Andrew's git / gitweb.git / git-legacy-rebase.sh
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git-legacy-rebase.shon commit restore: fix typo in docs (21416f0)
   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
  51reschedule-failed-exec automatically reschedule failed exec commands
  52"
  53. git-sh-setup
  54set_reflog_action rebase
  55require_work_tree_exists
  56cd_to_toplevel
  57
  58LF='
  59'
  60ok_to_skip_pre_rebase=
  61
  62squash_onto=
  63unset onto
  64unset restrict_revision
  65cmd=
  66strategy=
  67strategy_opts=
  68do_merge=
  69merge_dir="$GIT_DIR"/rebase-merge
  70apply_dir="$GIT_DIR"/rebase-apply
  71verbose=
  72diffstat=
  73test "$(git config --bool rebase.stat)" = true && diffstat=t
  74autostash="$(git config --bool rebase.autostash || echo false)"
  75fork_point=auto
  76git_am_opt=
  77git_format_patch_opt=
  78rebase_root=
  79force_rebase=
  80allow_rerere_autoupdate=
  81# Non-empty if a rebase was in progress when 'git rebase' was invoked
  82in_progress=
  83# One of {am, merge, interactive}
  84type=
  85# One of {"$GIT_DIR"/rebase-apply, "$GIT_DIR"/rebase-merge}
  86state_dir=
  87# One of {'', continue, skip, abort}, as parsed from command line
  88action=
  89rebase_merges=
  90rebase_cousins=
  91preserve_merges=
  92autosquash=
  93keep_empty=
  94allow_empty_message=--allow-empty-message
  95signoff=
  96reschedule_failed_exec=
  97test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
  98case "$(git config --bool commit.gpgsign)" in
  99true)   gpg_sign_opt=-S ;;
 100*)      gpg_sign_opt= ;;
 101esac
 102test "$(git config --bool rebase.reschedulefailedexec)" = "true" &&
 103reschedule_failed_exec=--reschedule-failed-exec
 104. git-rebase--common
 105
 106read_basic_state () {
 107        test -f "$state_dir/head-name" &&
 108        test -f "$state_dir/onto" &&
 109        head_name=$(cat "$state_dir"/head-name) &&
 110        onto=$(cat "$state_dir"/onto) &&
 111        # We always write to orig-head, but interactive rebase used to write to
 112        # head. Fall back to reading from head to cover for the case that the
 113        # user upgraded git with an ongoing interactive rebase.
 114        if test -f "$state_dir"/orig-head
 115        then
 116                orig_head=$(cat "$state_dir"/orig-head)
 117        else
 118                orig_head=$(cat "$state_dir"/head)
 119        fi &&
 120        test -f "$state_dir"/quiet && GIT_QUIET=t
 121        test -f "$state_dir"/verbose && verbose=t
 122        test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
 123        test -f "$state_dir"/strategy_opts &&
 124                strategy_opts="$(cat "$state_dir"/strategy_opts)"
 125        test -f "$state_dir"/allow_rerere_autoupdate &&
 126                allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
 127        test -f "$state_dir"/gpg_sign_opt &&
 128                gpg_sign_opt="$(cat "$state_dir"/gpg_sign_opt)"
 129        test -f "$state_dir"/signoff && {
 130                signoff="$(cat "$state_dir"/signoff)"
 131                force_rebase=t
 132        }
 133        test -f "$state_dir"/reschedule-failed-exec &&
 134                reschedule_failed_exec=t
 135}
 136
 137finish_rebase () {
 138        rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 139        apply_autostash &&
 140        { git gc --auto || true; } &&
 141        rm -rf "$state_dir"
 142}
 143
 144run_interactive () {
 145        GIT_CHERRY_PICK_HELP="$resolvemsg"
 146        export GIT_CHERRY_PICK_HELP
 147
 148        test -n "$keep_empty" && keep_empty="--keep-empty"
 149        test -n "$rebase_merges" && rebase_merges="--rebase-merges"
 150        test -n "$rebase_cousins" && rebase_cousins="--rebase-cousins"
 151        test -n "$autosquash" && autosquash="--autosquash"
 152        test -n "$verbose" && verbose="--verbose"
 153        test -n "$force_rebase" && force_rebase="--no-ff"
 154        test -n "$restrict_revision" && \
 155                restrict_revision="--restrict-revision=^$restrict_revision"
 156        test -n "$upstream" && upstream="--upstream=$upstream"
 157        test -n "$onto" && onto="--onto=$onto"
 158        test -n "$squash_onto" && squash_onto="--squash-onto=$squash_onto"
