db10dd7b296db75906760adb7417cf6681d3cea0
   1#!/bin/sh
   2#
   3# Copyright (c) 2006 Johannes E. Schindelin
   4
   5# SHORT DESCRIPTION
   6#
   7# This script makes it easy to fix up commits in the middle of a series,
   8# and rearrange commits.
   9#
  10# The original idea comes from Eric W. Biederman, in
  11# http://article.gmane.org/gmane.comp.version-control.git/22407
  12
  13OPTIONS_KEEPDASHDASH=
  14OPTIONS_SPEC="\
  15git-rebase [-i] [options] [--] <upstream> [<branch>]
  16git-rebase [-i] (--continue | --abort | --skip)
  17--
  18 Available options are
  19v,verbose          display a diffstat of what changed upstream
  20onto=              rebase onto given branch instead of upstream
  21p,preserve-merges  try to recreate merges instead of ignoring them
  22s,strategy=        use the given merge strategy
  23m,merge            always used (no-op)
  24i,interactive      always used (no-op)
  25 Actions:
  26continue           continue rebasing process
  27abort              abort rebasing process and restore original branch
  28skip               skip current patch and continue rebasing process
  29no-verify          override pre-rebase hook from stopping the operation
  30root               rebase all reachable commmits up to the root(s)
  31"
  32
  33. git-sh-setup
  34require_work_tree
  35
  36DOTEST="$GIT_DIR/rebase-merge"
  37TODO="$DOTEST"/git-rebase-todo
  38DONE="$DOTEST"/done
  39MSG="$DOTEST"/message
  40SQUASH_MSG="$DOTEST"/message-squash
  41REWRITTEN="$DOTEST"/rewritten
  42DROPPED="$DOTEST"/dropped
  43PRESERVE_MERGES=
  44STRATEGY=
  45ONTO=
  46VERBOSE=
  47OK_TO_SKIP_PRE_REBASE=
  48REBASE_ROOT=
  49
  50GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
  51mark the corrected paths with 'git add <paths>', and
  52run 'git rebase --continue'"
  53export GIT_CHERRY_PICK_HELP
  54
  55warn () {
  56        echo "$*" >&2
  57}
  58
  59output () {
  60        case "$VERBOSE" in
  61        '')
  62                output=$("$@" 2>&1 )
  63                status=$?
  64                test $status != 0 && printf "%s\n" "$output"
  65                return $status
  66                ;;
  67        *)
  68                "$@"
  69                ;;
  70        esac
  71}
  72
  73run_pre_rebase_hook () {
  74        if test -z "$OK_TO_SKIP_PRE_REBASE" &&
  75           test -x "$GIT_DIR/hooks/pre-rebase"
  76        then
  77                "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
  78                        echo >&2 "The pre-rebase hook refused to rebase."
  79                        exit 1
  80                }
  81        fi
  82}
  83
  84require_clean_work_tree () {
  85        # test if working tree is dirty
  86        git rev-parse --verify HEAD > /dev/null &&
  87        git update-index --ignore-submodules --refresh &&
  88        git diff-files --quiet --ignore-submodules &&
  89        git diff-index --cached --quiet HEAD --ignore-submodules -- ||
  90        die "Working tree is dirty"
  91}
  92
  93ORIG_REFLOG_ACTION="$GIT_REFLOG_ACTION"
  94
  95comment_for_reflog () {
  96        case "$ORIG_REFLOG_ACTION" in
  97        ''|rebase*)
  98                GIT_REFLOG_ACTION="rebase -i ($1)"
  99                export GIT_REFLOG_ACTION
 100                ;;
 101        esac
 102}
 103
 104last_count=
 105mark_action_done () {
 106        sed -e 1q < "$TODO" >> "$DONE"
 107        sed -e 1d < "$TODO" >> "$TODO".new
 108        mv -f "$TODO".new "$TODO"
 109        count=$(sane_grep -c '^[^#]' < "$DONE")
 110        total=$(($count+$(sane_grep -c '^[^#]' < "$TODO")))
 111        if test "$last_count" != "$count"
 112        then
 113                last_count=$count
 114                printf "Rebasing (%d/%d)\r" $count $total
 115                test -z "$VERBOSE" || echo
 116        fi
 117}
 118
 119make_patch () {
 120        sha1_and_parents="$(git rev-list --parents -1 "$1")"
 121        case "$sha1_and_parents" in
 122        ?*' '?*' '?*)
 123                git diff --cc $sha1_and_parents
 124                ;;
 125        ?*' '?*)
 126                git diff-tree -p "$1^!"
