checkout: disambiguate dwim tracking branches and local files
When checkout dwim is added in [1], it is restricted to only dwim when
certain conditions are met and fall back to default checkout behavior
otherwise. It turns out falling back could be confusing. One of the
conditions to turn
git checkout frotz
to
git checkout -b frotz origin/frotz
is that frotz must not exist as a file. But when the user comes to
expect "git checkout frotz" to create the branch "frotz" and there
happens to be a file named "frotz", git's silently reverting "frotz"
file content is not helping. This is reported in Git mailing list [2]
and even used as an example of "Git is bad" elsewhere [3].
We normally try to do the right thing, but when there are multiple
"right things" to do, it's best to leave it to the user to decide.
Check this case, ask the user to to disambiguate:
- "git checkout -- foo" will check out path "foo"
- "git checkout foo --" will dwim and create branch "foo" [4]
For users who do not want dwim, use --no-guess. It's useless in this
particular case because "git checkout --no-guess foo --" will just
fail. But it could be used by scripts.
[1] 70c9ac2f19 (DWIM "git checkout frotz" to "git checkout -b frotz
origin/frotz" - 2009-10-18)
[2] https://public-inbox.org/git/CACsJy8B2TVr1g+k+eSQ=pBEO3WN4_LtgLo9gpur8X7Z9GOFL_A@mail.gmail.com/
[3] https://news.ycombinator.com/item?id=18230655
[4] a047fafc78 (checkout: allow dwim for branch creation for "git
checkout $branch --" - 2013-10-18)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 801de2f..6acc3d9 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -276,6 +276,10 @@
Just like linkgit:git-submodule[1], this will detach the
submodules HEAD.
+--no-guess::
+ Do not attempt to create a branch if a remote tracking branch
+ of the same name exists.
+
<branch>::
Branch to checkout; if it refers to a branch (i.e., a name that,
when prepended with "refs/heads/", is a valid ref), then that
diff --git a/builtin/checkout.c b/builtin/checkout.c
index acdafc6..4744e8c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1079,9 +1079,12 @@
*/
int recover_with_dwim = dwim_new_local_branch_ok;
- if (!has_dash_dash &&
- (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
+ int could_be_checkout_paths = !has_dash_dash &&
+ check_filename(opts->prefix, arg);
+
+ if (!has_dash_dash && !no_wildcard(arg))
recover_with_dwim = 0;
+
/*
* Accept "git checkout foo" and "git checkout foo --"
* as candidates for dwim.
@@ -1094,6 +1097,10 @@
const char *remote = unique_tracking_name(arg, rev,
dwim_remotes_matched);
if (remote) {
+ if (could_be_checkout_paths)
+ die(_("'%s' could be both a local file and a tracking branch.\n"
+ "Please use -- (and optionally --no-guess) to disambiguate"),
+ arg);
*new_branch = arg;
arg = remote;
/* DWIMmed to create local branch, case (3).(b) */
@@ -1228,7 +1235,7 @@
struct checkout_opts opts;
struct branch_info new_branch_info;
char *conflict_style = NULL;
- int dwim_new_local_branch = 1;
+ int dwim_new_local_branch, no_dwim_new_local_branch = 0;
int dwim_remotes_matched = 0;
struct option options[] = {
OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
@@ -1258,8 +1265,8 @@
OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
N_("do not limit pathspecs to sparse entries only")),
- OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
- N_("second guess 'git checkout <no-such-branch>'")),
+ OPT_BOOL(0, "no-guess", &no_dwim_new_local_branch,
+ N_("do not second guess 'git checkout <no-such-branch>'")),
OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
N_("do not check if another worktree is holding the given ref")),
{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
@@ -1282,6 +1289,7 @@
argc = parse_options(argc, argv, prefix, options, checkout_usage,
PARSE_OPT_KEEP_DASHDASH);
+ dwim_new_local_branch = !no_dwim_new_local_branch;
if (opts.show_progress < 0) {
if (opts.quiet)
opts.show_progress = 0;
diff --git a/t/t2024-checkout-dwim.sh b/t/t2024-checkout-dwim.sh
index 69b6774..fa0718c 100755
--- a/t/t2024-checkout-dwim.sh
+++ b/t/t2024-checkout-dwim.sh
@@ -278,4 +278,35 @@
test_cmp expect actual
'
+test_expect_success 'reject when arg could be part of dwim branch' '
+ git remote add foo file://non-existent-place &&
+ git update-ref refs/remotes/foo/dwim-arg HEAD &&
+ echo foo >dwim-arg &&
+ git add dwim-arg &&
+ echo bar >dwim-arg &&
+ test_must_fail git checkout dwim-arg &&
+ test_must_fail git rev-parse refs/heads/dwim-arg -- &&
+ grep bar dwim-arg
+'
+
+test_expect_success 'disambiguate dwim branch and checkout path (1)' '
+ git update-ref refs/remotes/foo/dwim-arg1 HEAD &&
+ echo foo >dwim-arg1 &&
+ git add dwim-arg1 &&
+ echo bar >dwim-arg1 &&
+ git checkout -- dwim-arg1 &&
+ test_must_fail git rev-parse refs/heads/dwim-arg1 -- &&
+ grep foo dwim-arg1
+'
+
+test_expect_success 'disambiguate dwim branch and checkout path (2)' '
+ git update-ref refs/remotes/foo/dwim-arg2 HEAD &&
+ echo foo >dwim-arg2 &&
+ git add dwim-arg2 &&
+ echo bar >dwim-arg2 &&
+ git checkout dwim-arg2 -- &&
+ git rev-parse refs/heads/dwim-arg2 -- &&
+ grep bar dwim-arg2
+'
+
test_done
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 175f83d..aa92f85 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1434,7 +1434,8 @@
--ignore-other-worktrees Z
--recurse-submodules Z
--progress Z
- --no-quiet Z
+ --guess Z
+ --no-guess Z
--no-... Z
EOF
'
