Merge branch 'nd/worktree-move'

"git worktree" learned move and remove subcommands.

* nd/worktree-move:
  t2028: fix minor error and issues in newly-added "worktree move" tests
  worktree remove: allow it when $GIT_WORK_TREE is already gone
  worktree remove: new command
  worktree move: refuse to move worktrees with submodules
  worktree move: accept destination as directory
  worktree move: new command
  worktree.c: add update_worktree_location()
  worktree.c: add validate_worktree()

8 files changed, 452 insertions, 17 deletions

diff --git a/Documentation/git-worktree.txt b/Documentation/git-worktree.txt
index 5ac3f68ab5..e7eb24ab85 100644
--- a/Documentation/git-worktree.txt
+++ b/Documentation/git-worktree.txt
@@ -12,7 +12,9 @@ SYNOPSIS
 'git worktree add' [-f] [--detach] [--checkout] [--lock] [-b <new-branch>] <path> [<commit-ish>]
 'git worktree list' [--porcelain]
 'git worktree lock' [--reason <string>] <worktree>
+'git worktree move' <worktree> <new-path>
 'git worktree prune' [-n] [-v] [--expire <expire>]
+'git worktree remove' [--force] <worktree>
 'git worktree unlock' <worktree>
 
 DESCRIPTION
@@ -34,10 +36,6 @@ The working tree's administrative files in the repository (see
 `git worktree prune` in the main or any linked working tree to
 clean up any stale administrative files.
 
-If you move a linked working tree, you need to manually update the
-administrative files so that they do not get pruned automatically. See
-section "DETAILS" for more information.
-
 If a linked working tree is stored on a portable device or network share
 which is not always mounted, you can prevent its administrative files from
 being pruned by issuing the `git worktree lock` command, optionally
@@ -80,10 +78,22 @@ files from being pruned automatically. This also prevents it from
 being moved or deleted. Optionally, specify a reason for the lock
 with `--reason`.
 
+move::
+
+Move a working tree to a new location. Note that the main working tree
+or linked working trees containing submodules cannot be moved.
+
 prune::
 
 Prune working tree information in $GIT_DIR/worktrees.
 
+remove::
+
+Remove a working tree. Only clean working trees (no untracked files
+and no modification in tracked files) can be removed. Unclean working
+trees or ones with submodules can be removed with `--force`. The main
+working tree cannot be removed.
+
 unlock::
 
 Unlock a working tree, allowing it to be pruned, moved or deleted.
@@ -93,9 +103,10 @@ OPTIONS
 
 -f::
 --force::
-	By default, `add` refuses to create a new working tree when `<commit-ish>` is a branch name and
-	is already checked out by another working tree. This option overrides
-	that safeguard.
+	By default, `add` refuses to create a new working tree when
+	`<commit-ish>` is a branch name and is already checked out by
+	another working tree and `remove` refuses to remove an unclean
+	working tree. This option overrides that safeguard.
 
 -b <new-branch>::
 -B <new-branch>::
@@ -197,7 +208,7 @@ thumb is do not make any assumption about whether a path belongs to
 $GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
 inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
 
-If you move a linked working tree, you need to update the 'gitdir' file
+If you manually move a linked working tree, you need to update the 'gitdir' file
 in the entry's directory. For example, if a linked working tree is moved
 to `/newpath/test-next` and its `.git` file points to
 `/path/main/.git/worktrees/test-next`, then update
@@ -277,13 +288,6 @@ Multiple checkout in general is still experimental, and the support
 for submodules is incomplete. It is NOT recommended to make multiple
 checkouts of a superproject.
 
-git-worktree could provide more automation for tasks currently
-performed manually, such as:
-
-- `remove` to remove a linked working tree and its administrative files (and
-  warn if the working tree is dirty)
-- `mv` to move or rename a working tree and update its administrative files
-
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 4e7c98758f..1c1e576fdb 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -17,7 +17,9 @@ static const char * const worktree_usage[] = {
 	N_("git worktree add [<options>] <path> [<commit-ish>]"),
 	N_("git worktree list [<options>]"),
 	N_("git worktree lock [<options>] <path>"),
+	N_("git worktree move <worktree> <new-path>"),
 	N_("git worktree prune [<options>]"),
+	N_("git worktree remove [<options>] <worktree>"),
 	N_("git worktree unlock <path>"),
 	NULL
 };
@@ -619,6 +621,220 @@ static int unlock_worktree(int ac, const char **av, const char *prefix)
 	return ret;
 }
 
