git-commit-vandalism/t/t3429-rebase-edit-todo.sh

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#!/bin/sh
test_description='rebase should reread the todo file if an exec modifies it'
. ./test-lib.sh
. "$TEST_DIRECTORY"/lib-rebase.sh
test_expect_success 'setup' '
test_commit first file &&
test_commit second file &&
test_commit third file
'
test_expect_success 'rebase exec modifies rebase-todo' '
todo=.git/rebase-merge/git-rebase-todo &&
git rebase HEAD -x "echo exec touch F >>$todo" &&
test -e F
'
test_expect_success 'loose object cache vs re-reading todo list' '
rebase -i: demonstrate obscure loose object cache bug We specifically support `exec` commands in `git rebase -i`'s todo lists to rewrite the very same todo list. Of course, we need to validate that todo list when re-reading it. It is also totally legitimate to extend the todo list by `pick` lines using short names of commits that were created only after the rebase started. And this is where the loose object cache interferes with this feature: if *some* loose object was read whose hash shares the same first two digits with a commit that was not yet created when that loose object was created, then we fail to find that new commit by its short name in `get_oid()`, and the interactive rebase fails with an obscure error message like: error: invalid line 1: pick 6568fef error: please fix this using 'git rebase --edit-todo'. Let's first demonstrate that this is actually a bug in a new regression test, in a separate commit so that other developers who do not believe me can cherry-pick it to confirm the problem. This new regression test generates two commits whose hashes share the first two hex digits (so that their corresponding loose objects live in the same subdirectory of .git/objects/, and are therefore supposed to be in the same loose object cache bin). It then picks the first, to make sure that the loose object cache is initialized and cached that object directory, then generates the second commit and picks it, too. Since the commit was generated in a different process than the sequencer that wants to pick it, the loose object cache had no chance of being updated in the meantime. Technically, we would need only one `exec` command in this regression test case, but for ease of implementation, it uses a pseudo-recursive call to the same script. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-13 11:16:31 +01:00
GIT_REBASE_TODO=.git/rebase-merge/git-rebase-todo &&
export GIT_REBASE_TODO &&
write_script append-todo.sh <<-\EOS &&
# For values 5 and 6, this yields SHA-1s with the same first two digits
echo "pick $(git rev-parse --short \
$(printf "%s\\n" \
"tree $EMPTY_TREE" \
"author A U Thor <author@example.org> $1 +0000" \
"committer A U Thor <author@example.org> $1 +0000" \
"" \
"$1" |
git hash-object -t commit -w --stdin))" >>$GIT_REBASE_TODO
shift
test -z "$*" ||
echo "exec $0 $*" >>$GIT_REBASE_TODO
EOS
git rebase HEAD -x "./append-todo.sh 5 6"
'
test_expect_success 'todo is re-read after reword and squash' '
write_script reword-editor.sh <<-\EOS &&
GIT_SEQUENCE_EDITOR="echo \"exec echo $(cat file) >>actual\" >>" \
git rebase --edit-todo
EOS
test_write_lines first third >expected &&
set_fake_editor &&
GIT_SEQUENCE_EDITOR="$EDITOR" FAKE_LINES="reword 1 squash 2 fixup 3" \
GIT_EDITOR=./reword-editor.sh git rebase -i --root third &&
test_cmp expected actual
'
sequencer: don't re-read todo for revert and cherry-pick When 'git revert' or 'git cherry-pick --edit' is invoked with multiple commits, then after editing the first commit message is finished both these commands should continue with processing the second commit and launch another editor for its commit message, assuming there are no conflicts, of course. Alas, this inadvertently changed with commit a47ba3c777 (rebase -i: check for updated todo after squash and reword, 2019-08-19): after editing the first commit message is finished, both 'git revert' and 'git cherry-pick --edit' exit with error, claiming that "nothing to commit, working tree clean". The reason for the changed behaviour is twofold: - Prior to a47ba3c777 the up-to-dateness of the todo list file was only checked after 'exec' instructions, and that commit moved those checks to the common code path. The intention was that this check should be performed after instructions spawning an editor ('squash' and 'reword') as well, so the ongoing 'rebase -i' notices when the user runs a 'git rebase --edit-todo' while squashing/rewording a commit message. However, as it happened that check is now performed even after 'revert' and 'pick' instructions when they involved editing the commit message. And 'revert' by default while 'pick' optionally (with 'git cherry-pick --edit') involves editing the commit message. - When invoking 'git revert' or 'git cherry-pick --edit' with multiple commits they don't read a todo list file but assemble the todo list in memory, thus the associated stat data used to check whether the file has been updated is all zeroed out initially. Then the sequencer writes all instructions (including the very first) to the todo file, executes the first 'revert/pick' instruction, and after the user finished editing the commit message the changes of a47ba3c777 kick in, and it checks whether the todo file has been modified. The initial all-zero stat data obviously differs from the todo file's current stat data, so the sequencer concludes that the file has been modified. Technically it is not wrong, of course, because the file just has been written indeed by the sequencer itself, though the file's contents still match what the sequencer was invoked with in the beginning. Consequently, after re-reading the todo file the sequencer executes the same first instruction _again_, thus ending up in that "nothing to commit" situation. The todo list was never meant to be edited during multi-commit 'git revert' or 'cherry-pick' operations, so perform that "has the todo file been modified" check only when the sequencer was invoked as part of an interactive rebase. Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-23 18:20:46 +01:00
test_expect_success 're-reading todo doesnt interfere with revert --edit' '
git reset --hard third &&
git revert --edit third second &&
cat >expect <<-\EOF &&
Revert "second"
Revert "third"
third
second
first
EOF
git log --format="%s" >actual &&
test_cmp expect actual
'
test_expect_success 're-reading todo doesnt interfere with cherry-pick --edit' '
git reset --hard first &&
git cherry-pick --edit second third &&
cat >expect <<-\EOF &&
third
second
first
EOF
git log --format="%s" >actual &&
test_cmp expect actual
'
test_done