Andrew's git / gitweb.git / git-legacy-rebase.sh
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git-legacy-rebase.shon commit tree-walk: copy object ID before use (0a3faa4)
   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano.
   4#
   5
   6SUBDIRECTORY_OK=Yes
   7OPTIONS_KEEPDASHDASH=
   8OPTIONS_STUCKLONG=t
   9OPTIONS_SPEC="\
  10git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] [<upstream>] [<branch>]
  11git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] --root [<branch>]
  12git rebase --continue | --abort | --skip | --edit-todo
  13--
  14 Available options are
  15v,verbose!         display a diffstat of what changed upstream
  16q,quiet!           be quiet. implies --no-stat
  17autostash          automatically stash/stash pop before and after
  18fork-point         use 'merge-base --fork-point' to refine upstream
  19onto=!             rebase onto given branch instead of upstream
  20r,rebase-merges?   try to rebase merges instead of skipping them
  21p,preserve-merges! try to recreate merges instead of ignoring them
  22s,strategy=!       use the given merge strategy
  23X,strategy-option=! pass the argument through to the merge strategy
  24no-ff!             cherry-pick all commits, even if unchanged
  25f,force-rebase!    cherry-pick all commits, even if unchanged
  26m,merge!           use merging strategies to rebase
  27i,interactive!     let the user edit the list of commits to rebase
  28x,exec=!           add exec lines after each commit of the editable list
  29k,keep-empty       preserve empty commits during rebase
  30allow-empty-message allow rebasing commits with empty messages
  31stat!              display a diffstat of what changed upstream
  32n,no-stat!         do not show diffstat of what changed upstream
  33verify             allow pre-rebase hook to run
  34rerere-autoupdate  allow rerere to update index with resolved conflicts
  35root!              rebase all reachable commits up to the root(s)
  36autosquash         move commits that begin with squash!/fixup! under -i
  37signoff            add a Signed-off-by: line to each commit
  38committer-date-is-author-date! passed to 'git am'
  39ignore-date!       passed to 'git am'
  40whitespace=!       passed to 'git apply'
  41ignore-whitespace! passed to 'git apply'
  42C=!                passed to 'git apply'
  43S,gpg-sign?        GPG-sign commits
  44 Actions:
  45continue!          continue
  46abort!             abort and check out the original branch
  47skip!              skip current patch and continue
  48edit-todo!         edit the todo list during an interactive rebase
  49quit!              abort but keep HEAD where it is
  50show-current-patch! show the patch file being applied or merged
  51"
  52. git-sh-setup
  53set_reflog_action rebase
  54require_work_tree_exists
  55cd_to_toplevel
  56
  57LF='
  58'
  59ok_to_skip_pre_rebase=
  60
  61squash_onto=
  62unset onto
  63unset restrict_revision
  64cmd=
  65strategy=
  66strategy_opts=
  67do_merge=
  68merge_dir="$GIT_DIR"/rebase-merge
  69apply_dir="$GIT_DIR"/rebase-apply
  70verbose=
  71diffstat=
  72test "$(git config --bool rebase.stat)" = true && diffstat=t
  73autostash="$(git config --bool rebase.autostash || echo false)"
  74fork_point=auto
  75git_am_opt=
  76git_format_patch_opt=
  77rebase_root=
  78force_rebase=
  79allow_rerere_autoupdate=
  80# Non-empty if a rebase was in progress when 'git rebase' was invoked
  81in_progress=
  82# One of {am, merge, interactive}
  83type=
  84# One of {"$GIT_DIR"/rebase-apply, "$GIT_DIR"/rebase-merge}
  85state_dir=
  86# One of {'', continue, skip, abort}, as parsed from command line
  87action=
  88rebase_merges=
  89rebase_cousins=
  90preserve_merges=
  91autosquash=
  92keep_empty=
  93allow_empty_message=--allow-empty-message
  94signoff=
  95test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
  96case "$(git config --bool commit.gpgsign)" in
  97true)   gpg_sign_opt=-S ;;
  98*)      gpg_sign_opt= ;;
  99esac
 100. git-rebase--common
 101
 102read_basic_state () {
 103        test -f "$state_dir/head-name" &&
 104        test -f "$state_dir/onto" &&
 105        head_name=$(cat "$state_dir"/head-name) &&
 106        onto=$(cat "$state_dir"/onto) &&
 107        # We always write to orig-head, but interactive rebase used to write to
 108        # head. Fall back to reading from head to cover for the case that the
 109        # user upgraded git with an ongoing interactive rebase.