+static void validate_no_submodules(const struct worktree *wt)
+{
+	struct index_state istate = { NULL };
+	int i, found_submodules = 0;
+
+	if (read_index_from(&istate, worktree_git_path(wt, "index"),
+			    get_worktree_git_dir(wt)) > 0) {
+		for (i = 0; i < istate.cache_nr; i++) {
+			struct cache_entry *ce = istate.cache[i];
+
+			if (S_ISGITLINK(ce->ce_mode)) {
+				found_submodules = 1;
+				break;
+			}
+		}
+	}
+	discard_index(&istate);
+
+	if (found_submodules)
+		die(_("working trees containing submodules cannot be moved or removed"));
+}
+
+static int move_worktree(int ac, const char **av, const char *prefix)
+{
+	struct option options[] = {
+		OPT_END()
+	};
+	struct worktree **worktrees, *wt;
+	struct strbuf dst = STRBUF_INIT;
+	struct strbuf errmsg = STRBUF_INIT;
+	const char *reason;
+	char *path;
+
+	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
+	if (ac != 2)
+		usage_with_options(worktree_usage, options);
+
+	path = prefix_filename(prefix, av[1]);
+	strbuf_addstr(&dst, path);
+	free(path);
+
+	worktrees = get_worktrees(0);
+	wt = find_worktree(worktrees, prefix, av[0]);
+	if (!wt)
+		die(_("'%s' is not a working tree"), av[0]);
+	if (is_main_worktree(wt))
+		die(_("'%s' is a main working tree"), av[0]);
+	if (is_directory(dst.buf)) {
+		const char *sep = find_last_dir_sep(wt->path);
+
+		if (!sep)
+			die(_("could not figure out destination name from '%s'"),
+			    wt->path);
+		strbuf_trim_trailing_dir_sep(&dst);
+		strbuf_addstr(&dst, sep);
+	}
+	if (file_exists(dst.buf))
+		die(_("target '%s' already exists"), dst.buf);
+
+	validate_no_submodules(wt);
+
+	reason = is_worktree_locked(wt);
+	if (reason) {
+		if (*reason)
+			die(_("cannot move a locked working tree, lock reason: %s"),
+			    reason);
+		die(_("cannot move a locked working tree"));
+	}
+	if (validate_worktree(wt, &errmsg, 0))
+		die(_("validation failed, cannot move working tree: %s"),
+		    errmsg.buf);
+	strbuf_release(&errmsg);
+
+	if (rename(wt->path, dst.buf) == -1)
+		die_errno(_("failed to move '%s' to '%s'"), wt->path, dst.buf);
+
+	update_worktree_location(wt, dst.buf);
+
+	strbuf_release(&dst);
+	free_worktrees(worktrees);
+	return 0;
+}
+
+/*
+ * Note, "git status --porcelain" is used to determine if it's safe to
+ * delete a whole worktree. "git status" does not ignore user
+ * configuration, so if a normal "git status" shows "clean" for the
+ * user, then it's ok to remove it.
+ *
+ * This assumption may be a bad one. We may want to ignore
+ * (potentially bad) user settings and only delete a worktree when
+ * it's absolutely safe to do so from _our_ point of view because we
+ * know better.
+ */
+static void check_clean_worktree(struct worktree *wt,
+				 const char *original_path)
+{
+	struct argv_array child_env = ARGV_ARRAY_INIT;
+	struct child_process cp;
+	char buf[1];
+	int ret;
+
+	/*
+	 * Until we sort this out, all submodules are "dirty" and
+	 * will abort this function.
+	 */
+	validate_no_submodules(wt);
+
+	argv_array_pushf(&child_env, "%s=%s/.git",
+			 GIT_DIR_ENVIRONMENT, wt->path);
+	argv_array_pushf(&child_env, "%s=%s",
+			 GIT_WORK_TREE_ENVIRONMENT, wt->path);
+	memset(&cp, 0, sizeof(cp));
+	argv_array_pushl(&cp.args, "status",
