git-commit-vandalism/t/lib-rebase.sh
Phillip Wood baf8ec8d3a rebase -r: don't write .git/MERGE_MSG when fast-forwarding
When fast-forwarding we do not create a new commit so .git/MERGE_MSG
is not removed and can end up seeding the message of a commit made
after the rebase has finished. Avoid writing .git/MERGE_MSG when we
are fast-forwarding by writing the file after the fast-forward
checks. Note that there are no changes to the fast-forward code, it is
simply moved.

Note that the way this change is implemented means we no longer write
the author script when fast-forwarding either. I believe this is safe
for the reasons below but it is a departure from what we do when
fast-forwarding a non-merge commit. If we reword the merge then 'git
commit --amend' will keep the authorship of the commit we're rewording
as it ignores GIT_AUTHOR_* unless --reset-author is passed. It will
also export the correct GIT_AUTHOR_* variables to any hooks and we
already test the authorship of the reworded commit. If we are not
rewording then we no longer call spilt_ident() which means we are no
longer checking the commit author header looks sane. However this is
what we already do when fast-forwarding non-merge commits in
skip_unnecessary_picks() so I don't think we're breaking any promises
by not checking the author here.

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-23 09:36:30 -07:00

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# Helper functions used by interactive rebase tests.
# After setting the fake editor with this function, you can
#
# - override the commit message with $FAKE_COMMIT_MESSAGE
# - amend the commit message with $FAKE_COMMIT_AMEND
# - copy the original commit message to a file with $FAKE_MESSAGE_COPY
# - check that non-commit messages have a certain line count with $EXPECT_COUNT
# - check the commit count in the commit message header with $EXPECT_HEADER_COUNT
# - rewrite a rebase -i script as directed by $FAKE_LINES.
# $FAKE_LINES consists of a sequence of words separated by spaces.
# The following word combinations are possible:
#
# "<lineno>" -- add a "pick" line with the SHA1 taken from the
# specified line.
#
# "<cmd> <lineno>" -- add a line with the specified command
# ("pick", "squash", "fixup"|"fixup_-C"|"fixup_-c", "edit", "reword" or "drop")
# and the SHA1 taken from the specified line.
#
# "_" -- add a space, like "fixup_-C" implies "fixup -C" and
# "exec_cmd_with_args" add an "exec cmd with args" line.
#
# "#" -- Add a comment line.
#
# ">" -- Add a blank line.
set_fake_editor () {
write_script fake-editor.sh <<-\EOF
case "$1" in
*/COMMIT_EDITMSG)
test -z "$EXPECT_HEADER_COUNT" ||
test "$EXPECT_HEADER_COUNT" = "$(sed -n '1s/^# This is a combination of \(.*\) commits\./\1/p' < "$1")" ||
exit
test -z "$FAKE_COMMIT_MESSAGE" || echo "$FAKE_COMMIT_MESSAGE" > "$1"
test -z "$FAKE_COMMIT_AMEND" || echo "$FAKE_COMMIT_AMEND" >> "$1"
test -z "$FAKE_MESSAGE_COPY" || cat "$1" >"$FAKE_MESSAGE_COPY"
exit
;;
esac
test -z "$EXPECT_COUNT" ||
test "$EXPECT_COUNT" = $(sed -e '/^#/d' -e '/^$/d' < "$1" | wc -l) ||
exit
test -z "$FAKE_LINES" && exit
grep -v '^#' < "$1" > "$1".tmp
rm -f "$1"
echo 'rebase -i script before editing:'
cat "$1".tmp
action=\&
for line in $FAKE_LINES; do
case $line in
pick|p|squash|s|fixup|f|edit|e|reword|r|drop|d|label|l|reset|r|merge|m)
action="$line";;
exec_*|x_*|break|b)
echo "$line" | sed 's/_/ /g' >> "$1";;
merge_*|fixup_*)
action=$(echo "$line" | sed 's/_/ /g');;
"#")
echo '# comment' >> "$1";;
">")
echo >> "$1";;
bad)
action="badcmd";;
fakesha)
test \& != "$action" || action=pick
echo "$action XXXXXXX False commit" >> "$1"
action=pick;;
*)
