d8c3c9aac9ecfcc34aac151760520a961f63ce91
   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"
  37
  38# The file containing rebase commands, comments, and empty lines.
  39# This file is created by "git rebase -i" then edited by the user.  As
  40# the lines are processed, they are removed from the front of this
  41# file and written to the tail of $DONE.
  42TODO="$DOTEST"/git-rebase-todo
  43
  44# The rebase command lines that have already been processed.  A line
  45# is moved here when it is first handled, before any associated user
  46# actions.
  47DONE="$DOTEST"/done
  48
  49# The commit message that is planned to be used for any changes that
  50# need to be committed following a user interaction.
  51MSG="$DOTEST"/message
  52
  53# The file into which is accumulated the suggested commit message for
  54# squash/fixup commands.  When the first of a series of squash/fixups
  55# is seen, the file is created and the commit message from the
  56# previous commit and from the first squash/fixup commit are written
  57# to it.  The commit message for each subsequent squash/fixup commit
  58# is appended to the file as it is processed.
  59#
  60# The first line of the file is of the form
  61#     # This is a combination of $COUNT commits.
  62# where $COUNT is the number of commits whose messages have been
  63# written to the file so far (including the initial "pick" commit).
  64# Each time that a commit message is processed, this line is read and
  65# updated.  It is deleted just before the combined commit is made.
  66SQUASH_MSG="$DOTEST"/message-squash
  67
  68# $REWRITTEN is the name of a directory containing files for each
  69# commit that is reachable by at least one merge base of $HEAD and
  70# $UPSTREAM. They are not necessarily rewritten, but their children
  71# might be.  This ensures that commits on merged, but otherwise
  72# unrelated side branches are left alone. (Think "X" in the man page's
  73# example.)
  74REWRITTEN="$DOTEST"/rewritten
  75
  76DROPPED="$DOTEST"/dropped
  77
  78# A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
  79# GIT_AUTHOR_DATE that will be used for the commit that is currently
  80# being rebased.
  81AUTHOR_SCRIPT="$DOTEST"/author-script
  82
  83# When an "edit" rebase command is being processed, the SHA1 of the
  84# commit to be edited is recorded in this file.  When "git rebase
  85# --continue" is executed, if there are any staged changes then they
  86# will be amended to the HEAD commit, but only provided the HEAD
  87# commit is still the commit to be edited.  When any other rebase
  88# command is processed, this file is deleted.
  89AMEND="$DOTEST"/amend
  90
  91PRESERVE_MERGES=
  92STRATEGY=
  93ONTO=
  94VERBOSE=
  95OK_TO_SKIP_PRE_REBASE=
  96REBASE_ROOT=
  97
  98GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
  99mark the corrected paths with 'git add <paths>', and
 100run 'git rebase --continue'"
 101export GIT_CHERRY_PICK_HELP
 102
 103warn () {
 104        echo "$*" >&2
 105}
 106
 107output () {
 108        case "$VERBOSE" in
 109        '')
 110                output=$("$@" 2>&1 )
 111                status=$?
 112                test $status != 0 && printf "%s\n" "$output"
 113                return $status
 114                ;;
 115        *)
 116                "$@"
 117                ;;
 118        esac
 119}
 120
 121# Output the commit message for the specified commit.
 122commit_message () {
 123        git cat-file commit "$1" | sed "1,/^$/d"
 124}
 125
 126run_pre_rebase_hook () {
 127        if test -z "$OK_TO_SKIP_PRE_REBASE" &&
 128           test -x "$GIT_DIR/hooks/pre-rebase"
 129        then
 130                "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
 131                        echo >&2 "The pre-rebase hook refused to rebase."