 110        if test -f "$state_dir"/orig-head
 111        then
 112                orig_head=$(cat "$state_dir"/orig-head)
 113        else
 114                orig_head=$(cat "$state_dir"/head)
 115        fi &&
 116        GIT_QUIET=$(cat "$state_dir"/quiet) &&
 117        test -f "$state_dir"/verbose && verbose=t
 118        test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
 119        test -f "$state_dir"/strategy_opts &&
 120                strategy_opts="$(cat "$state_dir"/strategy_opts)"
 121        test -f "$state_dir"/allow_rerere_autoupdate &&
 122                allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
 123        test -f "$state_dir"/gpg_sign_opt &&
 124                gpg_sign_opt="$(cat "$state_dir"/gpg_sign_opt)"
 125        test -f "$state_dir"/signoff && {
 126                signoff="$(cat "$state_dir"/signoff)"
 127                force_rebase=t
 128        }
 129}
 130
 131finish_rebase () {
 132        rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 133        apply_autostash &&
 134        { git gc --auto || true; } &&
 135        rm -rf "$state_dir"
 136}
 137
 138run_interactive () {
 139        GIT_CHERRY_PICK_HELP="$resolvemsg"
 140        export GIT_CHERRY_PICK_HELP
 141
 142        test -n "$keep_empty" && keep_empty="--keep-empty"
 143        test -n "$rebase_merges" && rebase_merges="--rebase-merges"
 144        test -n "$rebase_cousins" && rebase_cousins="--rebase-cousins"
 145        test -n "$autosquash" && autosquash="--autosquash"
 146        test -n "$verbose" && verbose="--verbose"
 147        test -n "$force_rebase" && force_rebase="--no-ff"
 148        test -n "$restrict_revision" && \
 149                restrict_revision="--restrict-revision=^$restrict_revision"
 150        test -n "$upstream" && upstream="--upstream=$upstream"
 151        test -n "$onto" && onto="--onto=$onto"
 152        test -n "$squash_onto" && squash_onto="--squash-onto=$squash_onto"
 153        test -n "$onto_name" && onto_name="--onto-name=$onto_name"
 154        test -n "$head_name" && head_name="--head-name=$head_name"
 155        test -n "$strategy" && strategy="--strategy=$strategy"
 156        test -n "$strategy_opts" && strategy_opts="--strategy-opts=$strategy_opts"
 157        test -n "$switch_to" && switch_to="--switch-to=$switch_to"
 158        test -n "$cmd" && cmd="--cmd=$cmd"
 159        test -n "$action" && action="--$action"
 160
 161        exec git rebase--interactive "$action" "$keep_empty" "$rebase_merges" "$rebase_cousins" \
 162                "$upstream" "$onto" "$squash_onto" "$restrict_revision" \
 163                "$allow_empty_message" "$autosquash" "$verbose" \
 164                "$force_rebase" "$onto_name" "$head_name" "$strategy" \
 165                "$strategy_opts" "$cmd" "$switch_to" \
 166                "$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff"
 167}
 168
 169run_specific_rebase () {
 170        if [ "$interactive_rebase" = implied ]; then
 171                GIT_EDITOR=:
 172                export GIT_EDITOR
 173                autosquash=
 174        fi
 175
 176        if test -n "$interactive_rebase" -a -z "$preserve_merges"
 177        then
 178                run_interactive
 179        else
 180                . git-rebase--$type
 181
 182                if test -z "$preserve_merges"
 183                then
 184                        git_rebase__$type
 185                else
 186                        git_rebase__preserve_merges
 187                fi
 188        fi
 189
 190        ret=$?