 159        test -n "$onto_name" && onto_name="--onto-name=$onto_name"
 160        test -n "$head_name" && head_name="--head-name=$head_name"
 161        test -n "$strategy" && strategy="--strategy=$strategy"
 162        test -n "$strategy_opts" && strategy_opts="--strategy-opts=$strategy_opts"
 163        test -n "$switch_to" && switch_to="--switch-to=$switch_to"
 164        test -n "$cmd" && cmd="--cmd=$cmd"
 165        test -n "$action" && action="--$action"
 166
 167        exec git rebase--interactive "$action" "$keep_empty" "$rebase_merges" "$rebase_cousins" \
 168                "$upstream" "$onto" "$squash_onto" "$restrict_revision" \
 169                "$allow_empty_message" "$autosquash" "$verbose" \
 170                "$force_rebase" "$onto_name" "$head_name" "$strategy" \
 171                "$strategy_opts" "$cmd" "$switch_to" \
 172                "$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff" \
 173                "$reschedule_failed_exec"
 174}
 175
 176run_specific_rebase () {
 177        if [ "$interactive_rebase" = implied ]; then
 178                GIT_SEQUENCE_EDITOR=:
 179                export GIT_SEQUENCE_EDITOR
 180                autosquash=
 181        fi
 182
 183        if test -n "$interactive_rebase" -a -z "$preserve_merges"
 184        then
 185                run_interactive
 186        else
 187                . git-rebase--$type
 188
 189                if test -z "$preserve_merges"
 190                then
 191                        git_rebase__$type
 192                else
 193                        git_rebase__preserve_merges
 194                fi
 195        fi
 196
 197        ret=$?
 198        if test $ret -eq 0
 199        then
 200                finish_rebase
 201        elif test $ret -eq 2 # special exit status for rebase -p
 202        then
 203                apply_autostash &&
 204                rm -rf "$state_dir" &&
 205                die "Nothing to do"
 206        fi
 207        exit $ret
 208}
 209
 210run_pre_rebase_hook () {
 211        if test -z "$ok_to_skip_pre_rebase" &&
 212           test -x "$(git rev-parse --git-path hooks/pre-rebase)"
 213        then
 214                "$(git rev-parse --git-path hooks/pre-rebase)" ${1+"$@"} ||
 215                die "$(gettext "The pre-rebase hook refused to rebase.")"
 216        fi
 217}
 218
 219test -f "$apply_dir"/applying &&
 220        die "$(gettext "It looks like 'git am' is in progress. Cannot rebase.")"
 221
 222if test -d "$apply_dir"
 223then
 224        type=am
 225        state_dir="$apply_dir"
 226elif test -d "$merge_dir"
 227then
 228        type=interactive
 229        if test -d "$merge_dir"/rewritten
 230        then
 231                type=preserve-merges
 232                interactive_rebase=explicit
 233                preserve_merges=t
 234        elif test -f "$merge_dir"/interactive
 235        then
 236                interactive_rebase=explicit
 237        fi
 238        state_dir="$merge_dir"
 239fi
 240test -n "$type" && in_progress=t
 241
 242total_argc=$#
 243while test $# != 0
 244do
 245        case "$1" in
 246        --no-verify)
 247                ok_to_skip_pre_rebase=yes
 248                ;;
 249        --verify)
 250                ok_to_skip_pre_rebase=
 251                ;;
 252        --continue|--skip|--abort|--quit|--edit-todo|--show-current-patch)
 253                test $total_argc -eq 2 || usage
 254                action=${1##--}
 255                ;;
 256        --onto=*)
 257                onto="${1#--onto=}"
 258                ;;
 259        --exec=*)
 260                cmd="${cmd}exec ${1#--exec=}${LF}"
 261                test -z "$interactive_rebase" && interactive_rebase=implied
 262                ;;
 263        --interactive)
 264                interactive_rebase=explicit
 265                ;;
 266        --keep-empty)
 267                keep_empty=yes
 268                ;;
 269        --allow-empty-message)
 270                allow_empty_message=--allow-empty-message
 271                ;;
 272        --no-keep-empty)
 273                keep_empty=
 274                ;;
 275        --rebase-merges)
 276                rebase_merges=t
 277                test -z "$interactive_rebase" && interactive_rebase=implied
