From: Alexandr Miloslavskiy <alexandr.miloslavskiy@xxxxxxxxxxx>
For easier understanding, here are the existing good scenarios:
1) Have *no* file 'foo', *no* local branch 'foo' and a *single*
remote branch 'foo'
2) `git checkout foo` will create local branch foo, see [1]
and
1) Have *a* file 'foo', *no* local branch 'foo' and a *single*
remote branch 'foo'
2) `git checkout foo` will complain, see [3]
This patch prevents the following scenario:
1) Have *a* file 'foo', *no* local branch 'foo' and *multiple*
remote branches 'foo'
2) `git checkout foo` will successfully... revert contents of
file `foo`!
That is, adding another remote suddenly changes behavior significantly,
which is a surprise at best and could go unnoticed by user at worst.
Please see [3] which gives some real world complaints.
To my understanding, fix in [3] overlooked the case of multiple remotes,
and the whole behavior of falling back to reverting file was never
intended:
[1] introduces the unexpected behavior. Before, there was fallback
from not-a-ref to pathspec. This is reasonable fallback. After, there
is another fallback from ambiguous-remote to pathspec. I understand
that it was a copy&paste oversight.
[2] noticed the unexpected behavior but chose to semi-document it
instead of forbidding, because the goal of the patch series was
focused on something else.
[3] adds `die()` when there is ambiguity between branch and file. The
case of multiple tracking branches is seemingly overlooked.
The new behavior: if there is no local branch and multiple remote
candidates, just die() and don't try reverting file whether it
exists (prevents surprise) or not (improves error message).
[1] Commit 70c9ac2f ("DWIM "git checkout frotz" to "git checkout -b frotz origin/frotz"" 2009-10-18)
https://public-inbox.org/git/7vaazpxha4.fsf_-_@xxxxxxxxxxxxxxxxxxxxxxxx/
[2] Commit ad8d5104 ("checkout: add advice for ambiguous "checkout <branch>"", 2018-06-05)
https://public-inbox.org/git/20180502105452.17583-1-avarab@xxxxxxxxx/
[3] Commit be4908f1 ("checkout: disambiguate dwim tracking branches and local files", 2018-11-13)
https://public-inbox.org/git/20181110120707.25846-1-pclouds@xxxxxxxxx/
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@xxxxxxxxxxx>
---
builtin/checkout.c | 56 ++++++++++++++++++----------------------
t/t2024-checkout-dwim.sh | 28 ++++++++++++++++++--
2 files changed, 51 insertions(+), 33 deletions(-)
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f832040e94..5c41645c7d 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1117,10 +1117,10 @@ static void setup_new_branch_info_and_source_tree(
static const char *parse_remote_branch(const char *arg,
struct object_id *rev,
- int could_be_checkout_paths,
- int *dwim_remotes_matched)
+ int could_be_checkout_paths)
{
- const char *remote = unique_tracking_name(arg, rev, dwim_remotes_matched);
+ int num_matches = 0;
+ const char *remote = unique_tracking_name(arg, rev, &num_matches);
if (remote && could_be_checkout_paths) {
die(_("'%s' could be both a local file and a tracking branch.\n"
@@ -1128,6 +1128,22 @@ static const char *parse_remote_branch(const char *arg,
arg);
}
+ if (!remote && num_matches > 1) {
+ if (advice_checkout_ambiguous_remote_branch_name) {
+ advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
+ "you can do so by fully qualifying the name with the --track option:\n"
+ "\n"
+ " git checkout --track origin/<name>\n"
+ "\n"
+ "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
+ "one remote, e.g. the 'origin' remote, consider setting\n"
+ "checkout.defaultRemote=origin in your config."));
+ }
+
+ die(_("'%s' matched multiple (%d) remote tracking branches"),
+ arg, num_matches);
+ }
+
return remote;
}
@@ -1135,8 +1151,7 @@ static int parse_branchname_arg(int argc, const char **argv,
int dwim_new_local_branch_ok,
struct branch_info *new_branch_info,
struct checkout_opts *opts,
- struct object_id *rev,
- int *dwim_remotes_matched)