 191        if test $ret -eq 0
 192        then
 193                finish_rebase
 194        elif test $ret -eq 2 # special exit status for rebase -p
 195        then
 196                apply_autostash &&
 197                rm -rf "$state_dir" &&
 198                die "Nothing to do"
 199        fi
 200        exit $ret
 201}
 202
 203run_pre_rebase_hook () {
 204        if test -z "$ok_to_skip_pre_rebase" &&
 205           test -x "$(git rev-parse --git-path hooks/pre-rebase)"
 206        then
 207                "$(git rev-parse --git-path hooks/pre-rebase)" ${1+"$@"} ||
 208                die "$(gettext "The pre-rebase hook refused to rebase.")"
 209        fi
 210}
 211
 212test -f "$apply_dir"/applying &&
 213        die "$(gettext "It looks like 'git am' is in progress. Cannot rebase.")"
 214
 215if test -d "$apply_dir"
 216then
 217        type=am
 218        state_dir="$apply_dir"
 219elif test -d "$merge_dir"
 220then
 221        if test -d "$merge_dir"/rewritten
 222        then
 223                type=preserve-merges
 224                interactive_rebase=explicit
 225                preserve_merges=t
 226        elif test -f "$merge_dir"/interactive
 227        then
 228                type=interactive
 229                interactive_rebase=explicit
 230        else
 231                type=merge
 232        fi
 233        state_dir="$merge_dir"
 234fi
 235test -n "$type" && in_progress=t
 236
 237total_argc=$#
 238while test $# != 0
 239do
 240        case "$1" in
 241        --no-verify)
 242                ok_to_skip_pre_rebase=yes
 243                ;;
 244        --verify)
 245                ok_to_skip_pre_rebase=
 246                ;;
 247        --continue|--skip|--abort|--quit|--edit-todo|--show-current-patch)
 248                test $total_argc -eq 2 || usage
 249                action=${1##--}
 250                ;;
 251        --onto=*)
 252                onto="${1#--onto=}"
 253                ;;
 254        --exec=*)
 255                cmd="${cmd}exec ${1#--exec=}${LF}"
 256                test -z "$interactive_rebase" && interactive_rebase=implied
 257                ;;
 258        --interactive)
 259                interactive_rebase=explicit
 260                ;;
 261        --keep-empty)
 262                keep_empty=yes
 263                ;;
 264        --allow-empty-message)
 265                allow_empty_message=--allow-empty-message
 266                ;;
 267        --no-keep-empty)
 268                keep_empty=
 269                ;;
 270        --rebase-merges)
 271                rebase_merges=t
 272                test -z "$interactive_rebase" && interactive_rebase=implied
 273                ;;
 274        --rebase-merges=*)
 275                rebase_merges=t
 276                case "${1#*=}" in
 277                rebase-cousins) rebase_cousins=t;;
 278                no-rebase-cousins) rebase_cousins=;;
 279                *) die "Unknown mode: $1";;
 280                esac
 281                test -z "$interactive_rebase" && interactive_rebase=implied
 282                ;;
 283        --preserve-merges)
 284                preserve_merges=t
 285                test -z "$interactive_rebase" && interactive_rebase=implied
 286                ;;
 287        --autosquash)
 288                autosquash=t
 289                ;;
 290        --no-autosquash)
 291                autosquash=
 292                ;;
 293        --fork-point)
 294                fork_point=t
 295                ;;
 296        --no-fork-point)
 297                fork_point=
 298                ;;
 299        --merge)
 300                do_merge=t
 301                ;;
 302        --strategy-option=*)
 303                strategy_opts="$strategy_opts $(git rev-parse --sq-quote "--${1#--strategy-option=}" | sed -e s/^.//)"
 304                do_merge=t
 305                test -z "$strategy" && strategy=recursive