 132                        exit 1
 133                }
 134        fi
 135}
 136
 137require_clean_work_tree () {
 138        # test if working tree is dirty
 139        git rev-parse --verify HEAD > /dev/null &&
 140        git update-index --ignore-submodules --refresh &&
 141        git diff-files --quiet --ignore-submodules &&
 142        git diff-index --cached --quiet HEAD --ignore-submodules -- ||
 143        die "Working tree is dirty"
 144}
 145
 146ORIG_REFLOG_ACTION="$GIT_REFLOG_ACTION"
 147
 148comment_for_reflog () {
 149        case "$ORIG_REFLOG_ACTION" in
 150        ''|rebase*)
 151                GIT_REFLOG_ACTION="rebase -i ($1)"
 152                export GIT_REFLOG_ACTION
 153                ;;
 154        esac
 155}
 156
 157last_count=
 158mark_action_done () {
 159        sed -e 1q < "$TODO" >> "$DONE"
 160        sed -e 1d < "$TODO" >> "$TODO".new
 161        mv -f "$TODO".new "$TODO"
 162        count=$(sane_grep -c '^[^#]' < "$DONE")
 163        total=$(($count+$(sane_grep -c '^[^#]' < "$TODO")))
 164        if test "$last_count" != "$count"
 165        then
 166                last_count=$count
 167                printf "Rebasing (%d/%d)\r" $count $total
 168                test -z "$VERBOSE" || echo
 169        fi
 170}
 171
 172make_patch () {
 173        sha1_and_parents="$(git rev-list --parents -1 "$1")"
 174        case "$sha1_and_parents" in
 175        ?*' '?*' '?*)
 176                git diff --cc $sha1_and_parents
 177                ;;
 178        ?*' '?*)
 179                git diff-tree -p "$1^!"
 180                ;;
 181        *)
 182                echo "Root commit"
 183                ;;
 184        esac > "$DOTEST"/patch
 185        test -f "$MSG" ||
 186                commit_message "$1" > "$MSG"
 187        test -f "$AUTHOR_SCRIPT" ||
 188                get_author_ident_from_commit "$1" > "$AUTHOR_SCRIPT"
 189}
 190
 191die_with_patch () {
 192        make_patch "$1"
 193        git rerere
 194        die "$2"
 195}
 196
 197die_abort () {
 198        rm -rf "$DOTEST"
 199        die "$1"
 200}
 201
 202has_action () {
 203        sane_grep '^[^#]' "$1" >/dev/null
 204}
 205
 206# Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
 207# GIT_AUTHOR_DATE exported from the current environment.
 208do_with_author () {
 209        GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 210        GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 211        GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
 212        "$@"
 213}
 214
 215pick_one () {
 216        no_ff=
 217        case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
 218        output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
 219        test -d "$REWRITTEN" &&
 220                pick_one_preserving_merges "$@" && return
 221        if test -n "$REBASE_ROOT"
 222        then
 223                output git cherry-pick "$@"
 224                return
 225        fi
 226        parent_sha1=$(git rev-parse --verify $sha1^) ||
 227                die "Could not get the parent of $sha1"
 228        current_sha1=$(git rev-parse --verify HEAD)
 229        if test -z "$no_ff" -a "$current_sha1" = "$parent_sha1"
 230        then
 231                output git reset --hard $sha1
 232                output warn Fast-forward to $(git rev-parse --short $sha1)
 233        else
 234                output git cherry-pick "$@"
 235        fi
 236}
 237
 238pick_one_preserving_merges () {
 239        fast_forward=t
 240        case "$1" in
 241        -n)
 242                fast_forward=f
 243                sha1=$2
 244                ;;
 245        *)
 246                sha1=$1
 247                ;;
 248        esac
 249        sha1=$(git rev-parse $sha1)
 250
 251        if test -f "$DOTEST"/current-commit
 252        then
 253                if test "$fast_forward" = t
 254                then
 255                        cat "$DOTEST"/current-commit | while read current_commit
 256                        do
 257                                git rev-parse HEAD > "$REWRITTEN"/$current_commit
 258                        done
 259                        rm "$DOTEST"/current-commit ||
 260                        die "Cannot write current commit's replacement sha1"
 261                fi
 262        fi
 263
 264        echo $sha1 >> "$DOTEST"/current-commit
 265
 266        # rewrite parents; if none were rewritten, we can fast-forward.
