Merge branch 'br/commit-tree-fully-spelled-gpg-sign-option'
[git] / git-legacy-rebase.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Junio C Hamano.
4 #
5
6 SUBDIRECTORY_OK=Yes
7 OPTIONS_KEEPDASHDASH=
8 OPTIONS_STUCKLONG=t
9 OPTIONS_SPEC="\
10 git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] [<upstream>] [<branch>]
11 git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] --root [<branch>]
12 git rebase --continue | --abort | --skip | --edit-todo
13 --
14  Available options are
15 v,verbose!         display a diffstat of what changed upstream
16 q,quiet!           be quiet. implies --no-stat
17 autostash          automatically stash/stash pop before and after
18 fork-point         use 'merge-base --fork-point' to refine upstream
19 onto=!             rebase onto given branch instead of upstream
20 r,rebase-merges?   try to rebase merges instead of skipping them
21 p,preserve-merges! try to recreate merges instead of ignoring them
22 s,strategy=!       use the given merge strategy
23 X,strategy-option=! pass the argument through to the merge strategy
24 no-ff!             cherry-pick all commits, even if unchanged
25 f,force-rebase!    cherry-pick all commits, even if unchanged
26 m,merge!           use merging strategies to rebase
27 i,interactive!     let the user edit the list of commits to rebase
28 x,exec=!           add exec lines after each commit of the editable list
29 y=!                same as --reschedule-failed-exec -x
30 k,keep-empty       preserve empty commits during rebase
31 allow-empty-message allow rebasing commits with empty messages
32 stat!              display a diffstat of what changed upstream
33 n,no-stat!         do not show diffstat of what changed upstream
34 verify             allow pre-rebase hook to run
35 rerere-autoupdate  allow rerere to update index with resolved conflicts
36 root!              rebase all reachable commits up to the root(s)
37 autosquash         move commits that begin with squash!/fixup! under -i
38 signoff            add a Signed-off-by: line to each commit
39 committer-date-is-author-date! passed to 'git am'
40 ignore-date!       passed to 'git am'
41 whitespace=!       passed to 'git apply'
42 ignore-whitespace! passed to 'git apply'
43 C=!                passed to 'git apply'
44 S,gpg-sign?        GPG-sign commits
45  Actions:
46 continue!          continue
47 abort!             abort and check out the original branch
48 skip!              skip current patch and continue
49 edit-todo!         edit the todo list during an interactive rebase
50 quit!              abort but keep HEAD where it is
51 show-current-patch! show the patch file being applied or merged
52 reschedule-failed-exec automatically reschedule failed exec commands
53 "
54 . git-sh-setup
55 set_reflog_action rebase
56 require_work_tree_exists
57 cd_to_toplevel
58
59 LF='
60 '
61 ok_to_skip_pre_rebase=
62
63 squash_onto=
64 unset onto
65 unset restrict_revision
66 cmd=
67 strategy=
68 strategy_opts=
69 do_merge=
70 merge_dir="$GIT_DIR"/rebase-merge
71 apply_dir="$GIT_DIR"/rebase-apply
72 verbose=
73 diffstat=
74 test "$(git config --bool rebase.stat)" = true && diffstat=t
75 autostash="$(git config --bool rebase.autostash || echo false)"
76 fork_point=auto
77 git_am_opt=
78 git_format_patch_opt=
79 rebase_root=
80 force_rebase=
81 allow_rerere_autoupdate=
82 # Non-empty if a rebase was in progress when 'git rebase' was invoked
83 in_progress=
84 # One of {am, merge, interactive}
85 type=
86 # One of {"$GIT_DIR"/rebase-apply, "$GIT_DIR"/rebase-merge}
87 state_dir=
88 # One of {'', continue, skip, abort}, as parsed from command line
89 action=
90 rebase_merges=
91 rebase_cousins=
92 preserve_merges=
93 autosquash=
94 keep_empty=
95 allow_empty_message=--allow-empty-message
96 signoff=
97 reschedule_failed_exec=
98 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
99 case "$(git config --bool commit.gpgsign)" in
100 true)   gpg_sign_opt=-S ;;
101 *)      gpg_sign_opt= ;;
102 esac
103 test "$(git config --bool rebase.reschedulefailedexec)" = "true" &&
104 reschedule_failed_exec=--reschedule-failed-exec
105 . git-rebase--common
106
107 read_basic_state () {
108         test -f "$state_dir/head-name" &&
109         test -f "$state_dir/onto" &&
110         head_name=$(cat "$state_dir"/head-name) &&
111         onto=$(cat "$state_dir"/onto) &&
112         # We always write to orig-head, but interactive rebase used to write to
113         # head. Fall back to reading from head to cover for the case that the
114         # user upgraded git with an ongoing interactive rebase.
