git/git-legacy-rebase.sh
Johannes Schindelin 8797f0f008 rebase --stat: fix when rebasing to an unrelated history
When rebasing to a commit history that has no common commits with the
current branch, there is no merge base. In diffstat mode, this means
that we cannot compare to the merge base, but we have to compare to the
empty tree instead.

Also, if running in verbose diffstat mode, we should not output

	Changes from <merge-base> to <onto>

as that does not make sense without any merge base.

Note: neither scripted nor built-in versoin of `git rebase` were
prepared for this situation well. We use this opportunity not only to
fix the bug(s), but also to make both versions' output consistent in
this instance. And add a regression test to keep this working in all
eternity.

Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-30 14:43:00 +09:00

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#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano.
#
SUBDIRECTORY_OK=Yes
OPTIONS_KEEPDASHDASH=
OPTIONS_STUCKLONG=t
OPTIONS_SPEC="\
git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] [<upstream>] [<branch>]
git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] --root [<branch>]
git rebase --continue | --abort | --skip | --edit-todo
--
Available options are
v,verbose! display a diffstat of what changed upstream
q,quiet! be quiet. implies --no-stat
autostash automatically stash/stash pop before and after
fork-point use 'merge-base --fork-point' to refine upstream
onto=! rebase onto given branch instead of upstream
r,rebase-merges? try to rebase merges instead of skipping them
p,preserve-merges! try to recreate merges instead of ignoring them
s,strategy=! use the given merge strategy
X,strategy-option=! pass the argument through to the merge strategy
no-ff! cherry-pick all commits, even if unchanged
f,force-rebase! cherry-pick all commits, even if unchanged
m,merge! use merging strategies to rebase
i,interactive! let the user edit the list of commits to rebase
x,exec=! add exec lines after each commit of the editable list
k,keep-empty preserve empty commits during rebase
allow-empty-message allow rebasing commits with empty messages
stat! display a diffstat of what changed upstream
n,no-stat! do not show diffstat of what changed upstream
verify allow pre-rebase hook to run
rerere-autoupdate allow rerere to update index with resolved conflicts
root! rebase all reachable commits up to the root(s)
autosquash move commits that begin with squash!/fixup! under -i
signoff add a Signed-off-by: line to each commit
committer-date-is-author-date! passed to 'git am'
ignore-date! passed to 'git am'
whitespace=! passed to 'git apply'
ignore-whitespace! passed to 'git apply'
C=! passed to 'git apply'
S,gpg-sign? GPG-sign commits
Actions:
continue! continue
abort! abort and check out the original branch
skip! skip current patch and continue
edit-todo! edit the todo list during an interactive rebase
quit! abort but keep HEAD where it is
show-current-patch! show the patch file being applied or merged
"
. git-sh-setup
set_reflog_action rebase
require_work_tree_exists
cd_to_toplevel
LF='
'
ok_to_skip_pre_rebase=
squash_onto=
unset onto
unset restrict_revision
cmd=
strategy=
strategy_opts=
do_merge=
merge_dir="$GIT_DIR"/rebase-merge
apply_dir="$GIT_DIR"/rebase-apply
verbose=
diffstat=
test "$(git config --bool rebase.stat)" = true && diffstat=t
autostash="$(git config --bool rebase.autostash || echo false)"
fork_point=auto
git_am_opt=
git_format_patch_opt=
rebase_root=
force_rebase=
allow_rerere_autoupdate=
# Non-empty if a rebase was in progress when 'git rebase' was invoked
in_progress=
# One of {am, merge, interactive}
type=
# One of {"$GIT_DIR"/rebase-apply, "$GIT_DIR"/rebase-merge}
state_dir=
# One of {'', continue, skip, abort}, as parsed from command line
action=
rebase_merges=
rebase_cousins=
preserve_merges=
autosquash=
keep_empty=
allow_empty_message=--allow-empty-message
signoff=
test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
case "$(git config --bool commit.gpgsign)" in
true) gpg_sign_opt=-S ;;
*) gpg_sign_opt= ;;
