Merge branch 'es/worktree-forced-ops-fix'

Fix a bug in which the same path could be registered under multiple
worktree entries if the path was missing (for instance, was removed
manually).  Also, as a convenience, expand the number of cases in
which --force is applicable.

* es/worktree-forced-ops-fix:
  doc-diff: force worktree add
  worktree: delete .git/worktrees if empty after 'remove'
  worktree: teach 'remove' to override lock when --force given twice
  worktree: teach 'move' to override lock when --force given twice
  worktree: teach 'add' to respect --force for registered but missing path
  worktree: disallow adding same path multiple times
  worktree: prepare for more checks of whether path can become worktree
  worktree: generalize delete_git_dir() to reduce code duplication
  worktree: move delete_git_dir() earlier in file for upcoming new callers
  worktree: don't die() in library function find_worktree()

Documentation/doc-diff

@@ -75,7 +75,7 @@ fi
 # results that don't differ between the two trees.
 if ! test -d "$tmp/worktree"
 then
-	git worktree add --detach "$tmp/worktree" "$from" &&
+	git worktree add -f --detach "$tmp/worktree" "$from" &&
 	dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
 	ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
 fi

Documentation/git-worktree.txt

@@ -120,8 +120,16 @@ OPTIONS
 --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 and `remove` refuses to remove an unclean
-	working tree. This option overrides these safeguards.
+	another working tree, or if `<path>` is already assigned to some
+	working tree but is missing (for instance, if `<path>` was deleted
+	manually). This option overrides these safeguards. To add a missing but
+	locked working tree path, specify `--force` twice.
++
+`move` refuses to move a locked working tree unless `--force` is specified
+twice.
++
+`remove` refuses to remove an unclean working tree unless `--force` is used.
+To remove a locked working tree, specify `--force` twice.
 
 -b <new-branch>::
 -B <new-branch>::

builtin/worktree.c

@@ -47,6 +47,26 @@ static int git_worktree_config(const char *var, const char *value, void *cb)
 	return git_default_config(var, value, cb);
 }
 
+static int delete_git_dir(const char *id)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int ret;
+
+	strbuf_addstr(&sb, git_common_path("worktrees/%s", id));
+	ret = remove_dir_recursively(&sb, 0);
+	if (ret < 0 && errno == ENOTDIR)
+		ret = unlink(sb.buf);
+	if (ret)
+		error_errno(_("failed to delete '%s'"), sb.buf);
+	strbuf_release(&sb);
+	return ret;
+}
+
+static void delete_worktrees_dir_if_empty(void)
+{
+	rmdir(git_path("worktrees")); /* ignore failed removal */
+}
+
 static int prune_worktree(const char *id, struct strbuf *reason)
 {
 	struct stat st;
@@ -116,10 +136,8 @@ static int prune_worktree(const char *id, struct strbuf *reason)
 static void prune_worktrees(void)
 {
 	struct strbuf reason = STRBUF_INIT;
-	struct strbuf path = STRBUF_INIT;
 	DIR *dir = opendir(git_path("worktrees"));
 	struct dirent *d;
-	int ret;
 	if (!dir)
 		return;
 	while ((d = readdir(dir)) != NULL) {
@@ -132,18 +150,12 @@ static void prune_worktrees(void)
 			printf("%s\n", reason.buf);
 		if (show_only)
 			continue;
-		git_path_buf(&path, "worktrees/%s", d->d_name);
-		ret = remove_dir_recursively(&path, 0);
-		if (ret < 0 && errno == ENOTDIR)
-			ret = unlink(path.buf);
-		if (ret)
-			error_errno(_("failed to remove '%s'"), path.buf);
+		delete_git_dir(d->d_name);
 	}
 	closedir(dir);
 	if (!show_only)
-		rmdir(git_path("worktrees"));
+		delete_worktrees_dir_if_empty();
 	strbuf_release(&reason);
-	strbuf_release(&path);
 }
 
 static int prune(int ac, const char **av, const char *prefix)
@@ -212,6 +224,43 @@ static const char *worktree_basename(const char *path, int *olen)
 	return name;
 }
 