 267        new_parents=
 268        pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
 269        if test "$pend" = " "
 270        then
 271                pend=" root"
 272        fi
 273        while [ "$pend" != "" ]
 274        do
 275                p=$(expr "$pend" : ' \([^ ]*\)')
 276                pend="${pend# $p}"
 277
 278                if test -f "$REWRITTEN"/$p
 279                then
 280                        new_p=$(cat "$REWRITTEN"/$p)
 281
 282                        # If the todo reordered commits, and our parent is marked for
 283                        # rewriting, but hasn't been gotten to yet, assume the user meant to
 284                        # drop it on top of the current HEAD
 285                        if test -z "$new_p"
 286                        then
 287                                new_p=$(git rev-parse HEAD)
 288                        fi
 289
 290                        test $p != $new_p && fast_forward=f
 291                        case "$new_parents" in
 292                        *$new_p*)
 293                                ;; # do nothing; that parent is already there
 294                        *)
 295                                new_parents="$new_parents $new_p"
 296                                ;;
 297                        esac
 298                else
 299                        if test -f "$DROPPED"/$p
 300                        then
 301                                fast_forward=f
 302                                replacement="$(cat "$DROPPED"/$p)"
 303                                test -z "$replacement" && replacement=root
 304                                pend=" $replacement$pend"
 305                        else
 306                                new_parents="$new_parents $p"
 307                        fi
 308                fi
 309        done
 310        case $fast_forward in
 311        t)
 312                output warn "Fast-forward to $sha1"
 313                output git reset --hard $sha1 ||
 314                        die "Cannot fast-forward to $sha1"
 315                ;;
 316        f)
 317                first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
 318
 319                if [ "$1" != "-n" ]
 320                then
 321                        # detach HEAD to current parent
 322                        output git checkout $first_parent 2> /dev/null ||
 323                                die "Cannot move HEAD to $first_parent"
 324                fi
 325
 326                case "$new_parents" in
 327                ' '*' '*)
 328                        test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 329
 330                        # redo merge
 331                        author_script=$(get_author_ident_from_commit $sha1)
 332                        eval "$author_script"
 333                        msg="$(commit_message $sha1)"
 334                        # No point in merging the first parent, that's HEAD
 335                        new_parents=${new_parents# $first_parent}
 336                        if ! do_with_author output \
 337                                git merge $STRATEGY -m "$msg" $new_parents
 338                        then
 339                                printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
 340                                die_with_patch $sha1 "Error redoing merge $sha1"
 341                        fi
 342                        ;;
 343                *)
 344                        output git cherry-pick "$@" ||
 345                                die_with_patch $sha1 "Could not pick $sha1"
 346                        ;;
 347                esac
 348                ;;
 349        esac
 350}
 351
 352nth_string () {
 353        case "$1" in
 354        *1[0-9]|*[04-9]) echo "$1"th;;
 355        *1) echo "$1"st;;
 356        *2) echo "$1"nd;;
 357        *3) echo "$1"rd;;
 358        esac
 359}
 360
 361update_squash_message () {
 362        if test -f "$SQUASH_MSG"; then
 363                mv "$SQUASH_MSG" "$SQUASH_MSG".bak || exit
 364                COUNT=$(($(sed -n \
 365                        -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
 366                        -e "q" < "$SQUASH_MSG".bak)+1))
 367                {
 368                        echo "# This is a combination of $COUNT commits."
 369                        sed -e 1d -e '2,/^./{
 370                                /^$/d
 371                        }' <"$SQUASH_MSG".bak
 372                } >$SQUASH_MSG
 373        else
 374                COUNT=2
 375                {
 376                        echo "# This is a combination of 2 commits."