sed -n "${line}s/^[a-z][a-z]*/$action/p" < "$1".tmp >> "$1"
action=\&;;
esac
done
echo 'rebase -i script after editing:'
cat "$1"
EOF
test_set_editor "$(pwd)/fake-editor.sh"
}
# After set_cat_todo_editor, rebase -i will write the todo list (ignoring
# blank lines and comments) to stdout, and exit failure (so you should run
# it with test_must_fail). This can be used to verify the expected user
# experience, for todo list changes that do not affect the outcome of
# rebase; or as an extra check in addition to checking the outcome.
set_cat_todo_editor () {
write_script fake-editor.sh <<-\EOF
grep "^[^#]" "$1"
exit 1
EOF
test_set_editor "$(pwd)/fake-editor.sh"
}
# checks that the revisions in "$2" represent a linear range with the
# subjects in "$1"
test_linear_range () {
revlist_merges=$(git rev-list --merges "$2") &&
test -z "$revlist_merges" &&
expected=$1
set -- $(git log --reverse --format=%s "$2")
test "$expected" = "$*"
}
reset_rebase () {
test_might_fail git rebase --abort &&
git reset --hard &&
git clean -f
}
cherry_pick () {
git cherry-pick -n "$2" &&
git commit -m "$1" &&
git tag "$1"
}
revert () {
git revert -n "$2" &&
git commit -m "$1" &&
git tag "$1"
}
make_empty () {
git commit --allow-empty -m "$1" &&
git tag "$1"
}
# Call this (inside test_expect_success) at the end of a test file to
# check that no tests have changed editor related environment
# variables or config settings
test_editor_unchanged () {
# We're only interested in exported variables hence 'sh -c'
sh -c 'cat >actual <<-EOF
EDITOR=$EDITOR
FAKE_COMMIT_AMEND=$FAKE_COMMIT_AMEND
FAKE_COMMIT_MESSAGE=$FAKE_COMMIT_MESSAGE
FAKE_LINES=$FAKE_LINES
GIT_EDITOR=$GIT_EDITOR
GIT_SEQUENCE_EDITOR=$GIT_SEQUENCE_EDITOR
core.editor=$(git config core.editor)
sequence.editor=$(git config sequence.editor)
EOF'
cat >expect <<-\EOF
EDITOR=:
FAKE_COMMIT_AMEND=
FAKE_COMMIT_MESSAGE=
FAKE_LINES=
GIT_EDITOR=
GIT_SEQUENCE_EDITOR=
core.editor=
sequence.editor=
EOF
test_cmp expect actual
}
# Set up an editor for testing reword commands
# Checks that there are no uncommitted changes when rewording and that the
# todo-list is reread after each
set_reword_editor () {
>reword-actual &&
>reword-oid &&
# Check rewording keeps the original authorship
GIT_AUTHOR_NAME="Reword Author"
GIT_AUTHOR_EMAIL="reword.author@example.com"
GIT_AUTHOR_DATE=@123456
write_script reword-sequence-editor.sh <<-\EOF &&
todo="$(cat "$1")" &&
echo "exec git log -1 --pretty=format:'%an <%ae> %at%n%B%n' \
>>reword-actual" >"$1" &&
printf "%s\n" "$todo" >>"$1"
EOF
write_script reword-editor.sh <<-EOF &&
# Save the oid of the first reworded commit so we can check rebase
# fast-forwards to it. Also check that we do not write .git/MERGE_MSG
# when fast-forwarding
if ! test -s reword-oid
then
git rev-parse HEAD >reword-oid &&
if test -f .git/MERGE_MSG
then
echo 1>&2 "error: .git/MERGE_MSG exists"
exit 1
fi
fi &&
# There should be no uncommited changes
git diff --exit-code HEAD &&
# The todo-list should be re-read after a reword
GIT_SEQUENCE_EDITOR="\"$PWD/reword-sequence-editor.sh\"" \
git rebase --edit-todo &&
echo edited >>"\$1"
EOF
test_set_editor "$PWD/reword-editor.sh"
}
# Check the results of a rebase after calling set_reword_editor
# Pass the commits that were reworded in the order that they were picked
# Expects the first pick to be a fast-forward
check_reworded_commits () {
test_cmp_rev "$(cat reword-oid)" "$1^{commit}" &&
git log --format="%an <%ae> %at%n%B%nedited%n" --no-walk=unsorted "$@" \
>reword-expected &&
test_cmp reword-expected reword-actual &&
git log --format="%an <%ae> %at%n%B" -n $# --first-parent --reverse \
>reword-log &&
test_cmp reword-expected reword-log
}