checkout: improve error messages for -b with extra argument

When we try to create a branch "foo" based on "origin/master" and give git commit -b an extra unsupported argument "bar", it confusingly reports: $ git checkout -b foo origin/master bar fatal: 'bar' is not a commit and a branch 'foo' cannot be created from it $ git checkout --track -b foo origin/master bar fatal: 'bar' is not a commit and a branch 'foo' cannot be created from it That's wrong, because it very well understands that "origin/master" is supposed to be the start point for the new branch and not "bar". Check if we got a commit and show more fitting messages in that case instead: $ git checkout -b foo origin/master bar fatal: Cannot update paths and switch to branch 'foo' at the same time. $ git checkout --track -b foo origin/master bar fatal: '--track' cannot be used with updating paths Original-patch-by: Jeff King <peff@peff.net> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

René Scharfe committed May 24, 2020 at 09:23 UTC bb2198fb91ada94cfc6f8ec81b9dadcf3959fe10

3 files changed +3 -3

builtin/checkout.c

+1 -1

@@ -1689,7 +1689,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,

1689 * Try to give more helpful suggestion.

1690 * new_branch && argc > 1 will be caught later.

1691 */

1692 - if (opts->new_branch && argc == 1)

1692 + if (opts->new_branch && argc == 1 && !new_branch_info.commit)

1693 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),

1694 argv[0], opts->new_branch);

1695

t/t2018-checkout-branch.sh

+1 -1

@@ -265,7 +265,7 @@ test_expect_success 'checkout -b rejects an invalid start point' '

265 test_i18ngrep "is not a commit" err

266 '

267

268 -test_expect_failure 'checkout -b rejects an extra path argument' '

268 +test_expect_success 'checkout -b rejects an extra path argument' '

269 test_must_fail git checkout -b branch5 branch1 file1 2>err &&

270 test_i18ngrep "Cannot update paths and switch to branch" err

271 '

t/t2027-checkout-track.sh

+1 -1

@@ -16,7 +16,7 @@ test_expect_success 'checkout --track -b creates a new tracking branch' '

16 test $(git config --get branch.branch1.merge) = refs/heads/master

17 '

19 -test_expect_failure 'checkout --track -b rejects an extra path argument' '

19 +test_expect_success 'checkout --track -b rejects an extra path argument' '

20 test_must_fail git checkout --track -b branch2 master one.t 2>err &&

21 test_i18ngrep "cannot be used with updating paths" err

22 '