 377                        echo "# The first commit's message is:"
 378                        echo
 379                        commit_message HEAD
 380                } >$SQUASH_MSG
 381        fi
 382        case $1 in
 383        squash)
 384                echo
 385                echo "# This is the $(nth_string $COUNT) commit message:"
 386                echo
 387                commit_message $2
 388                ;;
 389        fixup)
 390                echo
 391                echo "# The $(nth_string $COUNT) commit message will be skipped:"
 392                echo
 393                commit_message $2 | sed -e 's/^/#       /'
 394                ;;
 395        esac >>$SQUASH_MSG
 396}
 397
 398peek_next_command () {
 399        sed -n -e "/^#/d" -e "/^$/d" -e "s/ .*//p" -e "q" < "$TODO"
 400}
 401
 402do_next () {
 403        rm -f "$MSG" "$AUTHOR_SCRIPT" "$AMEND" || exit
 404        read command sha1 rest < "$TODO"
 405        case "$command" in
 406        '#'*|''|noop)
 407                mark_action_done
 408                ;;
 409        pick|p)
 410                comment_for_reflog pick
 411
 412                mark_action_done
 413                pick_one $sha1 ||
 414                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 415                ;;
 416        reword|r)
 417                comment_for_reflog reword
 418
 419                mark_action_done
 420                pick_one $sha1 ||
 421                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 422                git commit --amend
 423                ;;
 424        edit|e)
 425                comment_for_reflog edit
 426
 427                mark_action_done
 428                pick_one $sha1 ||
 429                        die_with_patch $sha1 "Could not apply $sha1... $rest"
 430                make_patch $sha1
 431                git rev-parse --verify HEAD > "$AMEND"
 432                warn "Stopped at $sha1... $rest"
 433                warn "You can amend the commit now, with"
 434                warn
 435                warn "  git commit --amend"
 436                warn
 437                warn "Once you are satisfied with your changes, run"
 438                warn
 439                warn "  git rebase --continue"
 440                warn
 441                exit 0
 442                ;;
 443        squash|s|fixup|f)
 444                case "$command" in
 445                squash|s)
 446                        squash_style=squash
 447                        ;;
 448                fixup|f)
 449                        squash_style=fixup
 450                        ;;
 451                esac
 452                comment_for_reflog $squash_style
 453
 454                test -f "$DONE" && has_action "$DONE" ||
 455                        die "Cannot '$squash_style' without a previous commit"
 456
 457                mark_action_done
 458                update_squash_message $squash_style $sha1
 459                failed=f
 460                author_script=$(get_author_ident_from_commit HEAD)
 461                echo "$author_script" > "$AUTHOR_SCRIPT"
 462                eval "$author_script"
 463                output git reset --soft HEAD^
 464                pick_one -n $sha1 || failed=t
 465                case "$(peek_next_command)" in
 466                squash|s|fixup|f)
 467                        USE_OUTPUT=output
 468                        cp "$SQUASH_MSG" "$MSG" || exit
 469                        MSG_OPT=-F
 470                        EDIT_OR_FILE="$MSG"
 471                        ;;
 472                *)
 473                        USE_OUTPUT=
 474                        MSG_OPT=
 475                        EDIT_OR_FILE=-e
 476                        cp "$SQUASH_MSG" "$MSG" || exit
 477                        mv "$SQUASH_MSG" "$GIT_DIR"/SQUASH_MSG || exit
 478                        rm -f "$GIT_DIR"/MERGE_MSG || exit
 479                        ;;
 480                esac
 481                if test $failed = f
 482                then
 483                        # This is like --amend, but with a different message
 484                        do_with_author $USE_OUTPUT git commit --no-verify \
 485                                $MSG_OPT "$EDIT_OR_FILE" ||
 486                                failed=t
 487                fi
 488                if test $failed = t
 489                then
 490                        cp "$MSG" "$GIT_DIR"/MERGE_MSG
 491                        warn
 492                        warn "Could not apply $sha1... $rest"
 493                        die_with_patch $sha1 ""
 494                fi
 495                ;;
 496        *)
 497                warn "Unknown command: $command $sha1 $rest"
 498                if git rev-parse --verify -q "$sha1" >/dev/null
 499                then
 500                        die_with_patch $sha1 "Please fix this in the file $TODO."
 501                else
 502                        die "Please fix this in the file $TODO."
 503                fi
 504                ;;
 505        esac
 506        test -s "$TODO" && return
 507
 508        comment_for_reflog finish &&
 509        HEADNAME=$(cat "$DOTEST"/head-name) &&
 510        OLDHEAD=$(cat "$DOTEST"/head) &&
 511        SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
 512        NEWHEAD=$(git rev-parse HEAD) &&
 513        case $HEADNAME in
 514        refs/*)
 515                message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO" &&
 516                git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD &&
 517                git symbolic-ref HEAD $HEADNAME
 518                ;;
 519        esac && {
 520                test ! -f "$DOTEST"/verbose ||
 521                        git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
 522        } &&
 523        rm -rf "$DOTEST" &&
 524        git gc --auto &&
 525        warn "Successfully rebased and updated $HEADNAME."