+			 "--porcelain", "--ignore-submodules=none",
+			 NULL);
+	cp.env = child_env.argv;
+	cp.git_cmd = 1;
+	cp.dir = wt->path;
+	cp.out = -1;
+	ret = start_command(&cp);
+	if (ret)
+		die_errno(_("failed to run 'git status' on '%s'"),
+			  original_path);
+	ret = xread(cp.out, buf, sizeof(buf));
+	if (ret)
+		die(_("'%s' is dirty, use --force to delete it"),
+		    original_path);
+	close(cp.out);
+	ret = finish_command(&cp);
+	if (ret)
+		die_errno(_("failed to run 'git status' on '%s', code %d"),
+			  original_path, ret);
+}
+
+static int delete_git_work_tree(struct worktree *wt)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int ret = 0;
+
+	strbuf_addstr(&sb, wt->path);
+	if (remove_dir_recursively(&sb, 0)) {
+		error_errno(_("failed to delete '%s'"), sb.buf);
+		ret = -1;
+	}
+	strbuf_release(&sb);
+	return ret;
+}
+
+static int delete_git_dir(struct worktree *wt)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int ret = 0;
+
+	strbuf_addstr(&sb, git_common_path("worktrees/%s", wt->id));
+	if (remove_dir_recursively(&sb, 0)) {
+		error_errno(_("failed to delete '%s'"), sb.buf);
+		ret = -1;
+	}
+	strbuf_release(&sb);
+	return ret;
+}
+
+static int remove_worktree(int ac, const char **av, const char *prefix)
+{
+	int force = 0;
+	struct option options[] = {
+		OPT_BOOL(0, "force", &force,
+			 N_("force removing even if the worktree is dirty")),
+		OPT_END()
+	};
+	struct worktree **worktrees, *wt;
+	struct strbuf errmsg = STRBUF_INIT;
+	const char *reason;
+	int ret = 0;
+
+	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
+	if (ac != 1)
+		usage_with_options(worktree_usage, options);
+
+	worktrees = get_worktrees(0);
+	wt = find_worktree(worktrees, prefix, av[0]);
+	if (!wt)
+		die(_("'%s' is not a working tree"), av[0]);
+	if (is_main_worktree(wt))
+		die(_("'%s' is a main working tree"), av[0]);
+	reason = is_worktree_locked(wt);
+	if (reason) {
+		if (*reason)
+			die(_("cannot remove a locked working tree, lock reason: %s"),
+			    reason);
+		die(_("cannot remove a locked working tree"));
+	}
+	if (validate_worktree(wt, &errmsg, WT_VALIDATE_WORKTREE_MISSING_OK))
+		die(_("validation failed, cannot remove working tree: %s"),
+		    errmsg.buf);
+	strbuf_release(&errmsg);
+
+	if (file_exists(wt->path)) {
+		if (!force)
+			check_clean_worktree(wt, av[0]);
+
+		ret |= delete_git_work_tree(wt);
+	}
+	/*
+	 * continue on even if ret is non-zero, there's no going back
+	 * from here.
+	 */
+	ret |= delete_git_dir(wt);
+
+	free_worktrees(worktrees);
+	return ret;
+}
+
 int cmd_worktree(int ac, const char **av, const char *prefix)
 {
 	struct option options[] = {
@@ -641,5 +857,9 @@ int cmd_worktree(int ac, const char **av, const char *prefix)
 		return lock_worktree(ac - 1, av + 1, prefix);
 	if (!strcmp(av[1], "unlock"))
 		return unlock_worktree(ac - 1, av + 1, prefix);
+	if (!strcmp(av[1], "move"))
+		return move_worktree(ac - 1, av + 1, prefix);
+	if (!strcmp(av[1], "remove"))
+		return remove_worktree(ac - 1, av + 1, prefix);
 	usage_with_options(worktree_usage, options);
 }
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 91536d831c..66010707df 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -3087,7 +3087,7 @@ _git_whatchanged ()
 