115         if test -f "$state_dir"/orig-head
116         then
117                 orig_head=$(cat "$state_dir"/orig-head)
118         else
119                 orig_head=$(cat "$state_dir"/head)
120         fi &&
121         test -f "$state_dir"/quiet && GIT_QUIET=t
122         test -f "$state_dir"/verbose && verbose=t
123         test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
124         test -f "$state_dir"/strategy_opts &&
125                 strategy_opts="$(cat "$state_dir"/strategy_opts)"
126         test -f "$state_dir"/allow_rerere_autoupdate &&
127                 allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
128         test -f "$state_dir"/gpg_sign_opt &&
129                 gpg_sign_opt="$(cat "$state_dir"/gpg_sign_opt)"
130         test -f "$state_dir"/signoff && {
131                 signoff="$(cat "$state_dir"/signoff)"
132                 force_rebase=t
133         }
134         test -f "$state_dir"/reschedule-failed-exec &&
135                 reschedule_failed_exec=t
136 }
137
138 finish_rebase () {
139         rm -f "$(git rev-parse --git-path REBASE_HEAD)"
140         apply_autostash &&
141         { git gc --auto || true; } &&
142         rm -rf "$state_dir"
143 }
144
145 run_interactive () {
146         GIT_CHERRY_PICK_HELP="$resolvemsg"
147         export GIT_CHERRY_PICK_HELP
148
149         test -n "$keep_empty" && keep_empty="--keep-empty"
150         test -n "$rebase_merges" && rebase_merges="--rebase-merges"
151         test -n "$rebase_cousins" && rebase_cousins="--rebase-cousins"
152         test -n "$autosquash" && autosquash="--autosquash"
153         test -n "$verbose" && verbose="--verbose"
154         test -n "$force_rebase" && force_rebase="--no-ff"
155         test -n "$restrict_revision" && \
156                 restrict_revision="--restrict-revision=^$restrict_revision"
157         test -n "$upstream" && upstream="--upstream=$upstream"
158         test -n "$onto" && onto="--onto=$onto"
159         test -n "$squash_onto" && squash_onto="--squash-onto=$squash_onto"
160         test -n "$onto_name" && onto_name="--onto-name=$onto_name"
161         test -n "$head_name" && head_name="--head-name=$head_name"
162         test -n "$strategy" && strategy="--strategy=$strategy"
163         test -n "$strategy_opts" && strategy_opts="--strategy-opts=$strategy_opts"
164         test -n "$switch_to" && switch_to="--switch-to=$switch_to"
165         test -n "$cmd" && cmd="--cmd=$cmd"
166         test -n "$action" && action="--$action"
167
168         exec git rebase--interactive "$action" "$keep_empty" "$rebase_merges" "$rebase_cousins" \
169                 "$upstream" "$onto" "$squash_onto" "$restrict_revision" \
170                 "$allow_empty_message" "$autosquash" "$verbose" \
171                 "$force_rebase" "$onto_name" "$head_name" "$strategy" \
172                 "$strategy_opts" "$cmd" "$switch_to" \
173                 "$allow_rerere_autoupdate" "$gpg_sign_opt" "$signoff" \
174                 "$reschedule_failed_exec"
175 }
176
177 run_specific_rebase () {
178         if [ "$interactive_rebase" = implied ]; then
179                 GIT_SEQUENCE_EDITOR=:
180                 export GIT_SEQUENCE_EDITOR
181                 autosquash=
182         fi
183
184         if test -n "$interactive_rebase" -a -z "$preserve_merges"
185         then
186                 run_interactive
187         else
188                 . git-rebase--$type
189
190                 if test -z "$preserve_merges"
191                 then
192                         git_rebase__$type
193                 else
194                         git_rebase__preserve_merges
195                 fi
196         fi
197
198         ret=$?