esac
. git-rebase--common
read_basic_state () {
test -f "$state_dir/head-name" &&
test -f "$state_dir/onto" &&
head_name=$(cat "$state_dir"/head-name) &&
onto=$(cat "$state_dir"/onto) &&
# We always write to orig-head, but interactive rebase used to write to
# head. Fall back to reading from head to cover for the case that the
# user upgraded git with an ongoing interactive rebase.
if test -f "$state_dir"/orig-head
then
orig_head=$(cat "$state_dir"/orig-head)
else
orig_head=$(cat "$state_dir"/head)
fi &&
GIT_QUIET=$(cat "$state_dir"/quiet) &&
test -f "$state_dir"/verbose && verbose=t
test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
test -f "$state_dir"/strategy_opts &&
strategy_opts="$(cat "$state_dir"/strategy_opts)"
test -f "$state_dir"/allow_rerere_autoupdate &&
allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
test -f "$state_dir"/gpg_sign_opt &&
gpg_sign_opt="$(cat "$state_dir"/gpg_sign_opt)"
test -f "$state_dir"/signoff && {
signoff="$(cat "$state_dir"/signoff)"
force_rebase=t
}
}
finish_rebase () {
rm -f "$(git rev-parse --git-path REBASE_HEAD)"
apply_autostash &&
{ git gc --auto || true; } &&
rm -rf "$state_dir"
}
run_interactive () {
GIT_CHERRY_PICK_HELP="$resolvemsg"
export GIT_CHERRY_PICK_HELP
test -n "$keep_empty" && keep_empty="--keep-empty"
test -n "$rebase_merges" && rebase_merges="--rebase-merges"
test -n "$rebase_cousins" && rebase_cousins="--rebase-cousins"
test -n "$autosquash" && autosquash="--autosquash"
test -n "$verbose" && verbose="--verbose"
test -n "$force_rebase" && force_rebase="--no-ff"
test -n "$restrict_revision" && \
restrict_revision="--restrict-revision=^$restrict_revision"
test -n "$upstream" && upstream="--upstream=$upstream"
test -n "$onto" && onto="--onto=$onto"
test -n "$squash_onto" && squash_onto="--squash-onto=$squash_onto"
test -n "$onto_name" && onto_name="--onto-name=$onto_name"
test -n "$head_name" && head_name="--head-name=$head_name"
test -n "$strategy" && strategy="--strategy=$strategy"
test -n "$strategy_opts" && strategy_opts="--strategy-opts=$strategy_opts"
test -n "$switch_to" && switch_to="--switch-to=$switch_to"
test -n "$cmd" && cmd="--cmd=$cmd"
test -n "$action" && action="--$action"
exec git rebase--interactive "$action" "$keep_empty" "$rebase_merges" "$rebase_cousins" \
"$upstream" "$onto" "$squash_onto" "$restrict_revision" \
"$allow_empty_message" "$autosquash" "$verbose" \
"$force_rebase" "$onto_name" "$head_name" "$strategy" \
"$strategy_opts" "$cmd" "$switch_to" \
"$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff"
}
run_specific_rebase () {
if [ "$interactive_rebase" = implied ]; then
GIT_EDITOR=:
export GIT_EDITOR
autosquash=
fi
if test -n "$interactive_rebase" -a -z "$preserve_merges"
then
run_interactive
else
. git-rebase--$type
if test -z "$preserve_merges"
then
git_rebase__$type
else
git_rebase__preserve_merges
fi
fi
ret=$?
if test $ret -eq 0
then
finish_rebase
elif test $ret -eq 2 # special exit status for rebase -p
then
apply_autostash &&
rm -rf "$state_dir" &&
die "Nothing to do"
fi
exit $ret
}
run_pre_rebase_hook () {
if test -z "$ok_to_skip_pre_rebase" &&
test -x "$(git rev-parse --git-path hooks/pre-rebase)"
then
"$(git rev-parse --git-path hooks/pre-rebase)" ${1+"$@"} ||
die "$(gettext "The pre-rebase hook refused to rebase.")"
fi
}
test -f "$apply_dir"/applying &&
die "$(gettext "It looks like 'git am' is in progress. Cannot rebase.")"