 _git_worktree ()
 {
-	local subcommands="add list lock prune unlock"
+	local subcommands="add list lock move prune remove unlock"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
 		__gitcomp "$subcommands"
@@ -3105,6 +3105,9 @@ _git_worktree ()
 		prune,--*)
 			__gitcomp "--dry-run --expire --verbose"
 			;;
+		remove,--*)
+			__gitcomp "--force"
+			;;
 		*)
 			;;
 		esac
diff --git a/strbuf.c b/strbuf.c
index 5f138ed3c8..0759590b3e 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -95,6 +95,7 @@ void strbuf_trim(struct strbuf *sb)
 	strbuf_rtrim(sb);
 	strbuf_ltrim(sb);
 }
+
 void strbuf_rtrim(struct strbuf *sb)
 {
 	while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
@@ -102,6 +103,13 @@ void strbuf_rtrim(struct strbuf *sb)
 	sb->buf[sb->len] = '\0';
 }
 
+void strbuf_trim_trailing_dir_sep(struct strbuf *sb)
+{
+	while (sb->len > 0 && is_dir_sep((unsigned char)sb->buf[sb->len - 1]))
+		sb->len--;
+	sb->buf[sb->len] = '\0';
+}
+
 void strbuf_ltrim(struct strbuf *sb)
 {
 	char *b = sb->buf;
diff --git a/strbuf.h b/strbuf.h
index 14c8c10d66..e6cae5f439 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -179,6 +179,9 @@ extern void strbuf_trim(struct strbuf *);
 extern void strbuf_rtrim(struct strbuf *);
 extern void strbuf_ltrim(struct strbuf *);
 
+/* Strip trailing directory separators */
+extern void strbuf_trim_trailing_dir_sep(struct strbuf *);
+
 /**
  * Replace the contents of the strbuf with a reencoded form.  Returns -1
  * on error, 0 on success.
diff --git a/t/t2028-worktree-move.sh b/t/t2028-worktree-move.sh
index 8298aaf97f..5d5b3632ba 100755
--- a/t/t2028-worktree-move.sh
+++ b/t/t2028-worktree-move.sh
@@ -7,7 +7,8 @@ test_description='test git worktree move, remove, lock and unlock'
 test_expect_success 'setup' '
 	test_commit init &&
 	git worktree add source &&
-	git worktree list --porcelain | grep "^worktree" >actual &&
+	git worktree list --porcelain >out &&
+	grep "^worktree" out >actual &&
 	cat <<-EOF >expected &&
 	worktree $(pwd)
 	worktree $(pwd)/source
@@ -59,4 +60,86 @@ test_expect_success 'unlock worktree twice' '
 	test_path_is_missing .git/worktrees/source/locked
 '
 
+test_expect_success 'move non-worktree' '
+	mkdir abc &&
+	test_must_fail git worktree move abc def
+'
+
+test_expect_success 'move locked worktree' '
+	git worktree lock source &&
+	test_when_finished "git worktree unlock source" &&
+	test_must_fail git worktree move source destination
+'
+
+test_expect_success 'move worktree' '
+	toplevel="$(pwd)" &&
+	git worktree move source destination &&
+	test_path_is_missing source &&
+	git worktree list --porcelain >out &&
+	grep "^worktree.*/destination" out &&
+	! grep "^worktree.*/source" out &&
+	git -C destination log --format=%s >actual2 &&
+	echo init >expected2 &&
+	test_cmp expected2 actual2
+'
+
+test_expect_success 'move main worktree' '
+	test_must_fail git worktree move . def
+'
+
+test_expect_success 'move worktree to another dir' '
+	mkdir some-dir &&
+	git worktree move destination some-dir &&
+	test_when_finished "git worktree move some-dir/destination destination" &&
+	test_path_is_missing destination &&
+	git worktree list --porcelain >out &&
+	grep "^worktree.*/some-dir/destination" out &&
+	git -C some-dir/destination log --format=%s >actual2 &&
+	echo init >expected2 &&
+	test_cmp expected2 actual2
+'
+
+test_expect_success 'remove main worktree' '
+	test_must_fail git worktree remove .
+'
+
+test_expect_success 'remove locked worktree' '
+	git worktree lock destination &&
+	test_when_finished "git worktree unlock destination" &&
+	test_must_fail git worktree remove destination
+'
+
+test_expect_success 'remove worktree with dirty tracked file' '
+	echo dirty >>destination/init.t &&
+	test_when_finished "git -C destination checkout init.t" &&
+	test_must_fail git worktree remove destination
+'
+
+test_expect_success 'remove worktree with untracked file' '
+	: >destination/untracked &&
+	test_must_fail git worktree remove destination
+'
+
+test_expect_success 'force remove worktree with untracked file' '
+	git worktree remove --force destination &&
+	test_path_is_missing destination
+'
+
+test_expect_success 'remove missing worktree' '
+	git worktree add to-be-gone &&
+	test -d .git/worktrees/to-be-gone &&
+	mv to-be-gone gone &&
+	git worktree remove to-be-gone &&
+	test_path_is_missing .git/worktrees/to-be-gone
+'
+
+test_expect_success 'NOT remove missing-but-locked worktree' '
+	git worktree add gone-but-locked &&
+	git worktree lock gone-but-locked &&
+	test -d .git/worktrees/gone-but-locked &&
+	mv gone-but-locked really-gone-now &&
+	test_must_fail git worktree remove gone-but-locked &&
+	test_path_is_dir .git/worktrees/gone-but-locked
+'
+
 test_done
diff --git a/worktree.c b/worktree.c
index f5da7d286d..28989cf06e 100644
--- a/worktree.c
+++ b/worktree.c
@@ -254,6 +254,102 @@ const char *is_worktree_locked(struct worktree *wt)
 	return wt->lock_reason;
 }
 