199         if test $ret -eq 0
200         then
201                 finish_rebase
202         elif test $ret -eq 2 # special exit status for rebase -p
203         then
204                 apply_autostash &&
205                 rm -rf "$state_dir" &&
206                 die "Nothing to do"
207         fi
208         exit $ret
209 }
210
211 run_pre_rebase_hook () {
212         if test -z "$ok_to_skip_pre_rebase" &&
213            test -x "$(git rev-parse --git-path hooks/pre-rebase)"
214         then
215                 "$(git rev-parse --git-path hooks/pre-rebase)" ${1+"$@"} ||
216                 die "$(gettext "The pre-rebase hook refused to rebase.")"
217         fi
218 }
219
220 test -f "$apply_dir"/applying &&
221         die "$(gettext "It looks like 'git am' is in progress. Cannot rebase.")"
222
223 if test -d "$apply_dir"
224 then
225         type=am
226         state_dir="$apply_dir"
227 elif test -d "$merge_dir"
228 then
229         type=interactive
230         if test -d "$merge_dir"/rewritten
231         then
232                 type=preserve-merges
233                 interactive_rebase=explicit
234                 preserve_merges=t
235         elif test -f "$merge_dir"/interactive
236         then
237                 interactive_rebase=explicit
238         fi
239         state_dir="$merge_dir"
240 fi
241 test -n "$type" && in_progress=t
242
243 total_argc=$#
244 while test $# != 0
245 do
246         case "$1" in
247         --no-verify)
248                 ok_to_skip_pre_rebase=yes
249                 ;;
250         --verify)
251                 ok_to_skip_pre_rebase=
252                 ;;
253         --continue|--skip|--abort|--quit|--edit-todo|--show-current-patch)
254                 test $total_argc -eq 2 || usage
255                 action=${1##--}
256                 ;;
257         --onto=*)
258                 onto="${1#--onto=}"
259                 ;;
260         --exec=*)
261                 cmd="${cmd}exec ${1#--exec=}${LF}"
262                 test -z "$interactive_rebase" && interactive_rebase=implied
263                 ;;
264         -y*)
265                 reschedule_failed_exec=--reschedule-failed-exec
266                 cmd="${cmd}exec ${1#-y}${LF}"
267                 test -z "$interactive_rebase" && interactive_rebase=implied
268                 ;;
269         --interactive)
270                 interactive_rebase=explicit
271                 ;;
272         --keep-empty)
273                 keep_empty=yes
274                 ;;
275         --allow-empty-message)
276                 allow_empty_message=--allow-empty-message
277                 ;;
278         --no-keep-empty)
279                 keep_empty=
280                 ;;
281         --rebase-merges)
282                 rebase_merges=t
283                 test -z "$interactive_rebase" && interactive_rebase=implied
284                 ;;
285         --rebase-merges=*)
286                 rebase_merges=t
287                 case "${1#*=}" in
288                 rebase-cousins) rebase_cousins=t;;
289                 no-rebase-cousins) rebase_cousins=;;
290                 *) die "Unknown mode: $1";;
291                 esac
292                 test -z "$interactive_rebase" && interactive_rebase=implied
293                 ;;
294         --preserve-merges)
295                 preserve_merges=t
296                 test -z "$interactive_rebase" && interactive_rebase=implied
297                 ;;
298         --autosquash)
299                 autosquash=t
300                 ;;
301         --no-autosquash)
302                 autosquash=
303                 ;;
304         --fork-point)
305                 fork_point=t
306                 ;;
307         --no-fork-point)
308                 fork_point=
309                 ;;
310         --merge)
