git-commit-vandalism/t/t2024-checkout-dwim.sh
Alexandr Miloslavskiy fa74180d08 checkout: don't revert file on ambiguous tracking branches
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_-_@alter.siamese.dyndns.org/
[2] Commit ad8d5104 ("checkout: add advice for ambiguous "checkout <branch>"", 2018-06-05)
    https://public-inbox.org/git/20180502105452.17583-1-avarab@gmail.com/
[3] Commit be4908f1 ("checkout: disambiguate dwim tracking branches and local files", 2018-11-13)
    https://public-inbox.org/git/20181110120707.25846-1-pclouds@gmail.com/

Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-07 13:15:38 -08:00

337 lines
9.1 KiB
Bash
Executable File

#!/bin/sh
test_description='checkout <branch>
Ensures that checkout on an unborn branch does what the user expects'
. ./test-lib.sh
# Is the current branch "refs/heads/$1"?
test_branch () {
printf "%s\n" "refs/heads/$1" >expect.HEAD &&
git symbolic-ref HEAD >actual.HEAD &&
test_cmp expect.HEAD actual.HEAD
}
# Is branch "refs/heads/$1" set to pull from "$2/$3"?
test_branch_upstream () {
printf "%s\n" "$2" "refs/heads/$3" >expect.upstream &&
{
git config "branch.$1.remote" &&
git config "branch.$1.merge"
} >actual.upstream &&
test_cmp expect.upstream actual.upstream
}
status_uno_is_clean () {
git status -uno --porcelain >status.actual &&
test_must_be_empty status.actual
}
test_expect_success 'setup' '
test_commit my_master &&
git init repo_a &&
(
cd repo_a &&
test_commit a_master &&
git checkout -b foo &&
test_commit a_foo &&
git checkout -b bar &&
test_commit a_bar &&
git checkout -b ambiguous_branch_and_file &&
test_commit a_ambiguous_branch_and_file
) &&
git init repo_b &&
(
cd repo_b &&
test_commit b_master &&
git checkout -b foo &&
test_commit b_foo &&
git checkout -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 &&
git config remote.repo_b.fetch \
"+refs/heads/*:refs/remotes/other_b/*" &&
git fetch --all
'
test_expect_success 'checkout of non-existing branch fails' '
git checkout -B master &&
test_might_fail git branch -D xyzzy &&
test_must_fail git checkout xyzzy &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/xyzzy &&
test_branch master
'
test_expect_success 'checkout of branch from multiple remotes fails #1' '
git checkout -B master &&
test_might_fail git branch -D foo &&
test_must_fail git checkout foo &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/foo &&
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 &&
test_must_fail git checkout foo 2>stderr &&
test_branch master &&
status_uno_is_clean &&
test_i18ngrep "^hint: " stderr &&
test_must_fail git -c advice.checkoutAmbiguousRemoteBranchName=false \
checkout foo 2>stderr &&
test_branch master &&
status_uno_is_clean &&
test_i18ngrep ! "^hint: " stderr
'
test_expect_success PERL 'checkout -p with multiple remotes does not print advice' '
git checkout -B master &&
test_might_fail git branch -D foo &&
git checkout -p foo 2>stderr &&
test_i18ngrep ! "^hint: " stderr &&
status_uno_is_clean
'
test_expect_success 'checkout of branch from multiple remotes succeeds with checkout.defaultRemote #1' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D foo &&
git -c checkout.defaultRemote=repo_a checkout foo &&
status_uno_is_clean &&
test_branch foo &&
test_cmp_rev remotes/repo_a/foo HEAD &&
test_branch_upstream foo repo_a foo
'
test_expect_success 'checkout of branch from a single remote succeeds #1' '
git checkout -B master &&
test_might_fail git branch -D bar &&
git checkout bar &&
status_uno_is_clean &&
test_branch bar &&
test_cmp_rev remotes/repo_a/bar HEAD &&
test_branch_upstream bar repo_a bar
'
test_expect_success 'checkout of branch from a single remote succeeds #2' '
git checkout -B master &&
test_might_fail git branch -D baz &&
git checkout baz &&
status_uno_is_clean &&
test_branch baz &&
test_cmp_rev remotes/other_b/baz HEAD &&
test_branch_upstream baz repo_b baz
'
test_expect_success '--no-guess suppresses branch auto-vivification' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D bar &&
test_must_fail git checkout --no-guess bar &&
test_must_fail git rev-parse --verify refs/heads/bar &&
test_branch master
'
test_expect_success 'setup more remotes with unconventional refspecs' '
git checkout -B master &&
status_uno_is_clean &&
git init repo_c &&
(
cd repo_c &&
test_commit c_master &&
git checkout -b bar &&
test_commit c_bar &&
git checkout -b spam &&
test_commit c_spam
) &&
git init repo_d &&
(
cd repo_d &&
test_commit d_master &&
git checkout -b baz &&
test_commit d_baz &&
git checkout -b eggs &&
test_commit d_eggs
) &&
git remote add repo_c repo_c &&
git config remote.repo_c.fetch \
"+refs/heads/*:refs/remotes/extra_dir/repo_c/extra_dir/*" &&
git remote add repo_d repo_d &&
git config remote.repo_d.fetch \
"+refs/heads/*:refs/repo_d/*" &&
git fetch --all
'
test_expect_success 'checkout of branch from multiple remotes fails #2' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D bar &&
test_must_fail git checkout bar &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/bar &&
test_branch master
'
test_expect_success 'checkout of branch from multiple remotes fails #3' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D baz &&
test_must_fail git checkout baz &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/baz &&
test_branch master
'
test_expect_success 'checkout of branch from a single remote succeeds #3' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D spam &&
git checkout spam &&
status_uno_is_clean &&
test_branch spam &&
test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
test_branch_upstream spam repo_c spam
'
test_expect_success 'checkout of branch from a single remote succeeds #4' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D eggs &&
git checkout eggs &&
status_uno_is_clean &&
test_branch eggs &&
test_cmp_rev refs/repo_d/eggs HEAD &&
test_branch_upstream eggs repo_d eggs
'
test_expect_success 'checkout of branch with a file having the same name fails' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D spam &&
>spam &&
test_must_fail git checkout spam &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/spam &&
test_branch master
'
test_expect_success 'checkout of branch with a file in subdir having the same name fails' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D spam &&
>spam &&
mkdir sub &&
mv spam sub/spam &&
test_must_fail git -C sub checkout spam &&
status_uno_is_clean &&
test_must_fail git rev-parse --verify refs/heads/spam &&
test_branch master
'
test_expect_success 'checkout <branch> -- succeeds, even if a file with the same name exists' '
git checkout -B master &&
status_uno_is_clean &&
test_might_fail git branch -D spam &&
>spam &&
git checkout spam -- &&
status_uno_is_clean &&
test_branch spam &&
test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
test_branch_upstream spam repo_c spam
'
test_expect_success 'loosely defined local base branch is reported correctly' '
git checkout master &&
status_uno_is_clean &&
git branch strict &&
git branch loose &&
git commit --allow-empty -m "a bit more" &&
test_config branch.strict.remote . &&
test_config branch.loose.remote . &&
test_config branch.strict.merge refs/heads/master &&
test_config branch.loose.merge master &&
git checkout strict | sed -e "s/strict/BRANCHNAME/g" >expect &&
status_uno_is_clean &&
git checkout loose | sed -e "s/loose/BRANCHNAME/g" >actual &&
status_uno_is_clean &&
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