 278                ;;
 279        --rebase-merges=*)
 280                rebase_merges=t
 281                case "${1#*=}" in
 282                rebase-cousins) rebase_cousins=t;;
 283                no-rebase-cousins) rebase_cousins=;;
 284                *) die "Unknown mode: $1";;
 285                esac
 286                test -z "$interactive_rebase" && interactive_rebase=implied
 287                ;;
 288        --preserve-merges)
 289                preserve_merges=t
 290                test -z "$interactive_rebase" && interactive_rebase=implied
 291                ;;
 292        --autosquash)
 293                autosquash=t
 294                ;;
 295        --no-autosquash)
 296                autosquash=
 297                ;;
 298        --fork-point)
 299                fork_point=t
 300                ;;
 301        --no-fork-point)
 302                fork_point=
 303                ;;
 304        --merge)
 305                do_merge=t
 306                ;;
 307        --strategy-option=*)
 308                strategy_opts="$strategy_opts $(git rev-parse --sq-quote "--${1#--strategy-option=}" | sed -e s/^.//)"
 309                do_merge=t
 310                test -z "$strategy" && strategy=recursive
 311                ;;
 312        --strategy=*)
 313                strategy="${1#--strategy=}"
 314                do_merge=t
 315                ;;
 316        --no-stat)
 317                diffstat=
 318                ;;
 319        --stat)
 320                diffstat=t
 321                ;;
 322        --autostash)
 323                autostash=true
 324                ;;
 325        --no-autostash)
 326                autostash=false
 327                ;;
 328        --verbose)
 329                verbose=t
 330                diffstat=t
 331                GIT_QUIET=
 332                ;;
 333        --quiet)
 334                GIT_QUIET=t
 335                git_am_opt="$git_am_opt -q"
 336                verbose=
 337                diffstat=
 338                ;;
 339        --whitespace=*)
 340                git_am_opt="$git_am_opt --whitespace=${1#--whitespace=}"
 341                case "${1#--whitespace=}" in
 342                fix|strip)
 343                        force_rebase=t
 344                        ;;
 345                warn|nowarn|error|error-all)
 346                        ;; # okay, known whitespace option
 347                *)
 348                        die "fatal: Invalid whitespace option: '${1#*=}'"
 349                        ;;
 350                esac
 351                ;;
 352        --ignore-whitespace)
 353                git_am_opt="$git_am_opt $1"
 354                ;;
 355        --signoff)
 356                signoff=--signoff
 357                ;;
 358        --no-signoff)
 359                signoff=
 360                ;;
 361        --committer-date-is-author-date|--ignore-date)
 362                git_am_opt="$git_am_opt $1"
 363                force_rebase=t
 364                ;;
 365        -C*[!0-9]*)
 366                die "fatal: switch \`C' expects a numerical value"
 367                ;;
 368        -C*)
 369                git_am_opt="$git_am_opt $1"
 370                ;;
 371        --root)
 372                rebase_root=t
 373                ;;
 374        --force-rebase|--no-ff)
 375                force_rebase=t
 376                ;;
 377        --rerere-autoupdate|--no-rerere-autoupdate)
 378                allow_rerere_autoupdate="$1"
 379                ;;
 380        --gpg-sign)
 381                gpg_sign_opt=-S
 382                ;;
 383        --gpg-sign=*)
 384                gpg_sign_opt="-S${1#--gpg-sign=}"
 385                ;;
 386        --reschedule-failed-exec)
 387                reschedule_failed_exec=--reschedule-failed-exec
 388                ;;
 389        --no-reschedule-failed-exec)
 390                reschedule_failed_exec=
 391                ;;
 392        --)
 393                shift
 394                break
 395                ;;
 396        *)
 397                usage
 398                ;;
 399        esac
 400        shift
 401done
 402test $# -gt 2 && usage
 403
 404if test -n "$action"
 405then
 406        test -z "$in_progress" && die "$(gettext "No rebase in progress?")"