311                 do_merge=t
312                 ;;
313         --strategy-option=*)
314                 strategy_opts="$strategy_opts $(git rev-parse --sq-quote "--${1#--strategy-option=}" | sed -e s/^.//)"
315                 do_merge=t
316                 test -z "$strategy" && strategy=recursive
317                 ;;
318         --strategy=*)
319                 strategy="${1#--strategy=}"
320                 do_merge=t
321                 ;;
322         --no-stat)
323                 diffstat=
324                 ;;
325         --stat)
326                 diffstat=t
327                 ;;
328         --autostash)
329                 autostash=true
330                 ;;
331         --no-autostash)
332                 autostash=false
333                 ;;
334         --verbose)
335                 verbose=t
336                 diffstat=t
337                 GIT_QUIET=
338                 ;;
339         --quiet)
340                 GIT_QUIET=t
341                 git_am_opt="$git_am_opt -q"
342                 verbose=
343                 diffstat=
344                 ;;
345         --whitespace=*)
346                 git_am_opt="$git_am_opt --whitespace=${1#--whitespace=}"
347                 case "${1#--whitespace=}" in
348                 fix|strip)
349                         force_rebase=t
350                         ;;
351                 warn|nowarn|error|error-all)
352                         ;; # okay, known whitespace option
353                 *)
354                         die "fatal: Invalid whitespace option: '${1#*=}'"
355                         ;;
356                 esac
357                 ;;
358         --ignore-whitespace)
359                 git_am_opt="$git_am_opt $1"
360                 ;;
361         --signoff)
362                 signoff=--signoff
363                 ;;
364         --no-signoff)
365                 signoff=
366                 ;;
367         --committer-date-is-author-date|--ignore-date)
368                 git_am_opt="$git_am_opt $1"
369                 force_rebase=t
370                 ;;
371         -C*[!0-9]*)
372                 die "fatal: switch \`C' expects a numerical value"
373                 ;;
374         -C*)
375                 git_am_opt="$git_am_opt $1"
376                 ;;
377         --root)
378                 rebase_root=t
379                 ;;
380         --force-rebase|--no-ff)
381                 force_rebase=t
382                 ;;
383         --rerere-autoupdate|--no-rerere-autoupdate)
384                 allow_rerere_autoupdate="$1"
385                 ;;
386         --gpg-sign)
387                 gpg_sign_opt=-S
388                 ;;
389         --gpg-sign=*)
390                 gpg_sign_opt="-S${1#--gpg-sign=}"
391                 ;;
392         --reschedule-failed-exec)
393                 reschedule_failed_exec=--reschedule-failed-exec
394                 ;;
395         --no-reschedule-failed-exec)
396                 reschedule_failed_exec=
397                 ;;
398         --)
399                 shift
400                 break
401                 ;;
402         *)
403                 usage
404                 ;;
405         esac
406         shift
407 done
408 test $# -gt 2 && usage
409
410 if test -n "$action"
411 then
412         test -z "$in_progress" && die "$(gettext "No rebase in progress?")"
413         # Only interactive rebase uses detailed reflog messages
414         if test -n "$interactive_rebase" && test "$GIT_REFLOG_ACTION" = rebase
415         then
416                 GIT_REFLOG_ACTION="rebase -i ($action)"
417                 export GIT_REFLOG_ACTION
418         fi
419 fi
420
421 if test "$action" = "edit-todo" && test -z "$interactive_rebase"
422 then
423         die "$(gettext "The --edit-todo action can only be used during interactive rebase.")"