+static void validate_worktree_add(const char *path, const struct add_opts *opts)
+{
+	struct worktree **worktrees;
+	struct worktree *wt;
+	int locked;
+
+	if (file_exists(path) && !is_empty_dir(path))
+		die(_("'%s' already exists"), path);
+
+	worktrees = get_worktrees(0);
+	/*
+	 * find_worktree()'s suffix matching may undesirably find the main
+	 * rather than a linked worktree (for instance, when the basenames
+	 * of the main worktree and the one being created are the same).
+	 * We're only interested in linked worktrees, so skip the main
+	 * worktree with +1.
+	 */
+	wt = find_worktree(worktrees + 1, NULL, path);
+	if (!wt)
+		goto done;
+
+	locked = !!is_worktree_locked(wt);
+	if ((!locked && opts->force) || (locked && opts->force > 1)) {
+		if (delete_git_dir(wt->id))
+		    die(_("unable to re-add worktree '%s'"), path);
+		goto done;
+	}
+
+	if (locked)
+		die(_("'%s' is a missing but locked worktree;\nuse 'add -f -f' to override, or 'unlock' and 'prune' or 'remove' to clear"), path);
+	else
+		die(_("'%s' is a missing but already registered worktree;\nuse 'add -f' to override, or 'prune' or 'remove' to clear"), path);
+
+done:
+	free_worktrees(worktrees);
+}
+
 static int add_worktree(const char *path, const char *refname,
 			const struct add_opts *opts)
 {
@@ -226,8 +275,7 @@ static int add_worktree(const char *path, const char *refname,
 	struct commit *commit = NULL;
 	int is_branch = 0;
 
-	if (file_exists(path) && !is_empty_dir(path))
-		die(_("'%s' already exists"), path);
+	validate_worktree_add(path, opts);
 
 	/* is 'refname' a branch or commit? */
 	if (!opts->detach && !strbuf_check_branch_ref(&symref, refname) &&
@@ -697,13 +745,17 @@ static void validate_no_submodules(const struct worktree *wt)
 
 static int move_worktree(int ac, const char **av, const char *prefix)
 {
+	int force = 0;
 	struct option options[] = {
+		OPT__FORCE(&force,
+			 N_("force move even if worktree is dirty or locked"),
+			 PARSE_OPT_NOCOMPLETE),
 		OPT_END()
 	};
 	struct worktree **worktrees, *wt;
 	struct strbuf dst = STRBUF_INIT;
 	struct strbuf errmsg = STRBUF_INIT;
-	const char *reason;
+	const char *reason = NULL;
 	char *path;
 
 	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
@@ -734,12 +786,13 @@ static int move_worktree(int ac, const char **av, const char *prefix)
 
 	validate_no_submodules(wt);
 
+	if (force < 2)
 		reason = is_worktree_locked(wt);
 	if (reason) {
 		if (*reason)
-			die(_("cannot move a locked working tree, lock reason: %s"),
+			die(_("cannot move a locked working tree, lock reason: %s\nuse 'move -f -f' to override or unlock first"),
 			    reason);
-		die(_("cannot move a locked working tree"));
+		die(_("cannot move a locked working tree;\nuse 'move -f -f' to override or unlock first"));
 	}
 	if (validate_worktree(wt, &errmsg, 0))
 		die(_("validation failed, cannot move working tree: %s"),
@@ -822,32 +875,18 @@ static int delete_git_work_tree(struct worktree *wt)
 	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__FORCE(&force,
-			 N_("force removing even if the worktree is dirty"),
+			 N_("force removal even if worktree is dirty or locked"),
 			 PARSE_OPT_NOCOMPLETE),
 		OPT_END()
 	};
 	struct worktree **worktrees, *wt;
 	struct strbuf errmsg = STRBUF_INIT;
-	const char *reason;
+	const char *reason = NULL;
 	int ret = 0;
 
