diff options
| -rw-r--r-- | Documentation/git-rebase.txt | 23 | ||||
| -rwxr-xr-x | git-rebase--interactive.sh | 110 | ||||
| -rwxr-xr-x | t/t3404-rebase-interactive.sh | 22 |
3 files changed, 151 insertions, 4 deletions
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt index 2e3363a61..96907d486 100644 --- a/Documentation/git-rebase.txt +++ b/Documentation/git-rebase.txt @@ -9,7 +9,7 @@ SYNOPSIS -------- [verse] 'git-rebase' [-i | --interactive] [-v | --verbose] [--merge] [-C<n>] - [--onto <newbase>] <upstream> [<branch>] + [-p | --preserve-merges] [--onto <newbase>] <upstream> [<branch>] 'git-rebase' --continue | --skip | --abort DESCRIPTION @@ -213,6 +213,10 @@ OPTIONS Make a list of the commits which are about to be rebased. Let the user edit that list before rebasing. +-p, \--preserve-merges:: + Instead of ignoring merges, try to recreate them. This option + only works in interactive mode. + include::merge-strategies.txt[] NOTES @@ -304,6 +308,23 @@ $ git rebase -i HEAD~5 And move the first patch to the end of the list. +You might want to preserve merges, if you have a history like this: + +------------------ + X + \ + A---M---B + / +---o---O---P---Q +------------------ + +Suppose you want to rebase the side branch starting at "A" to "Q". Make +sure that the current HEAD is "B", and call + +----------------------------- +$ git rebase -i -p --onto Q O +----------------------------- + Authors ------ Written by Junio C Hamano <junkio@cox.net> and diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh index f0f245797..0c2a9697c 100755 --- a/git-rebase--interactive.sh +++ b/git-rebase--interactive.sh @@ -10,7 +10,8 @@ # The original idea comes from Eric W. Biederman, in # http://article.gmane.org/gmane.comp.version-control.git/22407 -USAGE='(--continue | --abort | --skip | [--onto <branch>] <upstream> [<branch>])' +USAGE='(--continue | --abort | --skip | [--preserve-merges] [--verbose] + [--onto <branch>] <upstream> [<branch>])' . git-sh-setup require_work_tree @@ -18,6 +19,8 @@ require_work_tree DOTEST="$GIT_DIR/.dotest-merge" TODO="$DOTEST"/todo DONE="$DOTEST"/done +REWRITTEN="$DOTEST"/rewritten +PRESERVE_MERGES= STRATEGY= VERBOSE= @@ -68,6 +71,8 @@ die_abort () { pick_one () { case "$1" in -n) sha1=$2 ;; *) sha1=$1 ;; esac git rev-parse --verify $sha1 || die "Invalid commit name: $sha1" + test -d "$REWRITTEN" && + pick_one_preserving_merges "$@" && return parent_sha1=$(git rev-parse --verify $sha1^ 2>/dev/null) current_sha1=$(git rev-parse --verify HEAD) if [ $current_sha1 = $parent_sha1 ]; then @@ -79,6 +84,75 @@ pick_one () { fi } +pick_one_preserving_merges () { + case "$1" in -n) sha1=$2 ;; *) sha1=$1 ;; esac + sha1=$(git rev-parse $sha1) + + if [ -f "$DOTEST"/current-commit ] + then + current_commit=$(cat "$DOTEST"/current-commit) && + git rev-parse HEAD > "$REWRITTEN"/$current_commit && + rm "$DOTEST"/current-commit || + die "Cannot write current commit's replacement sha1" + fi + + # rewrite parents; if none were rewritten, we can fast-forward. + fast_forward=t + preserve=t + new_parents= + for p in $(git rev-list --parents -1 $sha1 | cut -d\ -f2-) + do + if [ -f "$REWRITTEN"/$p ] + then + preserve=f + new_p=$(cat "$REWRITTEN"/$p) + test $p != $new_p && fast_forward=f + case "$new_parents" in + *$new_p*) + ;; # do nothing; that parent is already there + *) + new_parents="$new_parents $new_p" + esac + fi + done + case $fast_forward in + t) + echo "Fast forward to $sha1" + test $preserve=f && echo $sha1 > "$REWRITTEN"/$sha1 + ;; + f) + test "a$1" = a-n && die "Refusing to squash a merge: $sha1" + + first_parent=$(expr "$new_parents" : " \([^ ]*\)") + # detach HEAD to current parent + git checkout $first_parent 2> /dev/null || + die "Cannot move HEAD to $first_parent" + + echo $sha1 > "$DOTEST"/current-commit + case "$new_parents" in + \ *\ *) + # redo merge + author_script=$(get_author_ident_from_commit $sha1) + eval "$author_script" + msg="$(git cat-file commit $sha1 | \ + sed -e '1,/^$/d' -e "s/[\"\\]/\\\\&/g")" + # NEEDSWORK: give rerere a chance + if ! git merge $STRATEGY -m "$msg" $new_parents + then + echo "$msg" > "$GIT_DIR"/MERGE_MSG + warn Error redoing merge $sha1 + warn + warn After fixup, please use + die "$author_script git commit" + fi + ;; + *) + git cherry-pick $STRATEGY "$@" || + die_with_patch $sha1 "Could not pick $sha1" + esac + esac +} + do_next () { read command sha1 rest < "$TODO" case "$command" in @@ -155,7 +229,15 @@ do_next () { HEADNAME=$(cat "$DOTEST"/head-name) && OLDHEAD=$(cat "$DOTEST"/head) && SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) && - NEWHEAD=$(git rev-parse HEAD) && + if [ -d "$REWRITTEN" ] + then + test -f "$DOTEST"/current-commit && + current_commit=$(cat "$DOTEST"/current-commit) && + git rev-parse HEAD > "$REWRITTEN"/$current_commit + NEWHEAD=$(cat "$REWRITTEN"/$OLDHEAD) + else + NEWHEAD=$(git rev-parse HEAD) + fi && message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO)" && git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD && git symbolic-ref HEAD $HEADNAME && @@ -226,6 +308,9 @@ do -v|--verbose) VERBOSE=t ;; + -p|--preserve-merges) + PRESERVE_MERGES=t + ;; -i|--interactive) # yeah, we know ;; @@ -274,6 +359,25 @@ do echo $UPSTREAM > "$DOTEST"/upstream echo $ONTO > "$DOTEST"/onto test t = "$VERBOSE" && : > "$DOTEST"/verbose + if [ t = "$PRESERVE_MERGES" ] + then + # $REWRITTEN contains files for each commit that is + # reachable by at least one merge base of $HEAD and + # $UPSTREAM. They are not necessarily rewritten, but + # their children might be. + # This ensures that commits on merged, but otherwise + # unrelated side branches are left alone. (Think "X" + # in the man page's example.) + mkdir "$REWRITTEN" && + for c in $(git merge-base --all $HEAD $UPSTREAM) + do + echo $ONTO > "$REWRITTEN"/$c || + die "Could not init rewritten commits" + done + MERGES_OPTION= + else + MERGES_OPTION=--no-merges + fi SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM) SHORTHEAD=$(git rev-parse --short $HEAD) @@ -286,7 +390,7 @@ do # edit = use commit, but stop for amending # squash = use commit, but meld into previous commit EOF - git rev-list --no-merges --pretty=oneline --abbrev-commit \ + git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \ --abbrev=7 --reverse $UPSTREAM..$HEAD | \ sed "s/^/pick /" >> "$TODO" diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh index 9f12bb932..883cf2959 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -166,4 +166,26 @@ test_expect_success 'retain authorship when squashing' ' git show HEAD | grep "^Author: Nitfol" ' +test_expect_success 'preserve merges with -p' ' + git checkout -b to-be-preserved master^ && + : > unrelated-file && + git add unrelated-file && + test_tick && + git commit -m "unrelated" && + git checkout -b to-be-rebased master && + echo B > file1 && + test_tick && + git commit -m J file1 && + test_tick && + git merge to-be-preserved && + echo C > file1 && + test_tick && + git commit -m K file1 && + git rebase -i -p --onto branch1 master && + test $(git rev-parse HEAD^^2) = $(git rev-parse to-be-preserved) && + test $(git rev-parse HEAD~3) = $(git rev-parse branch1) && + test $(git show HEAD:file1) = C && + test $(git show HEAD~2:file1) = B +' + test_done |