424 fi
425
426 case "$action" in
427 continue)
428         # Sanity check
429         git rev-parse --verify HEAD >/dev/null ||
430                 die "$(gettext "Cannot read HEAD")"
431         git update-index --ignore-submodules --refresh &&
432         git diff-files --quiet --ignore-submodules || {
433                 echo "$(gettext "You must edit all merge conflicts and then
434 mark them as resolved using git add")"
435                 exit 1
436         }
437         read_basic_state
438         run_specific_rebase
439         ;;
440 skip)
441         output git reset --hard HEAD || exit $?
442         read_basic_state
443         run_specific_rebase
444         ;;
445 abort)
446         git rerere clear
447         read_basic_state
448         case "$head_name" in
449         refs/*)
450                 git symbolic-ref -m "rebase: aborting" HEAD $head_name ||
451                 die "$(eval_gettext "Could not move back to \$head_name")"
452                 ;;
453         esac
454         output git reset --hard $orig_head
455         finish_rebase
456         exit
457         ;;
458 quit)
459         exec rm -rf "$state_dir"
460         ;;
461 edit-todo)
462         run_specific_rebase
463         ;;
464 show-current-patch)
465         run_specific_rebase
466         die "BUG: run_specific_rebase is not supposed to return here"
467         ;;
468 esac
469
470 # Make sure no rebase is in progress
471 if test -n "$in_progress"
472 then
473         state_dir_base=${state_dir##*/}
474         cmd_live_rebase="git rebase (--continue | --abort | --skip)"
475         cmd_clear_stale_rebase="rm -fr \"$state_dir\""
476         die "
477 $(eval_gettext 'It seems that there is already a $state_dir_base directory, and
478 I wonder if you are in the middle of another rebase.  If that is the
479 case, please try
480         $cmd_live_rebase
481 If that is not the case, please
482         $cmd_clear_stale_rebase
483 and run me again.  I am stopping in case you still have something
484 valuable there.')"
485 fi
486
487 if test -n "$rebase_root" && test -z "$onto"
488 then
489         test -z "$interactive_rebase" && interactive_rebase=implied
490 fi
491
492 if test -n "$keep_empty"
493 then
494         test -z "$interactive_rebase" && interactive_rebase=implied
495 fi
496
497 actually_interactive=
498 if test -n "$interactive_rebase"
499 then
500         if test -z "$preserve_merges"
501         then
502                 type=interactive
503         else
504                 type=preserve-merges
505         fi
506         actually_interactive=t
507         state_dir="$merge_dir"
508 elif test -n "$do_merge"
509 then
510         interactive_rebase=implied
511         type=interactive
512         state_dir="$merge_dir"
513 else
514         type=am
515         state_dir="$apply_dir"
516 fi
517
518 if test -t 2 && test -z "$GIT_QUIET"
519 then
520         git_format_patch_opt="$git_format_patch_opt --progress"
521 fi
522
523 incompatible_opts=$(echo " $git_am_opt " | \
524                     sed -e 's/ -q / /g' -e 's/^ \(.*\) $/\1/')
525 if test -n "$incompatible_opts"
526 then
527         if test -n "$actually_interactive" || test "$do_merge"
528         then
529                 die "$(gettext "fatal: cannot combine am options with either interactive or merge options")"
530         fi
531 fi
532
533 if test -n "$signoff"
534 then
535         test -n "$preserve_merges" &&
536                 die "$(gettext "fatal: cannot combine '--signoff' with '--preserve-merges'")"
537         git_am_opt="$git_am_opt $signoff"
538         force_rebase=t
539 fi
540
541 if test -n "$preserve_merges"
542 then
543         # Note: incompatibility with --signoff handled in signoff block above
544         # Note: incompatibility with --interactive is just a strong warning;
545         #       git-rebase.txt caveats with "unless you know what you are doing"
546         test -n "$rebase_merges" &&