if test -d "$apply_dir"
then
type=am
state_dir="$apply_dir"
elif test -d "$merge_dir"
then
if test -d "$merge_dir"/rewritten
then
type=preserve-merges
interactive_rebase=explicit
preserve_merges=t
elif test -f "$merge_dir"/interactive
then
type=interactive
interactive_rebase=explicit
else
type=merge
fi
state_dir="$merge_dir"
fi
test -n "$type" && in_progress=t
total_argc=$#
while test $# != 0
do
case "$1" in
--no-verify)
ok_to_skip_pre_rebase=yes
;;
--verify)
ok_to_skip_pre_rebase=
;;
--continue|--skip|--abort|--quit|--edit-todo|--show-current-patch)
test $total_argc -eq 2 || usage
action=${1##--}
;;
--onto=*)
onto="${1#--onto=}"
;;
--exec=*)
cmd="${cmd}exec ${1#--exec=}${LF}"
test -z "$interactive_rebase" && interactive_rebase=implied
;;
--interactive)
interactive_rebase=explicit
;;
--keep-empty)
keep_empty=yes
;;
--allow-empty-message)
allow_empty_message=--allow-empty-message
;;
--no-keep-empty)
keep_empty=
;;
--rebase-merges)
rebase_merges=t
test -z "$interactive_rebase" && interactive_rebase=implied
;;
--rebase-merges=*)
rebase_merges=t
case "${1#*=}" in
rebase-cousins) rebase_cousins=t;;
no-rebase-cousins) rebase_cousins=;;
*) die "Unknown mode: $1";;
esac
test -z "$interactive_rebase" && interactive_rebase=implied
;;
--preserve-merges)
preserve_merges=t
test -z "$interactive_rebase" && interactive_rebase=implied
;;
--autosquash)
autosquash=t
;;
--no-autosquash)
autosquash=
;;
--fork-point)
fork_point=t
;;
--no-fork-point)
fork_point=
;;
--merge)
do_merge=t
;;
--strategy-option=*)
strategy_opts="$strategy_opts $(git rev-parse --sq-quote "--${1#--strategy-option=}" | sed -e s/^.//)"
do_merge=t
test -z "$strategy" && strategy=recursive
;;
--strategy=*)
strategy="${1#--strategy=}"
do_merge=t
;;
--no-stat)
diffstat=
;;
--stat)
diffstat=t
;;
--autostash)
autostash=true
;;
--no-autostash)
autostash=false
;;
--verbose)
verbose=t
diffstat=t
GIT_QUIET=
;;
--quiet)
GIT_QUIET=t
git_am_opt="$git_am_opt -q"
verbose=
diffstat=
;;
--whitespace=*)
git_am_opt="$git_am_opt --whitespace=${1#--whitespace=}"
case "${1#--whitespace=}" in
fix|strip)
force_rebase=t
;;
warn|nowarn|error|error-all)
;; # okay, known whitespace option
*)
die "fatal: Invalid whitespace option: '${1#*=}'"
;;
esac
;;
--ignore-whitespace)
git_am_opt="$git_am_opt $1"
;;
--signoff)
signoff=--signoff
;;
--no-signoff)
signoff=
;;
--committer-date-is-author-date|--ignore-date)
git_am_opt="$git_am_opt $1"
force_rebase=t
;;
-C*[!0-9]*)
die "fatal: switch \`C' expects a numerical value"
;;
-C*)
git_am_opt="$git_am_opt $1"
;;
--root)
rebase_root=t
;;
--force-rebase|--no-ff)
force_rebase=t
;;
--rerere-autoupdate|--no-rerere-autoupdate)
allow_rerere_autoupdate="$1"
;;
--gpg-sign)
gpg_sign_opt=-S
;;
--gpg-sign=*)
gpg_sign_opt="-S${1#--gpg-sign=}"
;;
--)
shift
break
;;
*)
usage
;;
esac
shift
done
test $# -gt 2 && usage
if test -n "$action"
then
test -z "$in_progress" && die "$(gettext "No rebase in progress?")"
# Only interactive rebase uses detailed reflog messages
if test -n "$interactive_rebase" && test "$GIT_REFLOG_ACTION" = rebase
then
GIT_REFLOG_ACTION="rebase -i ($action)"
export GIT_REFLOG_ACTION
fi
fi
if test "$action" = "edit-todo" && test -z "$interactive_rebase"
then
die "$(gettext "The --edit-todo action can only be used during interactive rebase.")"
fi
case "$action" in
continue)
# Sanity check
git rev-parse --verify HEAD >/dev/null ||
die "$(gettext "Cannot read HEAD")"
git update-index --ignore-submodules --refresh &&
git diff-files --quiet --ignore-submodules || {
echo "$(gettext "You must edit all merge conflicts and then
mark them as resolved using git add")"
exit 1
}
read_basic_state
run_specific_rebase
;;
skip)
output git reset --hard HEAD || exit $?