 306                ;;
 307        --strategy=*)
 308                strategy="${1#--strategy=}"
 309                do_merge=t
 310                ;;
 311        --no-stat)
 312                diffstat=
 313                ;;
 314        --stat)
 315                diffstat=t
 316                ;;
 317        --autostash)
 318                autostash=true
 319                ;;
 320        --no-autostash)
 321                autostash=false
 322                ;;
 323        --verbose)
 324                verbose=t
 325                diffstat=t
 326                GIT_QUIET=
 327                ;;
 328        --quiet)
 329                GIT_QUIET=t
 330                git_am_opt="$git_am_opt -q"
 331                verbose=
 332                diffstat=
 333                ;;
 334        --whitespace=*)
 335                git_am_opt="$git_am_opt --whitespace=${1#--whitespace=}"
 336                case "${1#--whitespace=}" in
 337                fix|strip)
 338                        force_rebase=t
 339                        ;;
 340                warn|nowarn|error|error-all)
 341                        ;; # okay, known whitespace option
 342                *)
 343                        die "fatal: Invalid whitespace option: '${1#*=}'"
 344                        ;;
 345                esac
 346                ;;
 347        --ignore-whitespace)
 348                git_am_opt="$git_am_opt $1"
 349                ;;
 350        --signoff)
 351                signoff=--signoff
 352                ;;
 353        --no-signoff)
 354                signoff=
 355                ;;
 356        --committer-date-is-author-date|--ignore-date)
 357                git_am_opt="$git_am_opt $1"
 358                force_rebase=t
 359                ;;
 360        -C*[!0-9]*)
 361                die "fatal: switch \`C' expects a numerical value"
 362                ;;
 363        -C*)
 364                git_am_opt="$git_am_opt $1"
 365                ;;
 366        --root)
 367                rebase_root=t
 368                ;;
 369        --force-rebase|--no-ff)
 370                force_rebase=t
 371                ;;
 372        --rerere-autoupdate|--no-rerere-autoupdate)
 373                allow_rerere_autoupdate="$1"
 374                ;;
 375        --gpg-sign)
 376                gpg_sign_opt=-S
 377                ;;
 378        --gpg-sign=*)
 379                gpg_sign_opt="-S${1#--gpg-sign=}"
 380                ;;
 381        --)
 382                shift
 383                break
 384                ;;
 385        *)
 386                usage
 387                ;;
 388        esac
 389        shift
 390done
 391test $# -gt 2 && usage
 392
 393if test -n "$action"
 394then
 395        test -z "$in_progress" && die "$(gettext "No rebase in progress?")"
 396        # Only interactive rebase uses detailed reflog messages
 397        if test -n "$interactive_rebase" && test "$GIT_REFLOG_ACTION" = rebase
 398        then
 399                GIT_REFLOG_ACTION="rebase -i ($action)"
 400                export GIT_REFLOG_ACTION
 401        fi
 402fi
 403
 404if test "$action" = "edit-todo" && test -z "$interactive_rebase"
 405then
 406        die "$(gettext "The --edit-todo action can only be used during interactive rebase.")"
 407fi
 408
 409case "$action" in
 410continue)
 411        # Sanity check
 412        git rev-parse --verify HEAD >/dev/null ||
 413                die "$(gettext "Cannot read HEAD")"
 414        git update-index --ignore-submodules --refresh &&
 415        git diff-files --quiet --ignore-submodules || {
 416                echo "$(gettext "You must edit all merge conflicts and then
 417mark them as resolved using git add")"
 418                exit 1
 419        }
 420        read_basic_state
 421        run_specific_rebase
 422        ;;
 423skip)
 424        output git reset --hard HEAD || exit $?