 526
 527        exit
 528}
 529
 530do_rest () {
 531        while :
 532        do
 533                do_next
 534        done
 535}
 536
 537# skip picking commits whose parents are unchanged
 538skip_unnecessary_picks () {
 539        fd=3
 540        while read command sha1 rest
 541        do
 542                # fd=3 means we skip the command
 543                case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
 544                3,pick,"$ONTO"*|3,p,"$ONTO"*)
 545                        # pick a commit whose parent is current $ONTO -> skip
 546                        ONTO=$sha1
 547                        ;;
 548                3,#*|3,,*)
 549                        # copy comments
 550                        ;;
 551                *)
 552                        fd=1
 553                        ;;
 554                esac
 555                echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
 556        done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
 557        mv -f "$TODO".new "$TODO" ||
 558        die "Could not skip unnecessary pick commands"
 559}
 560
 561# check if no other options are set
 562is_standalone () {
 563        test $# -eq 2 -a "$2" = '--' &&
 564        test -z "$ONTO" &&
 565        test -z "$PRESERVE_MERGES" &&
 566        test -z "$STRATEGY" &&
 567        test -z "$VERBOSE"
 568}
 569
 570get_saved_options () {
 571        test -d "$REWRITTEN" && PRESERVE_MERGES=t
 572        test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 573        test -f "$DOTEST"/verbose && VERBOSE=t
 574        test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
 575}
 576
 577while test $# != 0
 578do
 579        case "$1" in
 580        --no-verify)
 581                OK_TO_SKIP_PRE_REBASE=yes
 582                ;;
 583        --verify)
 584                ;;
 585        --continue)
 586                is_standalone "$@" || usage
 587                get_saved_options
 588                comment_for_reflog continue
 589
 590                test -d "$DOTEST" || die "No interactive rebase running"
 591
 592                # Sanity check
 593                git rev-parse --verify HEAD >/dev/null ||
 594                        die "Cannot read HEAD"
 595                git update-index --ignore-submodules --refresh &&
 596                        git diff-files --quiet --ignore-submodules ||
 597                        die "Working tree is dirty"
 598
 599                # do we have anything to commit?
 600                if git diff-index --cached --quiet --ignore-submodules HEAD --
 601                then
 602                        : Nothing to commit -- skip this
 603                else
 604                        . "$AUTHOR_SCRIPT" ||
 605                                die "Cannot find the author identity"
 606                        amend=
 607                        if test -f "$AMEND"
 608                        then
 609                                amend=$(git rev-parse --verify HEAD)
 610                                test "$amend" = $(cat "$AMEND") ||
 611                                die "\
 612You have uncommitted changes in your working tree. Please, commit them
 613first and then run 'git rebase --continue' again."
 614                                git reset --soft HEAD^ ||
 615                                die "Cannot rewind the HEAD"
 616                        fi
 617                        do_with_author git commit --no-verify -F "$MSG" -e || {
 618                                test -n "$amend" && git reset --soft $amend
 619                                die "Could not commit staged changes."
