worktree: add "unlock" command

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-worktree.txt

diff --git a/Documentation/git-worktree.txt b/Documentation/git-worktree.txt
index b49b25b..27330c5 100644
--- a/Documentation/git-worktree.txt
+++ b/Documentation/git-worktree.txt
@@ -13,6 +13,7 @@
 'git worktree list' [--porcelain]
 'git worktree lock' [--reason <string>] <worktree>
 'git worktree prune' [-n] [-v] [--expire <expire>]
+'git worktree unlock' <worktree>
 
 DESCRIPTION
 -----------
@@ -73,6 +74,10 @@
 
 Prune working tree information in $GIT_DIR/worktrees.
 
+unlock::
+
+Unlock a working tree, allowing it to be pruned, moved or deleted.
+
 OPTIONS
 -------
 

builtin/worktree.c

diff --git a/builtin/worktree.c b/builtin/worktree.c
index 3b9220f..4877421 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -16,6 +16,7 @@
 	N_("git worktree list [<options>]"),
 	N_("git worktree lock [<options>] <path>"),
 	N_("git worktree prune [<options>]"),
+	N_("git worktree unlock <path>"),
 	NULL
 };
 
@@ -495,6 +496,31 @@
 	return 0;
 }
 
+static int unlock_worktree(int ac, const char **av, const char *prefix)
+{
+	struct option options[] = {
+		OPT_END()
+	};
+	struct worktree **worktrees, *wt;
+	int ret;
+
+	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
+	if (ac != 1)
+		usage_with_options(worktree_usage, options);
+
+	worktrees = get_worktrees();
+	wt = find_worktree(worktrees, prefix, av[0]);
+	if (!wt)
+		die(_("'%s' is not a working tree"), av[0]);
+	if (is_main_worktree(wt))
+		die(_("The main working tree cannot be locked or unlocked"));
+	if (!is_worktree_locked(wt))
+		die(_("'%s' is not locked"), av[0]);
+	ret = unlink_or_warn(git_common_path("worktrees/%s/locked", wt->id));
+	free_worktrees(worktrees);
+	return ret;
+}
+
 int cmd_worktree(int ac, const char **av, const char *prefix)
 {
 	struct option options[] = {
@@ -513,5 +539,7 @@
 		return list(ac - 1, av + 1, prefix);
 	if (!strcmp(av[1], "lock"))
 		return lock_worktree(ac - 1, av + 1, prefix);
+	if (!strcmp(av[1], "unlock"))
+		return unlock_worktree(ac - 1, av + 1, prefix);
 	usage_with_options(worktree_usage, options);
 }

contrib/completion/git-completion.bash

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index f88727d..0e3841d 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -2597,7 +2597,7 @@
 
 _git_worktree ()
 {
-	local subcommands="add list lock prune"
+	local subcommands="add list lock prune unlock"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
 		__gitcomp "$subcommands"

t/t2028-worktree-move.sh

diff --git a/t/t2028-worktree-move.sh b/t/t2028-worktree-move.sh
index 3a8512c..8298aaf 100755
--- a/t/t2028-worktree-move.sh
+++ b/t/t2028-worktree-move.sh
@@ -45,4 +45,18 @@
 	test_cmp expected .git/worktrees/source/locked
 '
 
+test_expect_success 'unlock main worktree' '
+	test_must_fail git worktree unlock .
+'
+
+test_expect_success 'unlock linked worktree' '
+	git worktree unlock source &&
+	test_path_is_missing .git/worktrees/source/locked
+'
+
+test_expect_success 'unlock worktree twice' '
+	test_must_fail git worktree unlock source &&
+	test_path_is_missing .git/worktrees/source/locked
+'
+
 test_done