 425        read_basic_state
 426        run_specific_rebase
 427        ;;
 428abort)
 429        git rerere clear
 430        read_basic_state
 431        case "$head_name" in
 432        refs/*)
 433                git symbolic-ref -m "rebase: aborting" HEAD $head_name ||
 434                die "$(eval_gettext "Could not move back to \$head_name")"
 435                ;;
 436        esac
 437        output git reset --hard $orig_head
 438        finish_rebase
 439        exit
 440        ;;
 441quit)
 442        exec rm -rf "$state_dir"
 443        ;;
 444edit-todo)
 445        run_specific_rebase
 446        ;;
 447show-current-patch)
 448        run_specific_rebase
 449        die "BUG: run_specific_rebase is not supposed to return here"
 450        ;;
 451esac
 452
 453# Make sure no rebase is in progress
 454if test -n "$in_progress"
 455then
 456        state_dir_base=${state_dir##*/}
 457        cmd_live_rebase="git rebase (--continue | --abort | --skip)"
 458        cmd_clear_stale_rebase="rm -fr \"$state_dir\""
 459        die "
 460$(eval_gettext 'It seems that there is already a $state_dir_base directory, and
 461I wonder if you are in the middle of another rebase.  If that is the
 462case, please try
 463        $cmd_live_rebase
 464If that is not the case, please
 465        $cmd_clear_stale_rebase
 466and run me again.  I am stopping in case you still have something
 467valuable there.')"
 468fi
 469
 470if test -n "$rebase_root" && test -z "$onto"
 471then
 472        test -z "$interactive_rebase" && interactive_rebase=implied
 473fi
 474
 475if test -n "$keep_empty"
 476then
 477        test -z "$interactive_rebase" && interactive_rebase=implied
 478fi
 479
 480if test -n "$interactive_rebase"
 481then
 482        if test -z "$preserve_merges"
 483        then
 484                type=interactive
 485        else
 486                type=preserve-merges
 487        fi
 488
 489        state_dir="$merge_dir"
 490elif test -n "$do_merge"
 491then
 492        type=merge
 493        state_dir="$merge_dir"
 494else
 495        type=am
 496        state_dir="$apply_dir"
 497fi
 498
 499if test -t 2 && test -z "$GIT_QUIET"
 500then
 501        git_format_patch_opt="$git_format_patch_opt --progress"
 502fi
 503
 504if test -n "$git_am_opt"; then
 505        incompatible_opts=$(echo " $git_am_opt " | \
 506                            sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
 507        if test -n "$interactive_rebase"
 508        then
 509                if test -n "$incompatible_opts"
 510                then
 511                        die "$(gettext "error: cannot combine interactive options (--interactive, --exec, --rebase-merges, --preserve-merges, --keep-empty, --root + --onto) with am options ($incompatible_opts)")"
 512                fi
 513        fi
 514        if test -n "$do_merge"; then
 515                if test -n "$incompatible_opts"
 516                then
 517                        die "$(gettext "error: cannot combine merge options (--merge, --strategy, --strategy-option) with am options ($incompatible_opts)")"
 518                fi
 519        fi
 520fi
 521
 522if test -n "$signoff"
 523then
 524        test -n "$preserve_merges" &&
 525                die "$(gettext "error: cannot combine '--signoff' with '--preserve-merges'")"
 526        git_am_opt="$git_am_opt $signoff"
 527        force_rebase=t
 528fi
 529
 530if test -n "$preserve_merges"
 531then
 532        # Note: incompatibility with --signoff handled in signoff block above
 533        # Note: incompatibility with --interactive is just a strong warning;
 534        #       git-rebase.txt caveats with "unless you know what you are doing"
 535        test -n "$rebase_merges" &&
 536                die "$(gettext "error: cannot combine '--preserve-merges' with '--rebase-merges'")"