 620                        }
 621                fi
 622
 623                require_clean_work_tree
 624                do_rest
 625                ;;
 626        --abort)
 627                is_standalone "$@" || usage
 628                get_saved_options
 629                comment_for_reflog abort
 630
 631                git rerere clear
 632                test -d "$DOTEST" || die "No interactive rebase running"
 633
 634                HEADNAME=$(cat "$DOTEST"/head-name)
 635                HEAD=$(cat "$DOTEST"/head)
 636                case $HEADNAME in
 637                refs/*)
 638                        git symbolic-ref HEAD $HEADNAME
 639                        ;;
 640                esac &&
 641                output git reset --hard $HEAD &&
 642                rm -rf "$DOTEST"
 643                exit
 644                ;;
 645        --skip)
 646                is_standalone "$@" || usage
 647                get_saved_options
 648                comment_for_reflog skip
 649
 650                git rerere clear
 651                test -d "$DOTEST" || die "No interactive rebase running"
 652
 653                output git reset --hard && do_rest
 654                ;;
 655        -s)
 656                case "$#,$1" in
 657                *,*=*)
 658                        STRATEGY="-s "$(expr "z$1" : 'z-[^=]*=\(.*\)') ;;
 659                1,*)
 660                        usage ;;
 661                *)
 662                        STRATEGY="-s $2"
 663                        shift ;;
 664                esac
 665                ;;
 666        -m)
 667                # we use merge anyway
 668                ;;
 669        -v)
 670                VERBOSE=t
 671                ;;
 672        -p)
 673                PRESERVE_MERGES=t
 674                ;;
 675        -i)
 676                # yeah, we know
 677                ;;
 678        --root)
 679                REBASE_ROOT=t
 680                ;;
 681        --onto)
 682                shift
 683                ONTO=$(git rev-parse --verify "$1") ||
 684                        die "Does not point to a valid commit: $1"
 685                ;;
 686        --)
 687                shift
 688                test -z "$REBASE_ROOT" -a $# -ge 1 -a $# -le 2 ||
 689                test ! -z "$REBASE_ROOT" -a $# -le 1 || usage
 690                test -d "$DOTEST" &&
 691                        die "Interactive rebase already started"
 692
 693                git var GIT_COMMITTER_IDENT >/dev/null ||
 694                        die "You need to set your committer info first"
 695
 696                if test -z "$REBASE_ROOT"
 697                then
 698                        UPSTREAM_ARG="$1"
 699                        UPSTREAM=$(git rev-parse --verify "$1") || die "Invalid base"
 700                        test -z "$ONTO" && ONTO=$UPSTREAM
 701                        shift
 702                else
 703                        UPSTREAM=
 704                        UPSTREAM_ARG=--root
 705                        test -z "$ONTO" &&
 706                                die "You must specify --onto when using --root"
 707                fi
 708                run_pre_rebase_hook "$UPSTREAM_ARG" "$@"
 709
 710                comment_for_reflog start
 711
 712                require_clean_work_tree
 713
 714                if test ! -z "$1"
 715                then
 716                        output git show-ref --verify --quiet "refs/heads/$1" ||
 717                                die "Invalid branchname: $1"
 718                        output git checkout "$1" ||
 719                                die "Could not checkout $1"
 720                fi
 721
 722                HEAD=$(git rev-parse --verify HEAD) || die "No HEAD?"
 723                mkdir "$DOTEST" || die "Could not create temporary $DOTEST"
 724
 725                : > "$DOTEST"/interactive || die "Could not mark as interactive"
 726                git symbolic-ref HEAD > "$DOTEST"/head-name 2> /dev/null ||
 727                        echo "detached HEAD" > "$DOTEST"/head-name
 728
 729                echo $HEAD > "$DOTEST"/head
 730                case "$REBASE_ROOT" in
 731                '')
 732                        rm -f "$DOTEST"/rebase-root ;;
 733                *)
 734                        : >"$DOTEST"/rebase-root ;;
 735                esac
 736                echo $ONTO > "$DOTEST"/onto
 737                test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
 738                test t = "$VERBOSE" && : > "$DOTEST"/verbose
 739                if test t = "$PRESERVE_MERGES"
 740                then
 741                        if test -z "$REBASE_ROOT"
 742                        then
 743                                mkdir "$REWRITTEN" &&
 744                                for c in $(git merge-base --all $HEAD $UPSTREAM)
 745                                do
 746                                        echo $ONTO > "$REWRITTEN"/$c ||
 747                                                die "Could not init rewritten commits"
 748                                done
 749                        else
 750                                mkdir "$REWRITTEN" &&
 751                                echo $ONTO > "$REWRITTEN"/root ||
 752                                        die "Could not init rewritten commits"
 753                        fi
 754                        # No cherry-pick because our first pass is to determine
 755                        # parents to rewrite and skipping dropped commits would
 756                        # prematurely end our probe