 407        # Only interactive rebase uses detailed reflog messages
 408        if test -n "$interactive_rebase" && test "$GIT_REFLOG_ACTION" = rebase
 409        then
 410                GIT_REFLOG_ACTION="rebase -i ($action)"
 411                export GIT_REFLOG_ACTION
 412        fi
 413fi
 414
 415if test "$action" = "edit-todo" && test -z "$interactive_rebase"
 416then
 417        die "$(gettext "The --edit-todo action can only be used during interactive rebase.")"
 418fi
 419
 420case "$action" in
 421continue)
 422        # Sanity check
 423        git rev-parse --verify HEAD >/dev/null ||
 424                die "$(gettext "Cannot read HEAD")"
 425        git update-index --ignore-submodules --refresh &&
 426        git diff-files --quiet --ignore-submodules || {
 427                echo "$(gettext "You must edit all merge conflicts and then
 428mark them as resolved using git add")"
 429                exit 1
 430        }
 431        read_basic_state
 432        run_specific_rebase
 433        ;;
 434skip)
 435        output git reset --hard HEAD || exit $?
 436        read_basic_state
 437        run_specific_rebase
 438        ;;
 439abort)
 440        git rerere clear
 441        read_basic_state
 442        case "$head_name" in
 443        refs/*)
 444                git symbolic-ref -m "rebase: aborting" HEAD $head_name ||
 445                die "$(eval_gettext "Could not move back to \$head_name")"
 446                ;;
 447        esac
 448        output git reset --hard $orig_head
 449        finish_rebase
 450        exit
 451        ;;
 452quit)
 453        exec rm -rf "$state_dir"
 454        ;;
 455edit-todo)
 456        run_specific_rebase
 457        ;;
 458show-current-patch)
 459        run_specific_rebase
 460        die "BUG: run_specific_rebase is not supposed to return here"
 461        ;;
 462esac
 463
 464# Make sure no rebase is in progress
 465if test -n "$in_progress"
 466then
 467        state_dir_base=${state_dir##*/}
 468        cmd_live_rebase="git rebase (--continue | --abort | --skip)"
 469        cmd_clear_stale_rebase="rm -fr \"$state_dir\""
 470        die "
 471$(eval_gettext 'It seems that there is already a $state_dir_base directory, and
 472I wonder if you are in the middle of another rebase.  If that is the
 473case, please try
 474        $cmd_live_rebase
 475If that is not the case, please
 476        $cmd_clear_stale_rebase
 477and run me again.  I am stopping in case you still have something
 478valuable there.')"
 479fi
 480
 481if test -n "$rebase_root" && test -z "$onto"
 482then
 483        test -z "$interactive_rebase" && interactive_rebase=implied
 484fi
 485
 486if test -n "$keep_empty"
 487then
 488        test -z "$interactive_rebase" && interactive_rebase=implied
 489fi
 490
 491actually_interactive=
 492if test -n "$interactive_rebase"
 493then
 494        if test -z "$preserve_merges"
 495        then
 496                type=interactive
 497        else
 498                type=preserve-merges
 499        fi
 500        actually_interactive=t
 501        state_dir="$merge_dir"
 502elif test -n "$do_merge"
 503then
 504        interactive_rebase=implied
 505        type=interactive
 506        state_dir="$merge_dir"
 507else
 508        type=am
 509        state_dir="$apply_dir"
 510fi
 511
 512if test -t 2 && test -z "$GIT_QUIET"
 513then
 514        git_format_patch_opt="$git_format_patch_opt --progress"
 515fi
 516
 517incompatible_opts=$(echo " $git_am_opt " | \
 518                    sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
 519if test -n "$incompatible_opts"
 520then
 521        if test -n "$actually_interactive" || test "$do_merge"
 522        then
 523                die "$(gettext "fatal: cannot combine am options with either interactive or merge options")"
 524        fi
 525fi
 526
 527if test -n "$signoff"
 528then
 529        test -n "$preserve_merges" &&
 530                die "$(gettext "fatal: cannot combine '--signoff' with '--preserve-merges'")"
 531        git_am_opt="$git_am_opt $signoff"
 532        force_rebase=t
 533fi
 534
 535if test -n "$preserve_merges"
 536then
 537        # Note: incompatibility with --signoff handled in signoff block above