read_basic_state
run_specific_rebase
;;
abort)
git rerere clear
read_basic_state
case "$head_name" in
refs/*)
git symbolic-ref -m "rebase: aborting" HEAD $head_name ||
die "$(eval_gettext "Could not move back to \$head_name")"
;;
esac
output git reset --hard $orig_head
finish_rebase
exit
;;
quit)
exec rm -rf "$state_dir"
;;
edit-todo)
run_specific_rebase
;;
show-current-patch)
run_specific_rebase
die "BUG: run_specific_rebase is not supposed to return here"
;;
esac
# Make sure no rebase is in progress
if test -n "$in_progress"
then
state_dir_base=${state_dir##*/}
cmd_live_rebase="git rebase (--continue | --abort | --skip)"
cmd_clear_stale_rebase="rm -fr \"$state_dir\""
die "
$(eval_gettext 'It seems that there is already a $state_dir_base directory, and
I wonder if you are in the middle of another rebase. If that is the
case, please try
$cmd_live_rebase
If that is not the case, please
$cmd_clear_stale_rebase
and run me again. I am stopping in case you still have something
valuable there.')"
fi
if test -n "$rebase_root" && test -z "$onto"
then
test -z "$interactive_rebase" && interactive_rebase=implied
fi
if test -n "$keep_empty"
then
test -z "$interactive_rebase" && interactive_rebase=implied
fi
if test -n "$interactive_rebase"
then
if test -z "$preserve_merges"
then
type=interactive
else
type=preserve-merges
fi
state_dir="$merge_dir"
elif test -n "$do_merge"
then
type=merge
state_dir="$merge_dir"
else
type=am
state_dir="$apply_dir"
fi
if test -t 2 && test -z "$GIT_QUIET"
then
git_format_patch_opt="$git_format_patch_opt --progress"
fi
if test -n "$git_am_opt"; then
incompatible_opts=$(echo " $git_am_opt " | \
sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
if test -n "$interactive_rebase"
then
if test -n "$incompatible_opts"
then
die "$(gettext "error: cannot combine interactive options (--interactive, --exec, --rebase-merges, --preserve-merges, --keep-empty, --root + --onto) with am options ($incompatible_opts)")"
fi
fi
if test -n "$do_merge"; then
if test -n "$incompatible_opts"
then
die "$(gettext "error: cannot combine merge options (--merge, --strategy, --strategy-option) with am options ($incompatible_opts)")"
fi
fi
fi
if test -n "$signoff"
then
test -n "$preserve_merges" &&
die "$(gettext "error: cannot combine '--signoff' with '--preserve-merges'")"
git_am_opt="$git_am_opt $signoff"
force_rebase=t
fi
if test -n "$preserve_merges"
then
# Note: incompatibility with --signoff handled in signoff block above
# Note: incompatibility with --interactive is just a strong warning;
# git-rebase.txt caveats with "unless you know what you are doing"
test -n "$rebase_merges" &&
die "$(gettext "error: cannot combine '--preserve-merges' with '--rebase-merges'")"
fi
if test -n "$rebase_merges"
then
test -n "$strategy_opts" &&
die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy-option'")"
test -n "$strategy" &&
die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy'")"
fi
if test -z "$rebase_root"
then
case "$#" in
0)
if ! upstream_name=$(git rev-parse --symbolic-full-name \
--verify -q @{upstream} 2>/dev/null)
then
. git-parse-remote
error_on_missing_default_upstream "rebase" "rebase" \
"against" "git rebase $(gettext '<branch>')"
fi
test "$fork_point" = auto && fork_point=t
;;
*) upstream_name="$1"
if test "$upstream_name" = "-"
then
upstream_name="@{-1}"
fi
shift
;;
esac
upstream=$(peel_committish "${upstream_name}") ||
die "$(eval_gettext "invalid upstream '\$upstream_name'")"
upstream_arg="$upstream_name"
else
if test -z "$onto"
then
empty_tree=$(git hash-object -t tree /dev/null)
onto=$(git commit-tree $empty_tree </dev/null)
squash_onto="$onto"
fi
unset upstream_name
unset upstream
test $# -gt 1 && usage
upstream_arg=--root
fi
# Make sure the branch to rebase onto is valid.
onto_name=${onto-"$upstream_name"}
case "$onto_name" in
*...*)
if left=${onto_name%...*} right=${onto_name#*...} &&
onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
then
case "$onto" in
?*"$LF"?*)
die "$(eval_gettext "\$onto_name: there are more than one merge bases")"
;;
'')
die "$(eval_gettext "\$onto_name: there is no merge base")"
;;
esac
else
die "$(eval_gettext "\$onto_name: there is no merge base")"
fi
;;
*)
onto=$(peel_committish "$onto_name") ||
die "$(eval_gettext "Does not point to a valid commit: \$onto_name")"
;;
esac
# If the branch to rebase is given, that is the branch we will rebase
# $branch_name -- branch/commit being rebased, or HEAD (already detached)
# $orig_head -- commit object name of tip of the branch before rebasing
# $head_name -- refs/heads/<that-branch> or "detached HEAD"
switch_to=
case "$#" in
1)