 537fi
 538
 539if test -n "$rebase_merges"
 540then
 541        test -n "$strategy_opts" &&
 542                die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy-option'")"
 543        test -n "$strategy" &&
 544                die "$(gettext "error: cannot combine '--rebase-merges' with '--strategy'")"
 545fi
 546
 547if test -z "$rebase_root"
 548then
 549        case "$#" in
 550        0)
 551                if ! upstream_name=$(git rev-parse --symbolic-full-name \
 552                        --verify -q @{upstream} 2>/dev/null)
 553                then
 554                        . git-parse-remote
 555                        error_on_missing_default_upstream "rebase" "rebase" \
 556                                "against" "git rebase $(gettext '<branch>')"
 557                fi
 558
 559                test "$fork_point" = auto && fork_point=t
 560                ;;
 561        *)      upstream_name="$1"
 562                if test "$upstream_name" = "-"
 563                then
 564                        upstream_name="@{-1}"
 565                fi
 566                shift
 567                ;;
 568        esac
 569        upstream=$(peel_committish "${upstream_name}") ||
 570        die "$(eval_gettext "invalid upstream '\$upstream_name'")"
 571        upstream_arg="$upstream_name"
 572else
 573        if test -z "$onto"
 574        then
 575                empty_tree=$(git hash-object -t tree /dev/null)
 576                onto=$(git commit-tree $empty_tree </dev/null)
 577                squash_onto="$onto"
 578        fi
 579        unset upstream_name
 580        unset upstream
 581        test $# -gt 1 && usage
 582        upstream_arg=--root
 583fi
 584
 585# Make sure the branch to rebase onto is valid.
 586onto_name=${onto-"$upstream_name"}
 587case "$onto_name" in
 588*...*)
 589        if      left=${onto_name%...*} right=${onto_name#*...} &&
 590                onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
 591        then
 592                case "$onto" in
 593                ?*"$LF"?*)
 594                        die "$(eval_gettext "\$onto_name: there are more than one merge bases")"
 595                        ;;
 596                '')
 597                        die "$(eval_gettext "\$onto_name: there is no merge base")"
 598                        ;;
 599                esac
 600        else
 601                die "$(eval_gettext "\$onto_name: there is no merge base")"
 602        fi
 603        ;;
 604*)
 605        onto=$(peel_committish "$onto_name") ||
 606        die "$(eval_gettext "Does not point to a valid commit: \$onto_name")"
 607        ;;
 608esac
 609
 610# If the branch to rebase is given, that is the branch we will rebase
 611# $branch_name -- branch/commit being rebased, or HEAD (already detached)
 612# $orig_head -- commit object name of tip of the branch before rebasing
 613# $head_name -- refs/heads/<that-branch> or "detached HEAD"
 614switch_to=
 615case "$#" in
 6161)
 617        # Is it "rebase other $branchname" or "rebase other $commit"?
 618        branch_name="$1"
 619        switch_to="$1"
 620
 621        # Is it a local branch?
 622        if git show-ref --verify --quiet -- "refs/heads/$branch_name" &&
 623           orig_head=$(git rev-parse -q --verify "refs/heads/$branch_name")
 624        then
 625                head_name="refs/heads/$branch_name"
 626        # If not is it a valid ref (branch or commit)?
 627        elif orig_head=$(git rev-parse -q --verify "$branch_name")
 628        then
 629                head_name="detached HEAD"
 630
 631        else
 632                die "$(eval_gettext "fatal: no such branch/commit '\$branch_name'")"
 633        fi
 634        ;;
 6350)
 636        # Do not need to switch branches, we are already on it.