+ struct object_id *rev)
{
const char **new_branch = &opts->new_branch;
int argcount = 0;
@@ -1242,8 +1257,7 @@ static int parse_branchname_arg(int argc, const char **argv,
if (recover_with_dwim) {
const char *remote = parse_remote_branch(arg, rev,
- could_be_checkout_paths,
- dwim_remotes_matched);
+ could_be_checkout_paths);
if (remote) {
*new_branch = arg;
arg = remote;
@@ -1509,7 +1523,6 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
const char * const usagestr[])
{
struct branch_info new_branch_info;
- int dwim_remotes_matched = 0;
int parseopt_flags = 0;
memset(&new_branch_info, 0, sizeof(new_branch_info));
@@ -1617,8 +1630,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
opts->track == BRANCH_TRACK_UNSPECIFIED &&
!opts->new_branch;
int n = parse_branchname_arg(argc, argv, dwim_ok,
- &new_branch_info, opts, &rev,
- &dwim_remotes_matched);
+ &new_branch_info, opts, &rev);
argv += n;
argc -= n;
} else if (!opts->accept_ref && opts->from_treeish) {
@@ -1695,28 +1707,10 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
}
UNLEAK(opts);
- if (opts->patch_mode || opts->pathspec.nr) {
- int ret = checkout_paths(opts, new_branch_info.name);
- if (ret && dwim_remotes_matched > 1 &&
- advice_checkout_ambiguous_remote_branch_name)
- advise(_("'%s' matched more than one remote tracking branch.\n"
- "We found %d remotes with a reference that matched. So we fell back\n"
- "on trying to resolve the argument as a path, but failed there too!\n"
- "\n"
- "If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
- "you can do so by fully qualifying the name with the --track option:\n"
- "\n"
- " git checkout --track origin/<name>\n"
- "\n"
- "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
- "one remote, e.g. the 'origin' remote, consider setting\n"
- "checkout.defaultRemote=origin in your config."),
- argv[0],
- dwim_remotes_matched);
- return ret;
- } else {
+ if (opts->patch_mode || opts->pathspec.nr)
+ return checkout_paths(opts, new_branch_info.name);
+ else
return checkout_branch(opts, &new_branch_info);
- }
}
int cmd_checkout(int argc, const char **argv, const char *prefix)
diff --git a/t/t2024-checkout-dwim.sh b/t/t2024-checkout-dwim.sh
index fa0718c730..accfa9aa4b 100755
--- a/t/t2024-checkout-dwim.sh
+++ b/t/t2024-checkout-dwim.sh
@@ -37,7 +37,9 @@ test_expect_success 'setup' '
git checkout -b foo &&
test_commit a_foo &&
git checkout -b bar &&
- test_commit a_bar
+ test_commit a_bar &&
+ git checkout -b ambiguous_branch_and_file &&
+ test_commit a_ambiguous_branch_and_file
) &&
git init repo_b &&
(
@@ -46,7 +48,9 @@ test_expect_success 'setup' '
git checkout -b foo &&
test_commit b_foo &&
git checkout -b baz &&
- test_commit b_baz
+ test_commit b_baz &&
+ git checkout -b ambiguous_branch_and_file &&
+ test_commit b_ambiguous_branch_and_file
) &&
git remote add repo_a repo_a &&
git remote add repo_b repo_b &&
@@ -75,6 +79,26 @@ test_expect_success 'checkout of branch from multiple remotes fails #1' '
test_branch master
'
+test_expect_success 'when arg matches multiple remotes, do not fallback to interpreting as pathspec' '
+ # create a file with name matching remote branch name
+ git checkout -b t_ambiguous_branch_and_file &&
+ >ambiguous_branch_and_file &&
+ git add ambiguous_branch_and_file &&
+ git commit -m "ambiguous_branch_and_file" &&
+
+ # modify file to verify that it will not be touched by checkout
+ test_when_finished "git checkout -- ambiguous_branch_and_file" &&
+ echo "file contents" >ambiguous_branch_and_file &&
+ cp ambiguous_branch_and_file expect &&
+
+ test_must_fail git checkout ambiguous_branch_and_file 2>err &&
+
+ test_i18ngrep "matched multiple (2) remote tracking branches" err &&
+
+ # file must not be altered
+ test_cmp expect ambiguous_branch_and_file
+'
+
test_expect_success 'checkout of branch from multiple remotes fails with advice' '
git checkout -B master &&
test_might_fail git branch -D foo &&
--
gitgitgadget