 757                        MERGES_OPTION=
 758                        first_after_upstream="$(git rev-list --reverse --first-parent $UPSTREAM..$HEAD | head -n 1)"
 759                else
 760                        MERGES_OPTION="--no-merges --cherry-pick"
 761                fi
 762
 763                SHORTHEAD=$(git rev-parse --short $HEAD)
 764                SHORTONTO=$(git rev-parse --short $ONTO)
 765                if test -z "$REBASE_ROOT"
 766                        # this is now equivalent to ! -z "$UPSTREAM"
 767                then
 768                        SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
 769                        REVISIONS=$UPSTREAM...$HEAD
 770                        SHORTREVISIONS=$SHORTUPSTREAM..$SHORTHEAD
 771                else
 772                        REVISIONS=$ONTO...$HEAD
 773                        SHORTREVISIONS=$SHORTHEAD
 774                fi
 775                git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 776                        --abbrev=7 --reverse --left-right --topo-order \
 777                        $REVISIONS | \
 778                        sed -n "s/^>//p" | while read shortsha1 rest
 779                do
 780                        if test t != "$PRESERVE_MERGES"
 781                        then
 782                                echo "pick $shortsha1 $rest" >> "$TODO"
 783                        else
 784                                sha1=$(git rev-parse $shortsha1)
 785                                if test -z "$REBASE_ROOT"
 786                                then
 787                                        preserve=t
 788                                        for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
 789                                        do
 790                                                if test -f "$REWRITTEN"/$p -a \( $p != $ONTO -o $sha1 = $first_after_upstream \)
 791                                                then
 792                                                        preserve=f
 793                                                fi
 794                                        done
 795                                else
 796                                        preserve=f
 797                                fi
 798                                if test f = "$preserve"
 799                                then
 800                                        touch "$REWRITTEN"/$sha1
 801                                        echo "pick $shortsha1 $rest" >> "$TODO"
 802                                fi
 803                        fi
 804                done
 805
 806                # Watch for commits that been dropped by --cherry-pick
 807                if test t = "$PRESERVE_MERGES"
 808                then
 809                        mkdir "$DROPPED"
 810                        # Save all non-cherry-picked changes
 811                        git rev-list $REVISIONS --left-right --cherry-pick | \
 812                                sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
 813                        # Now all commits and note which ones are missing in
 814                        # not-cherry-picks and hence being dropped
 815                        git rev-list $REVISIONS |
 816                        while read rev
 817                        do
 818                                if test -f "$REWRITTEN"/$rev -a "$(sane_grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
 819                                then
 820                                        # Use -f2 because if rev-list is telling us this commit is
 821                                        # not worthwhile, we don't want to track its multiple heads,
 822                                        # just the history of its first-parent for others that will
 823                                        # be rebasing on top of it
 824                                        git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
 825                                        short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
 826                                        sane_grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
 827                                        rm "$REWRITTEN"/$rev
 828                                fi
 829                        done
 830                fi
 831
 832                test -s "$TODO" || echo noop >> "$TODO"
 833                cat >> "$TODO" << EOF
 834
 835# Rebase $SHORTREVISIONS onto $SHORTONTO
 836#
 837# Commands:
 838#  p, pick = use commit
 839#  r, reword = use commit, but edit the commit message
 840#  e, edit = use commit, but stop for amending
 841#  s, squash = use commit, but meld into previous commit
 842#  f, fixup = like "squash", but discard this commit's log message
 843#
 844# If you remove a line here THAT COMMIT WILL BE LOST.
 845# However, if you remove everything, the rebase will be aborted.
 846#
 847EOF
 848
 849                has_action "$TODO" ||
 850                        die_abort "Nothing to do"
 851
 852                cp "$TODO" "$TODO".backup
 853                git_editor "$TODO" ||
 854                        die "Could not execute editor"
 855
 856                has_action "$TODO" ||
 857                        die_abort "Nothing to do"
 858
 859                test -d "$REWRITTEN" || skip_unnecessary_picks
 860
 861                git update-ref ORIG_HEAD $HEAD
 862                output git checkout $ONTO && do_rest
 863                ;;
 864        esac
 865        shift
 866done