# Is it "rebase other $branchname" or "rebase other $commit"?
branch_name="$1"
switch_to="$1"
# Is it a local branch?
if git show-ref --verify --quiet -- "refs/heads/$branch_name" &&
orig_head=$(git rev-parse -q --verify "refs/heads/$branch_name")
then
head_name="refs/heads/$branch_name"
# If not is it a valid ref (branch or commit)?
elif orig_head=$(git rev-parse -q --verify "$branch_name")
then
head_name="detached HEAD"
else
die "$(eval_gettext "fatal: no such branch/commit '\$branch_name'")"
fi
;;
0)
# Do not need to switch branches, we are already on it.
if branch_name=$(git symbolic-ref -q HEAD)
then
head_name=$branch_name
branch_name=$(expr "z$branch_name" : 'zrefs/heads/\(.*\)')
else
head_name="detached HEAD"
branch_name=HEAD
fi
orig_head=$(git rev-parse --verify HEAD) || exit
;;
*)
die "BUG: unexpected number of arguments left to parse"
;;
esac
if test "$fork_point" = t
then
new_upstream=$(git merge-base --fork-point "$upstream_name" \
"${switch_to:-HEAD}")
if test -n "$new_upstream"
then
restrict_revision=$new_upstream
fi
fi
if test "$autostash" = true && ! (require_clean_work_tree) 2>/dev/null
then
stash_sha1=$(git stash create "autostash") ||
die "$(gettext 'Cannot autostash')"
mkdir -p "$state_dir" &&
echo $stash_sha1 >"$state_dir/autostash" &&
stash_abbrev=$(git rev-parse --short $stash_sha1) &&
echo "$(eval_gettext 'Created autostash: $stash_abbrev')" &&
git reset --hard
fi
require_clean_work_tree "rebase" "$(gettext "Please commit or stash them.")"
# Now we are rebasing commits $upstream..$orig_head (or with --root,
# everything leading up to $orig_head) on top of $onto
# Check if we are already based on $onto with linear history,
# but this should be done only when upstream and onto are the same
# and if this is not an interactive rebase.
mb=$(git merge-base "$onto" "$orig_head")
if test -z "$interactive_rebase" && test "$upstream" = "$onto" &&
test "$mb" = "$onto" && test -z "$restrict_revision" &&
# linear history?
! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
then
if test -z "$force_rebase"
then
# Lazily switch to the target branch if needed...
test -z "$switch_to" ||
GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $switch_to" \
git checkout -q "$switch_to" --
if test "$branch_name" = "HEAD" &&
! git symbolic-ref -q HEAD
then
say "$(eval_gettext "HEAD is up to date.")"
else
say "$(eval_gettext "Current branch \$branch_name is up to date.")"
fi
finish_rebase
exit 0
else
if test "$branch_name" = "HEAD" &&
! git symbolic-ref -q HEAD
then
say "$(eval_gettext "HEAD is up to date, rebase forced.")"
else
say "$(eval_gettext "Current branch \$branch_name is up to date, rebase forced.")"
fi
fi
fi
# If a hook exists, give it a chance to interrupt
run_pre_rebase_hook "$upstream_arg" "$@"
if test -n "$diffstat"
then
if test -n "$verbose"
then
if test -z "$mb"
then
echo "$(eval_gettext "Changes to \$onto:")"
else
echo "$(eval_gettext "Changes from \$mb to \$onto:")"
fi
fi
mb_tree="${mb:-$(git hash-object -t tree /dev/null)}"
# We want color (if set), but no pager
GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
fi
test -n "$interactive_rebase" && run_specific_rebase
# Detach HEAD and reset the tree
say "$(gettext "First, rewinding head to replay your work on top of it...")"
GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
git checkout -q "$onto^0" || die "could not detach HEAD"
git update-ref ORIG_HEAD $orig_head
# If the $onto is a proper descendant of the tip of the branch, then
# we just fast-forwarded.
if test "$mb" = "$orig_head"
then
say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
move_to_original_branch
finish_rebase
exit 0
fi
if test -n "$rebase_root"
then
revisions="$onto..$orig_head"
else
revisions="${restrict_revision-$upstream}..$orig_head"
fi
run_specific_rebase