 538        # Note: incompatibility with --interactive is just a strong warning;
 539        #       git-rebase.txt caveats with "unless you know what you are doing"
 540        test -n "$rebase_merges" &&
 541                die "$(gettext "fatal: cannot combine '--preserve-merges' with '--rebase-merges'")"
 542
 543        test -n "$reschedule_failed_exec" &&
 544                die "$(gettext "error: cannot combine '--preserve-merges' with '--reschedule-failed-exec'")"
 545fi
 546
 547if test -n "$rebase_merges"
 548then
 549        test -n "$strategy_opts" &&
 550                die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy-option'")"
 551        test -n "$strategy" &&
 552                die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy'")"
 553fi
 554
 555if test -z "$rebase_root"
 556then
 557        case "$#" in
 558        0)
 559                if ! upstream_name=$(git rev-parse --symbolic-full-name \
 560                        --verify -q @{upstream} 2>/dev/null)
 561                then
 562                        . git-parse-remote
 563                        error_on_missing_default_upstream "rebase" "rebase" \
 564                                "against" "git rebase $(gettext '<branch>')"
 565                fi
 566
 567                test "$fork_point" = auto && fork_point=t
 568                ;;
 569        *)      upstream_name="$1"
 570                if test "$upstream_name" = "-"
 571                then
 572                        upstream_name="@{-1}"
 573                fi
 574                shift
 575                ;;
 576        esac
 577        upstream=$(peel_committish "${upstream_name}") ||
 578        die "$(eval_gettext "invalid upstream '\$upstream_name'")"
 579        upstream_arg="$upstream_name"
 580else
 581        if test -z "$onto"
 582        then
 583                empty_tree=$(git hash-object -t tree /dev/null)
 584                onto=$(git commit-tree $empty_tree </dev/null)
 585                squash_onto="$onto"
 586        fi
 587        unset upstream_name
 588        unset upstream
 589        test $# -gt 1 && usage
 590        upstream_arg=--root
 591fi
 592
 593# Make sure the branch to rebase onto is valid.
 594onto_name=${onto-"$upstream_name"}
 595case "$onto_name" in
 596*...*)
 597        if      left=${onto_name%...*} right=${onto_name#*...} &&
 598                onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
 599        then
 600                case "$onto" in
 601                ?*"$LF"?*)
 602                        die "$(eval_gettext "\$onto_name: there are more than one merge bases")"
 603                        ;;
 604                '')
 605                        die "$(eval_gettext "\$onto_name: there is no merge base")"
 606                        ;;
 607                esac
 608        else
 609                die "$(eval_gettext "\$onto_name: there is no merge base")"
 610        fi
 611        ;;
 612*)
 613        onto=$(peel_committish "$onto_name") ||
 614        die "$(eval_gettext "Does not point to a valid commit: \$onto_name")"
 615        ;;
 616esac
 617
 618# If the branch to rebase is given, that is the branch we will rebase
 619# $branch_name -- branch/commit being rebased, or HEAD (already detached)
 620# $orig_head -- commit object name of tip of the branch before rebasing
 621# $head_name -- refs/heads/<that-branch> or "detached HEAD"
 622switch_to=
 623case "$#" in
 6241)
 625        # Is it "rebase other $branchname" or "rebase other $commit"?
 626        branch_name="$1"
 627        switch_to="$1"
 628
 629        # Is it a local branch?
 630        if git show-ref --verify --quiet -- "refs/heads/$branch_name" &&
 631           orig_head=$(git rev-parse -q --verify "refs/heads/$branch_name")
 632        then
 633                head_name="refs/heads/$branch_name"
 634        # If not is it a valid ref (branch or commit)?
 635        elif orig_head=$(git rev-parse -q --verify "$branch_name")
 636        then
 637                head_name="detached HEAD"
 638
 639        else
 640                die "$(eval_gettext "fatal: no such branch/commit '\$branch_name'")"
 641        fi
 642        ;;
 6430)
 644        # Do not need to switch branches, we are already on it.
