git-commit-vandalism/t/t3904-stash-patch.sh

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#!/bin/sh
test_description='stash -p'
. ./lib-patch-mode.sh
if ! test_have_prereq PERL
then
skip_all='skipping stash -p tests, perl not available'
test_done
fi
test_expect_success 'setup' '
mkdir dir &&
echo parent > dir/foo &&
echo dummy > bar &&
echo committed > HEAD &&
git add bar dir/foo HEAD &&
git commit -m initial &&
test_tick &&
test_commit second dir/foo head &&
echo index > dir/foo &&
git add dir/foo &&
set_and_save_state bar bar_work bar_index &&
save_head
'
# note: order of files with unstaged changes: HEAD bar dir/foo
test_expect_success 'saying "n" does nothing' '
set_state HEAD HEADfile_work HEADfile_index &&
set_state dir/foo work index &&
test_write_lines n n n | test_must_fail git stash save -p &&
verify_state HEAD HEADfile_work HEADfile_index &&
verify_saved_state bar &&
verify_state dir/foo work index
'
test_expect_success 'git stash -p' '
test_write_lines y n y | git stash save -p &&
verify_state HEAD committed HEADfile_index &&
verify_saved_state bar &&
verify_state dir/foo head index &&
git reset --hard &&
git stash apply &&
verify_state HEAD HEADfile_work committed &&
verify_state bar dummy dummy &&
verify_state dir/foo work head
'
test_expect_success 'git stash -p --no-keep-index' '
set_state HEAD HEADfile_work HEADfile_index &&
set_state bar bar_work bar_index &&
set_state dir/foo work index &&
test_write_lines y n y | git stash save -p --no-keep-index &&
verify_state HEAD committed committed &&
verify_state bar bar_work dummy &&
verify_state dir/foo head head &&
git reset --hard &&
git stash apply --index &&
verify_state HEAD HEADfile_work HEADfile_index &&
verify_state bar dummy bar_index &&
verify_state dir/foo work index
'
test_expect_success 'git stash --no-keep-index -p' '
set_state HEAD HEADfile_work HEADfile_index &&
set_state bar bar_work bar_index &&
set_state dir/foo work index &&
test_write_lines y n y | git stash save --no-keep-index -p &&
verify_state HEAD committed committed &&
verify_state dir/foo head head &&
verify_state bar bar_work dummy &&
git reset --hard &&
git stash apply --index &&
verify_state HEAD HEADfile_work HEADfile_index &&
verify_state bar dummy bar_index &&
verify_state dir/foo work index
'
test_expect_success 'stash -p --no-keep-index -- <pathspec> does not unstage other files' '
set_state HEAD HEADfile_work HEADfile_index &&
set_state dir/foo work index &&
echo y | git stash push -p --no-keep-index -- HEAD &&
verify_state HEAD committed committed &&
verify_state dir/foo work index
'
test_expect_success 'none of this moved HEAD' '
verify_saved_head
'
stash -p: (partially) fix bug concerning split hunks When trying to stash part of the worktree changes by splitting a hunk and then only partially accepting the split bits and pieces, the user is presented with a rather cryptic error: error: patch failed: <file>:<line> error: test: patch does not apply Cannot remove worktree changes and the command would fail to stash the desired parts of the worktree changes (even if the `stash` ref was actually updated correctly). We even have a test case demonstrating that failure, carrying it for four years already. The explanation: when splitting a hunk, the changed lines are no longer separated by more than 3 lines (which is the amount of context lines Git's diffs use by default), but less than that. So when staging only part of the diff hunk for stashing, the resulting diff that we want to apply to the worktree in reverse will contain those changes to be dropped surrounded by three context lines, but since the diff is relative to HEAD rather than to the worktree, these context lines will not match. Example time. Let's assume that the file README contains these lines: We the people and the worktree added some lines so that it contains these lines instead: We are the kind people and the user tries to stash the line containing "are", then the command will internally stage this line to a temporary index file and try to revert the diff between HEAD and that index file. The diff hunk that `git stash` tries to revert will look somewhat like this: @@ -1776,3 +1776,4 We +are the people It is obvious, now, that the trailing context lines overlap with the part of the original diff hunk that the user did *not* want to stash. Keeping in mind that context lines in diffs serve the primary purpose of finding the exact location when the diff does not apply precisely (but when the exact line number in the file to be patched differs from the line number indicated in the diff), we work around this by reducing the amount of context lines: the diff was just generated. Note: this is not a *full* fix for the issue. Just as demonstrated in t3701's 'add -p works with pathological context lines' test case, there are ambiguities in the diff format. It is very rare in practice, of course, to encounter such repeated lines. The full solution for such cases would be to replace the approach of generating a diff from the stash and then applying it in reverse by emulating `git revert` (i.e. doing a 3-way merge). However, in `git stash -p` it would not apply to `HEAD` but instead to the worktree, which makes this non-trivial to implement as long as we also maintain a scripted version of `add -i`. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-08 20:52:34 +02:00
test_expect_success 'stash -p with split hunk' '
git reset --hard &&
cat >test <<-\EOF &&
aaa
bbb
ccc
EOF
git add test &&
git commit -m "initial" &&
cat >test <<-\EOF &&
aaa
added line 1
bbb
added line 2
ccc
EOF
printf "%s\n" s n y q |
git stash -p 2>error &&
test_must_be_empty error &&
grep "added line 1" test &&
! grep "added line 2" test
'
test_done