 	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
@@ -860,12 +899,13 @@ static int remove_worktree(int ac, const char **av, const char *prefix)
 		die(_("'%s' is not a working tree"), av[0]);
 	if (is_main_worktree(wt))
 		die(_("'%s' is a main working tree"), av[0]);
+	if (force < 2)
 		reason = is_worktree_locked(wt);
 	if (reason) {
 		if (*reason)
-			die(_("cannot remove a locked working tree, lock reason: %s"),
+			die(_("cannot remove a locked working tree, lock reason: %s\nuse 'remove -f -f' to override or unlock first"),
 			    reason);
-		die(_("cannot remove a locked working tree"));
+		die(_("cannot remove a locked working tree;\nuse 'remove -f -f' to override or unlock first"));
 	}
 	if (validate_worktree(wt, &errmsg, WT_VALIDATE_WORKTREE_MISSING_OK))
 		die(_("validation failed, cannot remove working tree: %s"),
@@ -882,7 +922,8 @@ static int remove_worktree(int ac, const char **av, const char *prefix)
 	 * continue on even if ret is non-zero, there's no going back
 	 * from here.
 	 */
-	ret |= delete_git_dir(wt);
+	ret |= delete_git_dir(wt->id);
+	delete_worktrees_dir_if_empty();
 
 	free_worktrees(worktrees);
 	return ret;

t/t2025-worktree-add.sh

@@ -552,4 +552,22 @@ test_expect_success '"add" in bare repo invokes post-checkout hook' '
 	test_cmp hook.expect goozy/hook.actual
 '
 
+test_expect_success '"add" an existing but missing worktree' '
+	git worktree add --detach pneu &&
+	test_must_fail git worktree add --detach pneu &&
+	rm -fr pneu &&
+	test_must_fail git worktree add --detach pneu &&
+	git worktree add --force --detach pneu
+'
+
+test_expect_success '"add" an existing locked but missing worktree' '
+	git worktree add --detach gnoo &&
+	git worktree lock gnoo &&
+	test_when_finished "git worktree unlock gnoo || :" &&
+	rm -fr gnoo &&
+	test_must_fail git worktree add --detach gnoo &&
+	test_must_fail git worktree add --force --detach gnoo &&
+	git worktree add --force --force --detach gnoo
+'
+
 test_done

t/t2028-worktree-move.sh

@@ -98,6 +98,20 @@ test_expect_success 'move worktree to another dir' '
 	test_cmp expected2 actual2
 '
 
+test_expect_success 'move locked worktree (force)' '
+	test_when_finished "
+		git worktree unlock flump || :
+		git worktree remove flump || :
+		git worktree unlock ploof || :
+		git worktree remove ploof || :
+		" &&
+	git worktree add --detach flump &&
+	git worktree lock flump &&
+	test_must_fail git worktree move flump ploof" &&
+	test_must_fail git worktree move --force flump ploof" &&
+	git worktree move --force --force flump ploof
+'
+
 test_expect_success 'remove main worktree' '
 	test_must_fail git worktree remove .
 '
@@ -141,4 +155,34 @@ test_expect_success 'NOT remove missing-but-locked worktree' '
 	test_path_is_dir .git/worktrees/gone-but-locked
 '
 
+test_expect_success 'proper error when worktree not found' '
+	for i in noodle noodle/bork
+	do
+		test_must_fail git worktree lock $i 2>err &&
+		test_i18ngrep "not a working tree" err || return 1
+	done
+'
+
+test_expect_success 'remove locked worktree (force)' '
+	git worktree add --detach gumby &&
+	test_when_finished "git worktree remove gumby || :" &&
+	git worktree lock gumby &&
+	test_when_finished "git worktree unlock gumby || :" &&
+	test_must_fail git worktree remove gumby &&
+	test_must_fail git worktree remove --force gumby &&
+	git worktree remove --force --force gumby
+'
+
+test_expect_success 'remove cleans up .git/worktrees when empty' '
+	git init moog &&
+	(
+		cd moog &&
+		test_commit bim &&
+		git worktree add --detach goom &&
+		test_path_exists .git/worktrees &&
+		git worktree remove goom &&
+		test_path_is_missing .git/worktrees
+	)
+'
+
 test_done

worktree.c

@@ -217,7 +217,11 @@ struct worktree *find_worktree(struct worktree **list,
 
 	if (prefix)
 		arg = to_free = prefix_filename(prefix, arg);
-	path = real_pathdup(arg, 1);
+	path = real_pathdup(arg, 0);
+	if (!path) {
+		free(to_free);
+		return NULL;
+	}
 	for (; *list; list++)
 		if (!fspathcmp(path, real_path((*list)->path)))
 			break;