 127                ;;
 128        *)
 129                echo "Root commit"
 130                ;;
 131        esac > "$DOTEST"/patch
 132        test -f "$DOTEST"/message ||
 133                git cat-file commit "$1" | sed "1,/^$/d" > "$DOTEST"/message
 134        test -f "$DOTEST"/author-script ||
 135                get_author_ident_from_commit "$1" > "$DOTEST"/author-script
 136}
 137
 138die_with_patch () {
 139        make_patch "$1"
 140        git rerere
 141        die "$2"
 142}
 143
 144die_abort () {
 145        rm -rf "$DOTEST"
 146        die "$1"
 147}
 148
 149has_action () {
 150        sane_grep '^[^#]' "$1" >/dev/null
 151}
 152
 153pick_one () {
 154        no_ff=
 155        case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
 156        output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
 157        test -d "$REWRITTEN" &&
 158                pick_one_preserving_merges "$@" && return
 159        if test ! -z "$REBASE_ROOT"
 160        then
 161                output git cherry-pick "$@"
 162                return
 163        fi
 164        parent_sha1=$(git rev-parse --verify $sha1^) ||
 165                die "Could not get the parent of $sha1"
 166        current_sha1=$(git rev-parse --verify HEAD)
 167        if test -z "$no_ff" -a "$current_sha1" = "$parent_sha1"
 168        then
 169                output git reset --hard $sha1
 170                test "a$1" = a-n && output git reset --soft $current_sha1
 171                sha1=$(git rev-parse --short $sha1)
 172                output warn Fast-forward to $sha1
 173        else
 174                output git cherry-pick "$@"
 175        fi
 176}
 177
 178pick_one_preserving_merges () {
 179        fast_forward=t
 180        case "$1" in
 181        -n)
 182                fast_forward=f
 183                sha1=$2
 184                ;;
 185        *)
 186                sha1=$1
 187                ;;
 188        esac
 189        sha1=$(git rev-parse $sha1)
 190
 191        if test -f "$DOTEST"/current-commit
 192        then
 193                if test "$fast_forward" = t
 194                then
 195                        cat "$DOTEST"/current-commit | while read current_commit
 196                        do
 197                                git rev-parse HEAD > "$REWRITTEN"/$current_commit
 198                        done
 199                        rm "$DOTEST"/current-commit ||
 200                        die "Cannot write current commit's replacement sha1"
 201                fi
 202        fi
 203
 204        echo $sha1 >> "$DOTEST"/current-commit
 205
 206        # rewrite parents; if none were rewritten, we can fast-forward.
 207        new_parents=
 208        pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
 209        if test "$pend" = " "
 210        then
 211                pend=" root"
 212        fi
 213        while [ "$pend" != "" ]
 214        do
 215                p=$(expr "$pend" : ' \([^ ]*\)')
 216                pend="${pend# $p}"
 217
 218                if test -f "$REWRITTEN"/$p
 219                then
 220                        new_p=$(cat "$REWRITTEN"/$p)
 221
 222                        # If the todo reordered commits, and our parent is marked for
 223                        # rewriting, but hasn't been gotten to yet, assume the user meant to
 224                        # drop it on top of the current HEAD
 225                        if test -z "$new_p"
 226                        then
 227                                new_p=$(git rev-parse HEAD)
 228                        fi
 229
 230                        test $p != $new_p && fast_forward=f
 231                        case "$new_parents" in
 232                        *$new_p*)
 233                                ;; # do nothing; that parent is already there
 234                        *)
 235                                new_parents="$new_parents $new_p"
 236                                ;;
 237                        esac
 238                else
 239                        if test -f "$DROPPED"/$p
 240                        then
 241                                fast_forward=f
 242                                replacement="$(cat "$DROPPED"/$p)"
 243                                test -z "$replacement" && replacement=root
 244                                pend=" $replacement$pend"
 245                        else
 246                                new_parents="$new_parents $p"
 247                        fi
 248                fi
 249        done
 250        case $fast_forward in
 251        t)
 252                output warn "Fast-forward to $sha1"
 253                output git reset --hard $sha1 ||
 254                        die "Cannot fast-forward to $sha1"
 255                ;;
 256        f)
 257                first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
 258
 259                if [ "$1" != "-n" ]
 260                then
 261                        # detach HEAD to current parent
 262                        output git checkout $first_parent 2> /dev/null ||
 263                                die "Cannot move HEAD to $first_parent"
 264                fi
 265
 266                case "$new_parents" in
 267                ' '*' '*)
 268                        test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 269
 270                        # redo merge
 271                        author_script=$(get_author_ident_from_commit $sha1)
 272                        eval "$author_script"
 273                        msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
 274                        # No point in merging the first parent, that's HEAD
 275                        new_parents=${new_parents# $first_parent}
 276                        if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 277                                GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 278                                GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
 279                                output git merge $STRATEGY -m "$msg" \
 280                                        $new_parents
 281                        then
 282                                printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
 283                                die_with_patch $sha1 "Error redoing merge $sha1"
 284                        fi
 285                        ;;
 286                *)
 287                        output git cherry-pick "$@" ||
 288                                die_with_patch $sha1 "Could not pick $sha1"
 289                        ;;
 290                esac
 291                ;;
 292        esac
 293}
 294
 295nth_string () {
 296        case "$1" in
 297        *1[0-9]|*[04-9]) echo "$1"th;;
 298        *1) echo "$1"st;;
 299        *2) echo "$1"nd;;
 300        *3) echo "$1"rd;;
 301        esac
 302}
 303
 304make_squash_message () {
 305        if test -f "$SQUASH_MSG"; then
 306                # We want to be careful about matching only the commit
 307                # message comment lines generated by this function.
 308                # "[snrt][tdh]" matches the nth_string endings.
 309                COUNT=$(($(sed -n "s/^# Th[^0-9]*\([1-9][0-9]*\)[snrt][tdh] commit message.*:/\1/p" \
 310                        < "$SQUASH_MSG" | sed -ne '$p')+1))
 311                echo "# This is a combination of $COUNT commits."
 312                sed -e 1d -e '2,/^./{
 313                        /^$/d
 314                }' <"$SQUASH_MSG"
 315        else
 316                COUNT=2
 317                echo "# This is a combination of two commits."
 318                echo "# The first commit's message is:"
 319                echo
 320                git cat-file commit HEAD | sed -e '1,/^$/d'
 321        fi
 322        case $1 in
 323        squash)
 324                echo
 325                echo "# This is the $(nth_string $COUNT) commit message:"
 326                echo
 327                git cat-file commit $2 | sed -e '1,/^$/d'
 328                ;;
 329        fixup)
 330                echo
 331                echo "# The $(nth_string $COUNT) commit message will be skipped:"
 332                echo
 333                # Comment the lines of the commit message out using
 334                # "#    " rather than "# " to make them less likely to
 335                # confuse the sed regexp above.
 336                git cat-file commit $2 | sed -e '1,/^$/d' -e 's/^/#     /'
 337                ;;
 338        esac
 339}
 340
 341peek_next_command () {
 342        sed -n -e "/^#/d" -e "/^$/d" -e "s/ .*//p" -e "q" < "$TODO"
 343}
 344
 345do_next () {
 346        rm -f "$DOTEST"/message "$DOTEST"/author-script \
 347                "$DOTEST"/amend || exit
 348        read command sha1 rest < "$TODO"
 349        case "$command" in
 350        '#'*|''|noop)
 351                mark_action_done
 352                ;;
 353        pick|p)
 354                comment_for_reflog pick
 355
 356                mark_action_done
 357                pick_one $sha1 ||
 358                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 359                ;;
 360        reword|r)
 361                comment_for_reflog reword
 362
 363                mark_action_done
 364                pick_one $sha1 ||
 365                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 366                git commit --amend
 367                ;;
 368        edit|e)
 369                comment_for_reflog edit
 370
 371                mark_action_done
 372                pick_one $sha1 ||
 373                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 374                make_patch $sha1
 375                git rev-parse --verify HEAD > "$DOTEST"/amend
 376                warn "Stopped at $sha1... $rest"
 377                warn "You can amend the commit now, with"
 378                warn
 379                warn "  git commit --amend"
 380                warn
 381                warn "Once you are satisfied with your changes, run"
 382                warn
 383                warn "  git rebase --continue"
 384                warn
 385                exit 0
 386                ;;
 387        squash|s|fixup|f)
 388                case "$command" in
 389                squash|s)
 390                        squash_style=squash
 391                        ;;
 392                fixup|f)
 393                        squash_style=fixup
 394                        ;;
 395                esac
 396                comment_for_reflog $squash_style
 397
 398                test -f "$DONE" && has_action "$DONE" ||
 399                        die "Cannot '$squash_style' without a previous commit"
 400
 401                mark_action_done
 402                make_squash_message $squash_style $sha1 > "$MSG"
 403                failed=f
 404                author_script=$(get_author_ident_from_commit HEAD)
 405                output git reset --soft HEAD^
 406                pick_one -n $sha1 || failed=t
 407                case "$(peek_next_command)" in
 408                squash|s|fixup|f)
 409                        USE_OUTPUT=output
 410                        MSG_OPT=-F
 411                        EDIT_OR_FILE="$MSG"
 412                        cp "$MSG" "$SQUASH_MSG"
 413                        ;;
 414                *)
 415                        USE_OUTPUT=
 416                        MSG_OPT=
 417                        EDIT_OR_FILE=-e
 418                        rm -f "$SQUASH_MSG" || exit
 419                        cp "$MSG" "$GIT_DIR"/SQUASH_MSG
 420                        rm -f "$GIT_DIR"/MERGE_MSG || exit
 421                        ;;
 422                esac
 423                echo "$author_script" > "$DOTEST"/author-script
 424                if test $failed = f
 425                then
 426                        # This is like --amend, but with a different message
 427                        eval "$author_script"
 428                        GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 429                        GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 430                        GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
 431                        $USE_OUTPUT git commit --no-verify \
 432                                $MSG_OPT "$EDIT_OR_FILE" || failed=t
 433                fi
 434                if test $failed = t
 435                then
 436                        cp "$MSG" "$GIT_DIR"/MERGE_MSG
 437                        warn
 438                        warn "Could not apply $sha1... $rest"
 439                        die_with_patch $sha1 ""
 440                fi
 441                ;;
 442        *)
 443                warn "Unknown command: $command $sha1 $rest"
 444                if git rev-parse --verify -q "$sha1" >/dev/null
 445                then
 446                        die_with_patch $sha1 "Please fix this in the file $TODO."
 447                else
 448                        die "Please fix this in the file $TODO."
 449                fi
 450                ;;
 451        esac
 452        test -s "$TODO" && return
 453
 454        comment_for_reflog finish &&
 455        HEADNAME=$(cat "$DOTEST"/head-name) &&
 456        OLDHEAD=$(cat "$DOTEST"/head) &&
 457        SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
 458        NEWHEAD=$(git rev-parse HEAD) &&
 459        case $HEADNAME in
 460        refs/*)
 461                message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO" &&
 462                git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD &&
 463                git symbolic-ref HEAD $HEADNAME
 464                ;;
 465        esac && {
 466                test ! -f "$DOTEST"/verbose ||
 467                        git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
 468        } &&
 469        rm -rf "$DOTEST" &&
 470        git gc --auto &&
 471        warn "Successfully rebased and updated $HEADNAME."
 472
 473        exit
 474}
 475
 476do_rest () {
 477        while :
 478        do
 479                do_next
 480        done
 481}
 482
 483# skip picking commits whose parents are unchanged
 484skip_unnecessary_picks () {
 485        fd=3
 486        while read command sha1 rest
 487        do
 488                # fd=3 means we skip the command
 489                case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
 490                3,pick,"$ONTO"*|3,p,"$ONTO"*)
 491                        # pick a commit whose parent is current $ONTO -> skip
 492                        ONTO=$sha1
 493                        ;;
 494                3,#*|3,,*)
 495                        # copy comments
 496                        ;;
 497                *)
 498                        fd=1
 499                        ;;
 500                esac
 501                echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
 502        done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
 503        mv -f "$TODO".new "$TODO" ||
 504        die "Could not skip unnecessary pick commands"
 505}
 506
 507# check if no other options are set
 508is_standalone () {
 509        test $# -eq 2 -a "$2" = '--' &&
 510        test -z "$ONTO" &&
 511        test -z "$PRESERVE_MERGES" &&
 512        test -z "$STRATEGY" &&
 513        test -z "$VERBOSE"
 514}
 515
 516get_saved_options () {
 517        test -d "$REWRITTEN" && PRESERVE_MERGES=t
 518        test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 519        test -f "$DOTEST"/verbose && VERBOSE=t
 520        test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
 521}
 522
 523while test $# != 0
 524do
 525        case "$1" in
 526        --no-verify)
 527                OK_TO_SKIP_PRE_REBASE=yes
 528                ;;
 529        --verify)
 530                ;;
 531        --continue)
 532                is_standalone "$@" || usage
 533                get_saved_options
 534                comment_for_reflog continue
 535
 536                test -d "$DOTEST" || die "No interactive rebase running"
 537
 538                # Sanity check
 539                git rev-parse --verify HEAD >/dev/null ||
 540                        die "Cannot read HEAD"
 541                git update-index --ignore-submodules --refresh &&
 542                        git diff-files --quiet --ignore-submodules ||
 543                        die "Working tree is dirty"
 544
 545                # do we have anything to commit?
 546                if git diff-index --cached --quiet --ignore-submodules HEAD --
 547                then
 548                        : Nothing to commit -- skip this
 549                else
 550                        . "$DOTEST"/author-script ||
 551                                die "Cannot find the author identity"
 552                        amend=
 553                        if test -f "$DOTEST"/amend
 554                        then
 555                                amend=$(git rev-parse --verify HEAD)
 556                                test "$amend" = $(cat "$DOTEST"/amend) ||
 557                                die "\
 558You have uncommitted changes in your working tree. Please, commit them
 559first and then run 'git rebase --continue' again."
 560                                git reset --soft HEAD^ ||
 561                                die "Cannot rewind the HEAD"
 562                        fi
 563                        export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE &&
 564                        git commit --no-verify -F "$DOTEST"/message -e || {
 565                                test -n "$amend" && git reset --soft $amend
 566                                die "Could not commit staged changes."
 567                        }
 568                fi
 569
 570                require_clean_work_tree
 571                do_rest
 572                ;;
 573        --abort)
 574                is_standalone "$@" || usage
 575                get_saved_options
 576                comment_for_reflog abort
 577
 578                git rerere clear
 579                test -d "$DOTEST" || die "No interactive rebase running"
 580
 581                HEADNAME=$(cat "$DOTEST"/head-name)
 582                HEAD=$(cat "$DOTEST"/head)
 583                case $HEADNAME in
 584                refs/*)
 585                        git symbolic-ref HEAD $HEADNAME
 586                        ;;
 587                esac &&
 588                output git reset --hard $HEAD &&
 589                rm -rf "$DOTEST"
 590                exit
 591                ;;
 592        --skip)
 593                is_standalone "$@" || usage
 594                get_saved_options
 595                comment_for_reflog skip
 596
 597                git rerere clear
 598                test -d "$DOTEST" || die "No interactive rebase running"
 599
 600                output git reset --hard && do_rest
 601                ;;
 602        -s)
 603                case "$#,$1" in
 604                *,*=*)
 605                        STRATEGY="-s "$(expr "z$1" : 'z-[^=]*=\(.*\)') ;;
 606                1,*)
 607                        usage ;;
 608                *)
 609                        STRATEGY="-s $2"
 610                        shift ;;
 611                esac
 612                ;;
 613        -m)
 614                # we use merge anyway
 615                ;;
 616        -v)
 617                VERBOSE=t
 618                ;;
 619        -p)
 620                PRESERVE_MERGES=t
 621                ;;
 622        -i)
 623                # yeah, we know
 624                ;;
 625        --root)
 626                REBASE_ROOT=t
 627                ;;
 628        --onto)
 629                shift
 630                ONTO=$(git rev-parse --verify "$1") ||
 631                        die "Does not point to a valid commit: $1"
 632                ;;
 633        --)
 634                shift
 635                test -z "$REBASE_ROOT" -a $# -ge 1 -a $# -le 2 ||
 636                test ! -z "$REBASE_ROOT" -a $# -le 1 || usage
 637                test -d "$DOTEST" &&
 638                        die "Interactive rebase already started"
 639
 640                git var GIT_COMMITTER_IDENT >/dev/null ||
 641                        die "You need to set your committer info first"
 642
 643                if test -z "$REBASE_ROOT"
 644                then
 645                        UPSTREAM_ARG="$1"
 646                        UPSTREAM=$(git rev-parse --verify "$1") || die "Invalid base"
 647                        test -z "$ONTO" && ONTO=$UPSTREAM
 648                        shift
 649                else
 650                        UPSTREAM=
 651                        UPSTREAM_ARG=--root
 652                        test -z "$ONTO" &&
 653                                die "You must specify --onto when using --root"
 654                fi
 655                run_pre_rebase_hook "$UPSTREAM_ARG" "$@"
 656
 657                comment_for_reflog start
 658
 659                require_clean_work_tree
 660
 661                if test ! -z "$1"
 662                then
 663                        output git show-ref --verify --quiet "refs/heads/$1" ||
 664                                die "Invalid branchname: $1"
 665                        output git checkout "$1" ||
 666                                die "Could not checkout $1"
 667                fi
 668
 669                HEAD=$(git rev-parse --verify HEAD) || die "No HEAD?"
 670                mkdir "$DOTEST" || die "Could not create temporary $DOTEST"
 671
 672                : > "$DOTEST"/interactive || die "Could not mark as interactive"
 673                git symbolic-ref HEAD > "$DOTEST"/head-name 2> /dev/null ||
 674                        echo "detached HEAD" > "$DOTEST"/head-name
 675
 676                echo $HEAD > "$DOTEST"/head
 677                case "$REBASE_ROOT" in
 678                '')
 679                        rm -f "$DOTEST"/rebase-root ;;
 680                *)
 681                        : >"$DOTEST"/rebase-root ;;
 682                esac
 683                echo $ONTO > "$DOTEST"/onto
 684                test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
 685                test t = "$VERBOSE" && : > "$DOTEST"/verbose
 686                if test t = "$PRESERVE_MERGES"
 687                then
 688                        # $REWRITTEN contains files for each commit that is
 689                        # reachable by at least one merge base of $HEAD and
 690                        # $UPSTREAM. They are not necessarily rewritten, but
 691                        # their children might be.
 692                        # This ensures that commits on merged, but otherwise
 693                        # unrelated side branches are left alone. (Think "X"
 694                        # in the man page's example.)
 695                        if test -z "$REBASE_ROOT"
 696                        then
 697                                mkdir "$REWRITTEN" &&
 698                                for c in $(git merge-base --all $HEAD $UPSTREAM)
 699                                do
 700                                        echo $ONTO > "$REWRITTEN"/$c ||
 701                                                die "Could not init rewritten commits"
 702                                done
 703                        else
 704                                mkdir "$REWRITTEN" &&
 705                                echo $ONTO > "$REWRITTEN"/root ||
 706                                        die "Could not init rewritten commits"
 707                        fi
 708                        # No cherry-pick because our first pass is to determine
 709                        # parents to rewrite and skipping dropped commits would
 710                        # prematurely end our probe
 711                        MERGES_OPTION=
 712                        first_after_upstream="$(git rev-list --reverse --first-parent $UPSTREAM..$HEAD | head -n 1)"
 713                else
 714                        MERGES_OPTION="--no-merges --cherry-pick"
 715                fi
 716
 717                SHORTHEAD=$(git rev-parse --short $HEAD)
 718                SHORTONTO=$(git rev-parse --short $ONTO)
 719                if test -z "$REBASE_ROOT"
 720                        # this is now equivalent to ! -z "$UPSTREAM"
 721                then
 722                        SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
 723                        REVISIONS=$UPSTREAM...$HEAD
 724                        SHORTREVISIONS=$SHORTUPSTREAM..$SHORTHEAD
 725                else
 726                        REVISIONS=$ONTO...$HEAD
 727                        SHORTREVISIONS=$SHORTHEAD
 728                fi
 729                git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 730                        --abbrev=7 --reverse --left-right --topo-order \
 731                        $REVISIONS | \
 732                        sed -n "s/^>//p" | while read shortsha1 rest
 733                do
 734                        if test t != "$PRESERVE_MERGES"
 735                        then
 736                                echo "pick $shortsha1 $rest" >> "$TODO"
 737                        else
 738                                sha1=$(git rev-parse $shortsha1)
 739                                if test -z "$REBASE_ROOT"
 740                                then
 741                                        preserve=t
 742                                        for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
 743                                        do
 744                                                if test -f "$REWRITTEN"/$p -a \( $p != $ONTO -o $sha1 = $first_after_upstream \)
 745                                                then
 746                                                        preserve=f
 747                                                fi
 748                                        done
 749                                else
 750                                        preserve=f
 751                                fi
 752                                if test f = "$preserve"
 753                                then
 754                                        touch "$REWRITTEN"/$sha1
 755                                        echo "pick $shortsha1 $rest" >> "$TODO"
 756                                fi
 757                        fi
 758                done
 759
 760                # Watch for commits that been dropped by --cherry-pick
 761                if test t = "$PRESERVE_MERGES"
 762                then
 763                        mkdir "$DROPPED"
 764                        # Save all non-cherry-picked changes
 765                        git rev-list $REVISIONS --left-right --cherry-pick | \
 766                                sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
 767                        # Now all commits and note which ones are missing in
 768                        # not-cherry-picks and hence being dropped
 769                        git rev-list $REVISIONS |
 770                        while read rev
 771                        do
 772                                if test -f "$REWRITTEN"/$rev -a "$(sane_grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
 773                                then
 774                                        # Use -f2 because if rev-list is telling us this commit is
 775                                        # not worthwhile, we don't want to track its multiple heads,
 776                                        # just the history of its first-parent for others that will
 777                                        # be rebasing on top of it
 778                                        git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
 779                                        short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
 780                                        sane_grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
 781                                        rm "$REWRITTEN"/$rev
 782                                fi
 783                        done
 784                fi
 785
 786                test -s "$TODO" || echo noop >> "$TODO"
 787                cat >> "$TODO" << EOF
 788
 789# Rebase $SHORTREVISIONS onto $SHORTONTO
 790#
 791# Commands:
 792#  p, pick = use commit
 793#  r, reword = use commit, but edit the commit message
 794#  e, edit = use commit, but stop for amending
 795#  s, squash = use commit, but meld into previous commit
 796#  f, fixup = like "squash", but discard this commit's log message
 797#
 798# If you remove a line here THAT COMMIT WILL BE LOST.
 799# However, if you remove everything, the rebase will be aborted.
 800#
 801EOF
 802
 803                has_action "$TODO" ||
 804                        die_abort "Nothing to do"
 805
 806                cp "$TODO" "$TODO".backup
 807                git_editor "$TODO" ||
 808                        die "Could not execute editor"
 809
 810                has_action "$TODO" ||
 811                        die_abort "Nothing to do"
 812
 813                test -d "$REWRITTEN" || skip_unnecessary_picks
 814
 815                git update-ref ORIG_HEAD $HEAD
 816                output git checkout $ONTO && do_rest
 817                ;;
 818        esac
 819        shift
 820done