 637        if branch_name=$(git symbolic-ref -q HEAD)
 638        then
 639                head_name=$branch_name
 640                branch_name=$(expr "z$branch_name" : 'zrefs/heads/\(.*\)')
 641        else
 642                head_name="detached HEAD"
 643                branch_name=HEAD
 644        fi
 645        orig_head=$(git rev-parse --verify HEAD) || exit
 646        ;;
 647*)
 648        die "BUG: unexpected number of arguments left to parse"
 649        ;;
 650esac
 651
 652if test "$fork_point" = t
 653then
 654        new_upstream=$(git merge-base --fork-point "$upstream_name" \
 655                        "${switch_to:-HEAD}")
 656        if test -n "$new_upstream"
 657        then
 658                restrict_revision=$new_upstream
 659        fi
 660fi
 661
 662if test "$autostash" = true && ! (require_clean_work_tree) 2>/dev/null
 663then
 664        stash_sha1=$(git stash create "autostash") ||
 665        die "$(gettext 'Cannot autostash')"
 666
 667        mkdir -p "$state_dir" &&
 668        echo $stash_sha1 >"$state_dir/autostash" &&
 669        stash_abbrev=$(git rev-parse --short $stash_sha1) &&
 670        echo "$(eval_gettext 'Created autostash: $stash_abbrev')" &&
 671        git reset --hard
 672fi
 673
 674require_clean_work_tree "rebase" "$(gettext "Please commit or stash them.")"
 675
 676# Now we are rebasing commits $upstream..$orig_head (or with --root,
 677# everything leading up to $orig_head) on top of $onto
 678
 679# Check if we are already based on $onto with linear history,
 680# but this should be done only when upstream and onto are the same
 681# and if this is not an interactive rebase.
 682mb=$(git merge-base "$onto" "$orig_head")
 683if test -z "$interactive_rebase" && test "$upstream" = "$onto" &&
 684        test "$mb" = "$onto" && test -z "$restrict_revision" &&
 685        # linear history?
 686        ! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
 687then
 688        if test -z "$force_rebase"
 689        then
 690                # Lazily switch to the target branch if needed...
 691                test -z "$switch_to" ||
 692                GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $switch_to" \
 693                        git checkout -q "$switch_to" --
 694                if test "$branch_name" = "HEAD" &&
 695                         ! git symbolic-ref -q HEAD
 696                then
 697                        say "$(eval_gettext "HEAD is up to date.")"
 698                else
 699                        say "$(eval_gettext "Current branch \$branch_name is up to date.")"
 700                fi
 701                finish_rebase
 702                exit 0
 703        else
 704                if test "$branch_name" = "HEAD" &&
 705                         ! git symbolic-ref -q HEAD
 706                then
 707                        say "$(eval_gettext "HEAD is up to date, rebase forced.")"
 708                else
 709                        say "$(eval_gettext "Current branch \$branch_name is up to date, rebase forced.")"
 710                fi
 711        fi
 712fi
 713
 714# If a hook exists, give it a chance to interrupt
 715run_pre_rebase_hook "$upstream_arg" "$@"
 716
 717if test -n "$diffstat"
 718then
 719        if test -n "$verbose"
 720        then
 721                if test -z "$mb"
 722                then
 723                        echo "$(eval_gettext "Changes to \$onto:")"
 724                else
 725                        echo "$(eval_gettext "Changes from \$mb to \$onto:")"
 726                fi
 727        fi
 728        mb_tree="${mb:-$(git hash-object -t tree /dev/null)}"
 729        # We want color (if set), but no pager
 730        GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
 731fi
 732
 733test -n "$interactive_rebase" && run_specific_rebase
 734
 735# Detach HEAD and reset the tree
 736say "$(gettext "First, rewinding head to replay your work on top of it...")"
 737
 738GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
 739        git checkout -q "$onto^0" || die "could not detach HEAD"
 740git update-ref ORIG_HEAD $orig_head
 741
 742# If the $onto is a proper descendant of the tip of the branch, then
 743# we just fast-forwarded.
 744if test "$mb" = "$orig_head"
 745then
 746        say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
 747        move_to_original_branch
 748        finish_rebase
 749        exit 0
 750fi
 751
 752if test -n "$rebase_root"
 753then
 754        revisions="$onto..$orig_head"
 755else
 756        revisions="${restrict_revision-$upstream}..$orig_head"
 757fi
 758
 759run_specific_rebase