17 @@ static int add(int ac, const char **av, const char *prefix)
                        }
                }
        }
+
+       if (!opts.orphan && !lookup_commit_reference_by_name(branch)) {
+               die(_("invalid reference: %s"), branch);
+       }
+
        if (!opts.quiet)
                print_preparing_worktree_line(opts.detach, branch, new_branch, !!new_branch_force);
 
-       if (new_branch) {
+       if (opts.orphan) {
+               branch = new_branch;
+       } else if (new_branch) {
                struct child_process cp = CHILD_PROCESS_INIT;
                cp.git_cmd = 1;
                strvec_push(&cp.args, "branch");

diff --git a/t/t2400-worktree-add.sh b/t/t2400-worktree-add.sh
index 841f15f59eb2692ce0e93d673573b26c5be66e2f..fba90582b67d526144d2d2edea27ff99026612ca 100755 (executable)
--- a/t/t2400-worktree-add.sh
+++ b/t/t2400-worktree-add.sh
@@ -312,6 +312,10 @@ test_wt_add_excl () {
 test_wt_add_excl -b poodle -B poodle bamboo main
 test_wt_add_excl -b poodle --detach bamboo main
 test_wt_add_excl -B poodle --detach bamboo main
+test_wt_add_excl --orphan --detach bamboo
+test_wt_add_excl --orphan --no-checkout bamboo
+test_wt_add_excl --orphan bamboo main
+test_wt_add_excl --orphan -b bamboo wtdir/ main
 
 test_expect_success '"add -B" fails if the branch is checked out' '
        git rev-parse newmain >before &&
@@ -341,6 +345,62 @@ test_expect_success 'add --quiet -b' '
        test_must_be_empty actual
 '
 
+test_expect_success '"add --orphan"' '
+       test_when_finished "git worktree remove -f -f orphandir" &&
+       git worktree add --orphan -b neworphan orphandir &&
+       echo refs/heads/neworphan >expected &&
+       git -C orphandir symbolic-ref HEAD >actual &&
+       test_cmp expected actual
+'
+
+test_expect_success '"add --orphan (no -b)"' '
+       test_when_finished "git worktree remove -f -f neworphan" &&
+       git worktree add --orphan neworphan &&
+       echo refs/heads/neworphan >expected &&
+       git -C neworphan symbolic-ref HEAD >actual &&
+       test_cmp expected actual
+'
+
+test_expect_success '"add --orphan --quiet"' '
+       test_when_finished "git worktree remove -f -f orphandir" &&
+       git worktree add --quiet --orphan -b neworphan orphandir 2>log.actual &&
+       test_must_be_empty log.actual &&
+       echo refs/heads/neworphan >expected &&
+       git -C orphandir symbolic-ref HEAD >actual &&
+       test_cmp expected actual
+'
+
+test_expect_success '"add --orphan" fails if the branch already exists' '
+       test_when_finished "git branch -D existingbranch" &&
+       git worktree add -b existingbranch orphandir main &&
+       git worktree remove orphandir &&
+       test_must_fail git worktree add --orphan -b existingbranch orphandir
+'
+
+test_expect_success '"add --orphan" with empty repository' '
+       test_when_finished "rm -rf empty_repo" &&
+       echo refs/heads/newbranch >expected &&
+       GIT_DIR="empty_repo" git init --bare &&
+       git -C empty_repo worktree add --orphan -b newbranch worktreedir &&
+       git -C empty_repo/worktreedir symbolic-ref HEAD >actual &&
+       test_cmp expected actual
+'
+
+test_expect_success '"add" worktree with orphan branch and lock' '
+       git worktree add --lock --orphan -b orphanbr orphan-with-lock &&
+       test_when_finished "git worktree unlock orphan-with-lock || :" &&
+       test -f .git/worktrees/orphan-with-lock/locked
+'
+
+test_expect_success '"add" worktree with orphan branch, lock, and reason' '
+       lock_reason="why not" &&
+       git worktree add --detach --lock --reason "$lock_reason" orphan-with-lock-reason main &&
+       test_when_finished "git worktree unlock orphan-with-lock-reason || :" &&
+       test -f .git/worktrees/orphan-with-lock-reason/locked &&
+       echo "$lock_reason" >expect &&
+       test_cmp expect .git/worktrees/orphan-with-lock-reason/locked
+'
+
 test_expect_success 'local clone from linked checkout' '
        git clone --local here here-clone &&
        ( cd here-clone && git fsck )
@@ -457,6 +517,14 @@ setup_remote_repo () {
        )
 }
 
+test_expect_success '"add" <path> <remote/branch> w/ no HEAD' '
+       test_when_finished rm -rf repo_upstream repo_local foo &&
+       setup_remote_repo repo_upstream repo_local &&
+       git -C repo_local config --bool core.bare true &&
+       git -C repo_local branch -D main &&
+       git -C repo_local worktree add ./foo repo_upstream/foo
+'
+
 test_expect_success '--no-track avoids setting up tracking' '
        test_when_finished rm -rf repo_upstream repo_local foo &&
        setup_remote_repo repo_upstream repo_local &&