 645        if branch_name=$(git symbolic-ref -q HEAD)
 646        then
 647                head_name=$branch_name
 648                branch_name=$(expr "z$branch_name" : 'zrefs/heads/\(.*\)')
 649        else
 650                head_name="detached HEAD"
 651                branch_name=HEAD
 652        fi
 653        orig_head=$(git rev-parse --verify HEAD) || exit
 654        ;;
 655*)
 656        die "BUG: unexpected number of arguments left to parse"
 657        ;;
 658esac
 659
 660if test "$fork_point" = t
 661then
 662        new_upstream=$(git merge-base --fork-point "$upstream_name" \
 663                        "${switch_to:-HEAD}")
 664        if test -n "$new_upstream"
 665        then
 666                restrict_revision=$new_upstream
 667        fi
 668fi
 669
 670if test "$autostash" = true && ! (require_clean_work_tree) 2>/dev/null
 671then
 672        stash_sha1=$(git stash create "autostash") ||
 673        die "$(gettext 'Cannot autostash')"
 674
 675        mkdir -p "$state_dir" &&
 676        echo $stash_sha1 >"$state_dir/autostash" &&
 677        stash_abbrev=$(git rev-parse --short $stash_sha1) &&
 678        echo "$(eval_gettext 'Created autostash: $stash_abbrev')" &&
 679        git reset --hard
 680fi
 681
 682require_clean_work_tree "rebase" "$(gettext "Please commit or stash them.")"
 683
 684# Now we are rebasing commits $upstream..$orig_head (or with --root,
 685# everything leading up to $orig_head) on top of $onto
 686
 687# Check if we are already based on $onto with linear history,
 688# but this should be done only when upstream and onto are the same
 689# and if this is not an interactive rebase.
 690mb=$(git merge-base "$onto" "$orig_head")
 691if test -z "$actually_interactive" && test "$upstream" = "$onto" &&
 692        test "$mb" = "$onto" && test -z "$restrict_revision" &&
 693        # linear history?
 694        ! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
 695then
 696        if test -z "$force_rebase"
 697        then
 698                # Lazily switch to the target branch if needed...
 699                test -z "$switch_to" ||
 700                GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $switch_to" \
 701                        git checkout -q "$switch_to" --
 702                if test "$branch_name" = "HEAD" &&
 703                         ! git symbolic-ref -q HEAD
 704                then
 705                        say "$(eval_gettext "HEAD is up to date.")"
 706                else
 707                        say "$(eval_gettext "Current branch \$branch_name is up to date.")"
 708                fi
 709                finish_rebase
 710                exit 0
 711        else
 712                if test "$branch_name" = "HEAD" &&
 713                         ! git symbolic-ref -q HEAD
 714                then
 715                        say "$(eval_gettext "HEAD is up to date, rebase forced.")"
 716                else
 717                        say "$(eval_gettext "Current branch \$branch_name is up to date, rebase forced.")"
 718                fi
 719        fi
 720fi
 721
 722# If a hook exists, give it a chance to interrupt
 723run_pre_rebase_hook "$upstream_arg" "$@"
 724
 725if test -n "$diffstat"
 726then
 727        if test -n "$verbose"
 728        then
 729                if test -z "$mb"
 730                then
 731                        echo "$(eval_gettext "Changes to \$onto:")"
 732                else
 733                        echo "$(eval_gettext "Changes from \$mb to \$onto:")"
 734                fi
 735        fi
 736        mb_tree="${mb:-$(git hash-object -t tree /dev/null)}"
 737        # We want color (if set), but no pager
 738        GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
 739fi
 740
 741if test -z "$actually_interactive" && test "$mb" = "$orig_head"
 742then
 743        say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
 744        GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
 745                git checkout -q "$onto^0" || die "could not detach HEAD"
 746        # If the $onto is a proper descendant of the tip of the branch, then
 747        # we just fast-forwarded.
 748        git update-ref ORIG_HEAD $orig_head
 749        move_to_original_branch
 750        finish_rebase
 751        exit 0
 752fi
 753
 754test -n "$interactive_rebase" && run_specific_rebase
 755
 756# Detach HEAD and reset the tree
 757say "$(gettext "First, rewinding head to replay your work on top of it...")"
 758
 759GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
 760        git checkout -q "$onto^0" || die "could not detach HEAD"
 761git update-ref ORIG_HEAD $orig_head
 762
 763if test -n "$rebase_root"
 764then
 765        revisions="$onto..$orig_head"
 766else
 767        revisions="${restrict_revision-$upstream}..$orig_head"
 768fi
 769
 770run_specific_rebase