worktree add -B: do the checkout test before update branch

If --force is not given but -B is, we should not proceed if the given branch is already checked out elsewhere. add_worktree() has this test, but it kicks in too late when "git branch --force" is already executed. As a result, even though we correctly refuse to create a new worktree, we have already updated the branch and mess up the other checkout. Repeat the die_if_checked_out() test again for this specific case before "git branch" runs. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Nguyễn Thái Ngọc Duy committed Feb 15, 2016 at 20:35 UTC beb6f24beef67f6f825c8c99e408f67d23b784d4
2 files changed +17 -1
builtin/worktree.c
+10 -1
@@ -334,9 +334,18 @@ static int add(int ac, const char **av, const char *prefix)
334 branch = ac < 2 ? "HEAD" : av[1];
335
336 opts.force_new_branch = !!new_branch_force;
337 - if (opts.force_new_branch)
337 + if (opts.force_new_branch) {
338 + struct strbuf symref = STRBUF_INIT;
339 +
340 opts.new_branch = new_branch_force;
341
342 + if (!opts.force &&
343 + !strbuf_check_branch_ref(&symref, opts.new_branch) &&
344 + ref_exists(symref.buf))
345 + die_if_checked_out(symref.buf);
346 + strbuf_release(&symref);
347 + }
348 +
349 if (ac < 2 && !opts.new_branch && !opts.detach) {
350 int n;
351 const char *s = worktree_basename(path, &n);
t/t2025-worktree-add.sh
+7
@@ -193,6 +193,13 @@ test_expect_success '"add" -B/--detach mutually exclusive' '
193 test_must_fail git worktree add -B poodle --detach bamboo master
194 '
195
196 +test_expect_success '"add -B" fails if the branch is checked out' '
197 + git rev-parse newmaster >before &&
198 + test_must_fail git worktree add -B newmaster bamboo master &&
199 + git rev-parse newmaster >after &&
200 + test_cmp before after
201 +'
202 +
203 test_expect_success 'add -B' '
204 git worktree add -B poodle bamboo2 master^ &&
205 git -C bamboo2 symbolic-ref HEAD >actual &&