547                 die "$(gettext "fatal: cannot combine '--preserve-merges' with '--rebase-merges'")"
548
549         test -n "$reschedule_failed_exec" &&
550                 die "$(gettext "error: cannot combine '--preserve-merges' with '--reschedule-failed-exec'")"
551 fi
552
553 if test -n "$rebase_merges"
554 then
555         test -n "$strategy_opts" &&
556                 die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy-option'")"
557         test -n "$strategy" &&
558                 die "$(gettext "fatal: cannot combine '--rebase-merges' with '--strategy'")"
559 fi
560
561 if test -z "$rebase_root"
562 then
563         case "$#" in
564         0)
565                 if ! upstream_name=$(git rev-parse --symbolic-full-name \
566                         --verify -q @{upstream} 2>/dev/null)
567                 then
568                         . git-parse-remote
569                         error_on_missing_default_upstream "rebase" "rebase" \
570                                 "against" "git rebase $(gettext '<branch>')"
571                 fi
572
573                 test "$fork_point" = auto && fork_point=t
574                 ;;
575         *)      upstream_name="$1"
576                 if test "$upstream_name" = "-"
577                 then
578                         upstream_name="@{-1}"
579                 fi
580                 shift
581                 ;;
582         esac
583         upstream=$(peel_committish "${upstream_name}") ||
584         die "$(eval_gettext "invalid upstream '\$upstream_name'")"
585         upstream_arg="$upstream_name"
586 else
587         if test -z "$onto"
588         then
589                 empty_tree=$(git hash-object -t tree /dev/null)
590                 onto=$(git commit-tree $empty_tree </dev/null)
591                 squash_onto="$onto"
592         fi
593         unset upstream_name
594         unset upstream
595         test $# -gt 1 && usage
596         upstream_arg=--root
597 fi
598
599 # Make sure the branch to rebase onto is valid.
600 onto_name=${onto-"$upstream_name"}
601 case "$onto_name" in
602 *...*)
603         if      left=${onto_name%...*} right=${onto_name#*...} &&
604                 onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
605         then
606                 case "$onto" in
607                 ?*"$LF"?*)
608                         die "$(eval_gettext "\$onto_name: there are more than one merge bases")"
609                         ;;
610                 '')
611                         die "$(eval_gettext "\$onto_name: there is no merge base")"
612                         ;;
613                 esac
614         else
615                 die "$(eval_gettext "\$onto_name: there is no merge base")"
616         fi
617         ;;
618 *)
619         onto=$(peel_committish "$onto_name") ||
620         die "$(eval_gettext "Does not point to a valid commit: \$onto_name")"
621         ;;
622 esac
623
624 # If the branch to rebase is given, that is the branch we will rebase
625 # $branch_name -- branch/commit being rebased, or HEAD (already detached)
626 # $orig_head -- commit object name of tip of the branch before rebasing
627 # $head_name -- refs/heads/<that-branch> or "detached HEAD"
628 switch_to=
629 case "$#" in
630 1)
631         # Is it "rebase other $branchname" or "rebase other $commit"?
632         branch_name="$1"
633         switch_to="$1"
634
635         # Is it a local branch?
636         if git show-ref --verify --quiet -- "refs/heads/$branch_name" &&
637            orig_head=$(git rev-parse -q --verify "refs/heads/$branch_name")
638         then
639                 head_name="refs/heads/$branch_name"
640         # If not is it a valid ref (branch or commit)?
641         elif orig_head=$(git rev-parse -q --verify "$branch_name")
642         then
643                 head_name="detached HEAD"
644
645         else
646                 die "$(eval_gettext "fatal: no such branch/commit '\$branch_name'")"
647         fi
648         ;;
649 0)
650         # