git-rebase--interactive.shon commit rebase -i: Remove dead code (5043834)
   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 $sha1
 170                sha1=$(git rev-parse --short $sha1)
 171                output warn Fast-forward to $sha1
 172        else
 173                output git cherry-pick "$@"
 174        fi
 175}
 176
 177pick_one_preserving_merges () {
 178        fast_forward=t
 179        case "$1" in
 180        -n)
 181                fast_forward=f
 182                sha1=$2
 183                ;;
 184        *)
 185                sha1=$1
 186                ;;
 187        esac
 188        sha1=$(git rev-parse $sha1)
 189
 190        if test -f "$DOTEST"/current-commit
 191        then
 192                if test "$fast_forward" = t
 193                then
 194                        cat "$DOTEST"/current-commit | while read current_commit
 195                        do
 196                                git rev-parse HEAD > "$REWRITTEN"/$current_commit
 197                        done
 198                        rm "$DOTEST"/current-commit ||
 199                        die "Cannot write current commit's replacement sha1"
 200                fi
 201        fi
 202
 203        echo $sha1 >> "$DOTEST"/current-commit
 204
 205        # rewrite parents; if none were rewritten, we can fast-forward.
 206        new_parents=
 207        pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
 208        if test "$pend" = " "
 209        then
 210                pend=" root"
 211        fi
 212        while [ "$pend" != "" ]
 213        do
 214                p=$(expr "$pend" : ' \([^ ]*\)')
 215                pend="${pend# $p}"
 216
 217                if test -f "$REWRITTEN"/$p
 218                then
 219                        new_p=$(cat "$REWRITTEN"/$p)
 220
 221                        # If the todo reordered commits, and our parent is marked for
 222                        # rewriting, but hasn't been gotten to yet, assume the user meant to
 223                        # drop it on top of the current HEAD
 224                        if test -z "$new_p"
 225                        then
 226                                new_p=$(git rev-parse HEAD)
 227                        fi
 228
 229                        test $p != $new_p && fast_forward=f
 230                        case "$new_parents" in
 231                        *$new_p*)
 232                                ;; # do nothing; that parent is already there
 233                        *)
 234                                new_parents="$new_parents $new_p"
 235                                ;;
 236                        esac
 237                else
 238                        if test -f "$DROPPED"/$p
 239                        then
 240                                fast_forward=f
 241                                replacement="$(cat "$DROPPED"/$p)"
 242                                test -z "$replacement" && replacement=root
 243                                pend=" $replacement$pend"
 244                        else
 245                                new_parents="$new_parents $p"
 246                        fi
 247                fi
 248        done
 249        case $fast_forward in
 250        t)
 251                output warn "Fast-forward to $sha1"
 252                output git reset --hard $sha1 ||
 253                        die "Cannot fast-forward to $sha1"
 254                ;;
 255        f)
 256                first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
 257
 258                if [ "$1" != "-n" ]
 259                then
 260                        # detach HEAD to current parent
 261                        output git checkout $first_parent 2> /dev/null ||
 262                                die "Cannot move HEAD to $first_parent"
 263                fi
 264
 265                case "$new_parents" in
 266                ' '*' '*)
 267                        test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 268
 269                        # redo merge
 270                        author_script=$(get_author_ident_from_commit $sha1)
 271                        eval "$author_script"
 272                        msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
 273                        # No point in merging the first parent, that's HEAD
 274                        new_parents=${new_parents# $first_parent}
 275                        if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 276                                GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 277                                GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
 278                                output git merge $STRATEGY -m "$msg" \
 279                                        $new_parents
 280                        then
 281                                printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
 282                                die_with_patch $sha1 "Error redoing merge $sha1"
 283                        fi
 284                        ;;
 285                *)
 286                        output git cherry-pick "$@" ||
 287                                die_with_patch $sha1 "Could not pick $sha1"
 288                        ;;
 289                esac
 290                ;;
 291        esac
 292}
 293
 294nth_string () {
 295        case "$1" in
 296        *1[0-9]|*[04-9]) echo "$1"th;;
 297        *1) echo "$1"st;;
 298        *2) echo "$1"nd;;
 299        *3) echo "$1"rd;;
 300        esac
 301}
 302
 303make_squash_message () {
 304        if test -f "$SQUASH_MSG"; then
 305                # We want to be careful about matching only the commit
 306                # message comment lines generated by this function.
 307                # "[snrt][tdh]" matches the nth_string endings.
 308                COUNT=$(($(sed -n "s/^# Th[^0-9]*\([1-9][0-9]*\)[snrt][tdh] commit message.*:/\1/p" \
 309                        < "$SQUASH_MSG" | sed -ne '$p')+1))
 310                echo "# This is a combination of $COUNT commits."
 311                sed -e 1d -e '2,/^./{
 312                        /^$/d
 313                }' <"$SQUASH_MSG"
 314        else
 315                COUNT=2
 316                echo "# This is a combination of two commits."
 317                echo "# The first commit's message is:"
 318                echo
 319                git cat-file commit HEAD | sed -e '1,/^$/d'
 320        fi
 321        case $1 in
 322        squash)
 323                echo
 324                echo "# This is the $(nth_string $COUNT) commit message:"
 325                echo
 326                git cat-file commit $2 | sed -e '1,/^$/d'
 327                ;;
 328        fixup)
 329                echo
 330                echo "# The $(nth_string $COUNT) commit message will be skipped:"
 331                echo
 332                # Comment the lines of the commit message out using
 333                # "#    " rather than "# " to make them less likely to
 334                # confuse the sed regexp above.
 335                git cat-file commit $2 | sed -e '1,/^$/d' -e 's/^/#     /'
 336                ;;
 337        esac
 338}
 339
 340peek_next_command () {
 341        sed -n -e "/^#/d" -e "/^$/d" -e "s/ .*//p" -e "q" < "$TODO"
 342}
 343
 344do_next () {
 345        rm -f "$DOTEST"/message "$DOTEST"/author-script \
 346                "$DOTEST"/amend || exit
 347        read command sha1 rest < "$TODO"
 348        case "$command" in
 349        '#'*|''|noop)
 350                mark_action_done
 351                ;;
 352        pick|p)
 353                comment_for_reflog pick
 354
 355                mark_action_done
 356                pick_one $sha1 ||
 357                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 358                ;;
 359        reword|r)
 360                comment_for_reflog reword
 361
 362                mark_action_done
 363                pick_one $sha1 ||
 364                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 365                git commit --amend
 366                ;;
 367        edit|e)
 368                comment_for_reflog edit
 369
 370                mark_action_done
 371                pick_one $sha1 ||
 372                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 373                make_patch $sha1
 374                git rev-parse --verify HEAD > "$DOTEST"/amend
 375                warn "Stopped at $sha1... $rest"
 376                warn "You can amend the commit now, with"
 377                warn
 378                warn "  git commit --amend"
 379                warn
 380                warn "Once you are satisfied with your changes, run"
 381                warn
 382                warn "  git rebase --continue"
 383                warn
 384                exit 0
 385                ;;
 386        squash|s|fixup|f)
 387                case "$command" in
 388                squash|s)
 389                        squash_style=squash
 390                        ;;
 391                fixup|f)
 392                        squash_style=fixup
 393                        ;;
 394                esac
 395                comment_for_reflog $squash_style
 396
 397                test -f "$DONE" && has_action "$DONE" ||
 398                        die "Cannot '$squash_style' without a previous commit"
 399
 400                mark_action_done
 401                make_squash_message $squash_style $sha1 > "$MSG"
 402                failed=f
 403                author_script=$(get_author_ident_from_commit HEAD)
 404                output git reset --soft HEAD^
 405                pick_one -n $sha1 || failed=t
 406                case "$(peek_next_command)" in
 407                squash|s|fixup|f)
 408                        USE_OUTPUT=output
 409                        MSG_OPT=-F
 410                        EDIT_OR_FILE="$MSG"
 411                        cp "$MSG" "$SQUASH_MSG"
 412                        ;;
 413                *)
 414                        USE_OUTPUT=
 415                        MSG_OPT=
 416                        EDIT_OR_FILE=-e
 417                        rm -f "$SQUASH_MSG" || exit
 418                        cp "$MSG" "$GIT_DIR"/SQUASH_MSG
 419                        rm -f "$GIT_DIR"/MERGE_MSG || exit
 420                        ;;
 421                esac
 422                echo "$author_script" > "$DOTEST"/author-script
 423                if test $failed = f
 424                then
 425                        # This is like --amend, but with a different message
 426                        eval "$author_script"
 427                        GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 428                        GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 429                        GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
 430                        $USE_OUTPUT git commit --no-verify \
 431                                $MSG_OPT "$EDIT_OR_FILE" || failed=t
 432                fi
 433                if test $failed = t
 434                then
 435                        cp "$MSG" "$GIT_DIR"/MERGE_MSG
 436                        warn
 437                        warn "Could not apply $sha1... $rest"
 438                        die_with_patch $sha1 ""
 439                fi
 440                ;;
 441        *)
 442                warn "Unknown command: $command $sha1 $rest"
 443                if git rev-parse --verify -q "$sha1" >/dev/null
 444                then
 445                        die_with_patch $sha1 "Please fix this in the file $TODO."
 446                else
 447                        die "Please fix this in the file $TODO."
 448                fi
 449                ;;
 450        esac
 451        test -s "$TODO" && return
 452
 453        comment_for_reflog finish &&
 454        HEADNAME=$(cat "$DOTEST"/head-name) &&
 455        OLDHEAD=$(cat "$DOTEST"/head) &&
 456        SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
 457        NEWHEAD=$(git rev-parse HEAD) &&
 458        case $HEADNAME in
 459        refs/*)
 460                message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO" &&
 461                git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD &&
 462                git symbolic-ref HEAD $HEADNAME
 463                ;;
 464        esac && {
 465                test ! -f "$DOTEST"/verbose ||
 466                        git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
 467        } &&
 468        rm -rf "$DOTEST" &&
 469        git gc --auto &&
 470        warn "Successfully rebased and updated $HEADNAME."
 471
 472        exit
 473}
 474
 475do_rest () {
 476        while :
 477        do
 478                do_next
 479        done
 480}
 481
 482# skip picking commits whose parents are unchanged
 483skip_unnecessary_picks () {
 484        fd=3
 485        while read command sha1 rest
 486        do
 487                # fd=3 means we skip the command
 488                case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
 489                3,pick,"$ONTO"*|3,p,"$ONTO"*)
 490                        # pick a commit whose parent is current $ONTO -> skip
 491                        ONTO=$sha1
 492                        ;;
 493                3,#*|3,,*)
 494                        # copy comments
 495                        ;;
 496                *)
 497                        fd=1
 498                        ;;
 499                esac
 500                echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
 501        done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
 502        mv -f "$TODO".new "$TODO" ||
 503        die "Could not skip unnecessary pick commands"
 504}
 505
 506# check if no other options are set
 507is_standalone () {
 508        test $# -eq 2 -a "$2" = '--' &&
 509        test -z "$ONTO" &&
 510        test -z "$PRESERVE_MERGES" &&
 511        test -z "$STRATEGY" &&
 512        test -z "$VERBOSE"
 513}
 514
 515get_saved_options () {
 516        test -d "$REWRITTEN" && PRESERVE_MERGES=t
 517        test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 518        test -f "$DOTEST"/verbose && VERBOSE=t
 519        test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
 520}
 521
 522while test $# != 0
 523do
 524        case "$1" in
 525        --no-verify)
 526                OK_TO_SKIP_PRE_REBASE=yes
 527                ;;
 528        --verify)
 529                ;;
 530        --continue)
 531                is_standalone "$@" || usage
 532                get_saved_options
 533                comment_for_reflog continue
 534
 535                test -d "$DOTEST" || die "No interactive rebase running"
 536
 537                # Sanity check
 538                git rev-parse --verify HEAD >/dev/null ||
 539                        die "Cannot read HEAD"
 540                git update-index --ignore-submodules --refresh &&
 541                        git diff-files --quiet --ignore-submodules ||
 542                        die "Working tree is dirty"
 543
 544                # do we have anything to commit?
 545                if git diff-index --cached --quiet --ignore-submodules HEAD --
 546                then
 547                        : Nothing to commit -- skip this
 548                else
 549                        . "$DOTEST"/author-script ||
 550                                die "Cannot find the author identity"
 551                        amend=
 552                        if test -f "$DOTEST"/amend
 553                        then
 554                                amend=$(git rev-parse --verify HEAD)
 555                                test "$amend" = $(cat "$DOTEST"/amend) ||
 556                                die "\
 557You have uncommitted changes in your working tree. Please, commit them
 558first and then run 'git rebase --continue' again."
 559                                git reset --soft HEAD^ ||
 560                                die "Cannot rewind the HEAD"
 561                        fi
 562                        export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE &&
 563                        git commit --no-verify -F "$DOTEST"/message -e || {
 564                                test -n "$amend" && git reset --soft $amend
 565                                die "Could not commit staged changes."
 566                        }
 567                fi
 568
 569                require_clean_work_tree
 570                do_rest
 571                ;;
 572        --abort)
 573                is_standalone "$@" || usage
 574                get_saved_options
 575                comment_for_reflog abort
 576
 577                git rerere clear
 578                test -d "$DOTEST" || die "No interactive rebase running"
 579
 580                HEADNAME=$(cat "$DOTEST"/head-name)
 581                HEAD=$(cat "$DOTEST"/head)
 582                case $HEADNAME in
 583                refs/*)
 584                        git symbolic-ref HEAD $HEADNAME
 585                        ;;
 586                esac &&
 587                output git reset --hard $HEAD &&
 588                rm -rf "$DOTEST"
 589                exit
 590                ;;
 591        --skip)
 592                is_standalone "$@" || usage
 593                get_saved_options
 594                comment_for_reflog skip
 595
 596                git rerere clear
 597                test -d "$DOTEST" || die "No interactive rebase running"
 598
 599                output git reset --hard && do_rest
 600                ;;
 601        -s)
 602                case "$#,$1" in
 603                *,*=*)
 604                        STRATEGY="-s "$(expr "z$1" : 'z-[^=]*=\(.*\)') ;;
 605                1,*)
 606                        usage ;;
 607                *)
 608                        STRATEGY="-s $2"
 609                        shift ;;
 610                esac
 611                ;;
 612        -m)
 613                # we use merge anyway
 614                ;;
 615        -v)
 616                VERBOSE=t
 617                ;;
 618        -p)
 619                PRESERVE_MERGES=t
 620                ;;
 621        -i)
 622                # yeah, we know
 623                ;;
 624        --root)
 625                REBASE_ROOT=t
 626                ;;
 627        --onto)
 628                shift
 629                ONTO=$(git rev-parse --verify "$1") ||
 630                        die "Does not point to a valid commit: $1"
 631                ;;
 632        --)
 633                shift
 634                test -z "$REBASE_ROOT" -a $# -ge 1 -a $# -le 2 ||
 635                test ! -z "$REBASE_ROOT" -a $# -le 1 || usage
 636                test -d "$DOTEST" &&
 637                        die "Interactive rebase already started"
 638
 639                git var GIT_COMMITTER_IDENT >/dev/null ||
 640                        die "You need to set your committer info first"
 641
 642                if test -z "$REBASE_ROOT"
 643                then
 644                        UPSTREAM_ARG="$1"
 645                        UPSTREAM=$(git rev-parse --verify "$1") || die "Invalid base"
 646                        test -z "$ONTO" && ONTO=$UPSTREAM
 647                        shift
 648                else
 649                        UPSTREAM=
 650                        UPSTREAM_ARG=--root
 651                        test -z "$ONTO" &&
 652                                die "You must specify --onto when using --root"
 653                fi
 654                run_pre_rebase_hook "$UPSTREAM_ARG" "$@"
 655
 656                comment_for_reflog start
 657
 658                require_clean_work_tree
 659
 660                if test ! -z "$1"
 661                then
 662                        output git show-ref --verify --quiet "refs/heads/$1" ||
 663                                die "Invalid branchname: $1"
 664                        output git checkout "$1" ||
 665                                die "Could not checkout $1"
 666                fi
 667
 668                HEAD=$(git rev-parse --verify HEAD) || die "No HEAD?"
 669                mkdir "$DOTEST" || die "Could not create temporary $DOTEST"
 670
 671                : > "$DOTEST"/interactive || die "Could not mark as interactive"
 672                git symbolic-ref HEAD > "$DOTEST"/head-name 2> /dev/null ||
 673                        echo "detached HEAD" > "$DOTEST"/head-name
 674
 675                echo $HEAD > "$DOTEST"/head
 676                case "$REBASE_ROOT" in
 677                '')
 678                        rm -f "$DOTEST"/rebase-root ;;
 679                *)
 680                        : >"$DOTEST"/rebase-root ;;
 681                esac
 682                echo $ONTO > "$DOTEST"/onto
 683                test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
 684                test t = "$VERBOSE" && : > "$DOTEST"/verbose
 685                if test t = "$PRESERVE_MERGES"
 686                then
 687                        # $REWRITTEN contains files for each commit that is
 688                        # reachable by at least one merge base of $HEAD and
 689                        # $UPSTREAM. They are not necessarily rewritten, but
 690                        # their children might be.
 691                        # This ensures that commits on merged, but otherwise
 692                        # unrelated side branches are left alone. (Think "X"
 693                        # in the man page's example.)