+/* convenient wrapper to deal with NULL strbuf */
+static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
+{
+	va_list params;
+
+	if (!buf)
+		return;
+
+	va_start(params, fmt);
+	strbuf_vaddf(buf, fmt, params);
+	va_end(params);
+}
+
+int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
+		      unsigned flags)
+{
+	struct strbuf wt_path = STRBUF_INIT;
+	char *path = NULL;
+	int err, ret = -1;
+
+	strbuf_addf(&wt_path, "%s/.git", wt->path);
+
+	if (is_main_worktree(wt)) {
+		if (is_directory(wt_path.buf)) {
+			ret = 0;
+			goto done;
+		}
+		/*
+		 * Main worktree using .git file to point to the
+		 * repository would make it impossible to know where
+		 * the actual worktree is if this function is executed
+		 * from another worktree. No .git file support for now.
+		 */
+		strbuf_addf_gently(errmsg,
+				   _("'%s' at main working tree is not the repository directory"),
+				   wt_path.buf);
+		goto done;
+	}
+
+	/*
+	 * Make sure "gitdir" file points to a real .git file and that
+	 * file points back here.
+	 */
+	if (!is_absolute_path(wt->path)) {
+		strbuf_addf_gently(errmsg,
+				   _("'%s' file does not contain absolute path to the working tree location"),
+				   git_common_path("worktrees/%s/gitdir", wt->id));
+		goto done;
+	}
+
+	if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
+	    !file_exists(wt->path)) {
+		ret = 0;
+		goto done;
+	}
+
+	if (!file_exists(wt_path.buf)) {
+		strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
+		goto done;
+	}
+
+	path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
+	if (!path) {
+		strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
+				   wt_path.buf, err);
+		goto done;
+	}
+
+	ret = fspathcmp(path, real_path(git_common_path("worktrees/%s", wt->id)));
+
+	if (ret)
+		strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
+				   wt->path, git_common_path("worktrees/%s", wt->id));
+done:
+	free(path);
+	strbuf_release(&wt_path);
+	return ret;
+}
+
+void update_worktree_location(struct worktree *wt, const char *path_)
+{
+	struct strbuf path = STRBUF_INIT;
+
+	if (is_main_worktree(wt))
+		die("BUG: can't relocate main worktree");
+
+	strbuf_realpath(&path, path_, 1);
+	if (fspathcmp(wt->path, path.buf)) {
+		write_file(git_common_path("worktrees/%s/gitdir", wt->id),
+			   "%s/.git", path.buf);
+		free(wt->path);
+		wt->path = strbuf_detach(&path, NULL);
+	}
+	strbuf_release(&path);
+}
+
 int is_worktree_being_rebased(const struct worktree *wt,
 			      const char *target)
 {
diff --git a/worktree.h b/worktree.h
index c28a880e18..fe38ce10c3 100644
--- a/worktree.h
+++ b/worktree.h
@@ -3,6 +3,8 @@
 
 #include "refs.h"
 
+struct strbuf;
+
 struct worktree {
 	char *path;
 	char *id;
@@ -59,6 +61,22 @@ extern int is_main_worktree(const struct worktree *wt);
  */
 extern const char *is_worktree_locked(struct worktree *wt);
 
+#define WT_VALIDATE_WORKTREE_MISSING_OK (1 << 0)
+
+/*
+ * Return zero if the worktree is in good condition. Error message is
+ * returned if "errmsg" is not NULL.
+ */
+extern int validate_worktree(const struct worktree *wt,
+			     struct strbuf *errmsg,
+			     unsigned flags);
+
+/*
+ * Update worktrees/xxx/gitdir with the new path.
+ */
+extern void update_worktree_location(struct worktree *wt,
+				     const char *path_);
+
 /*
  * Free up the memory for worktree(s)
  */