 694                        if test -z "$REBASE_ROOT"
 695                        then
 696                                mkdir "$REWRITTEN" &&
 697                                for c in $(git merge-base --all $HEAD $UPSTREAM)
 698                                do
 699                                        echo $ONTO > "$REWRITTEN"/$c ||
 700                                                die "Could not init rewritten commits"
 701                                done
 702                        else
 703                                mkdir "$REWRITTEN" &&
 704                                echo $ONTO > "$REWRITTEN"/root ||
 705                                        die "Could not init rewritten commits"
 706                        fi
 707                        # No cherry-pick because our first pass is to determine
 708                        # parents to rewrite and skipping dropped commits would
 709                        # prematurely end our probe
 710                        MERGES_OPTION=
 711                        first_after_upstream="$(git rev-list --reverse --first-parent $UPSTREAM..$HEAD | head -n 1)"
 712                else
 713                        MERGES_OPTION="--no-merges --cherry-pick"
 714                fi
 715
 716                SHORTHEAD=$(git rev-parse --short $HEAD)
 717                SHORTONTO=$(git rev-parse --short $ONTO)
 718                if test -z "$REBASE_ROOT"
 719                        # this is now equivalent to ! -z "$UPSTREAM"
 720                then
 721                        SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
 722                        REVISIONS=$UPSTREAM...$HEAD
 723                        SHORTREVISIONS=$SHORTUPSTREAM..$SHORTHEAD
 724                else
 725                        REVISIONS=$ONTO...$HEAD
 726                        SHORTREVISIONS=$SHORTHEAD
 727                fi
 728                git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 729                        --abbrev=7 --reverse --left-right --topo-order \
 730                        $REVISIONS | \
 731                        sed -n "s/^>//p" | while read shortsha1 rest
 732                do
 733                        if test t != "$PRESERVE_MERGES"
 734                        then
 735                                echo "pick $shortsha1 $rest" >> "$TODO"
 736                        else
 737                                sha1=$(git rev-parse $shortsha1)
 738                                if test -z "$REBASE_ROOT"
 739                                then
 740                                        preserve=t
 741                                        for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
 742                                        do
 743                                                if test -f "$REWRITTEN"/$p -a \( $p != $ONTO -o $sha1 = $first_after_upstream \)
 744                                                then
 745                                                        preserve=f
 746                                                fi
 747                                        done
 748                                else
 749                                        preserve=f
 750                                fi
 751                                if test f = "$preserve"
 752                                then
 753                                        touch "$REWRITTEN"/$sha1
 754                                        echo "pick $shortsha1 $rest" >> "$TODO"
 755                                fi
 756                        fi
 757                done
 758
 759                # Watch for commits that been dropped by --cherry-pick
 760                if test t = "$PRESERVE_MERGES"
 761                then
 762                        mkdir "$DROPPED"
 763                        # Save all non-cherry-picked changes
 764                        git rev-list $REVISIONS --left-right --cherry-pick | \
 765                                sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
 766                        # Now all commits and note which ones are missing in
 767                        # not-cherry-picks and hence being dropped
 768                        git rev-list $REVISIONS |
 769                        while read rev
 770                        do
 771                                if test -f "$REWRITTEN"/$rev -a "$(sane_grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
 772                                then
 773                                        # Use -f2 because if rev-list is telling us this commit is
 774                                        # not worthwhile, we don't want to track its multiple heads,
 775                                        # just the history of its first-parent for others that will
 776                                        # be rebasing on top of it
 777                                        git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
 778                                        short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
 779                                        sane_grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
 780                                        rm "$REWRITTEN"/$rev
 781                                fi
 782                        done
 783                fi
 784
 785                test -s "$TODO" || echo noop >> "$TODO"
 786                cat >> "$TODO" << EOF
 787
 788# Rebase $SHORTREVISIONS onto $SHORTONTO
 789#
 790# Commands:
 791#  p, pick = use commit
 792#  r, reword = use commit, but edit the commit message
 793#  e, edit = use commit, but stop for amending
 794#  s, squash = use commit, but meld into previous commit
 795#  f, fixup = like "squash", but discard this commit's log message
 796#
 797# If you remove a line here THAT COMMIT WILL BE LOST.
 798# However, if you remove everything, the rebase will be aborted.
 799#
 800EOF
 801
 802                has_action "$TODO" ||
 803                        die_abort "Nothing to do"
 804
 805                cp "$TODO" "$TODO".backup
 806                git_editor "$TODO" ||
 807                        die "Could not execute editor"
 808
 809                has_action "$TODO" ||
 810                        die_abort "Nothing to do"
 811
 812                test -d "$REWRITTEN" || skip_unnecessary_picks
 813
 814                git update-ref ORIG_HEAD $HEAD
 815                output git checkout $ONTO && do_rest
 816                ;;
 817        esac
 818        shift
 819done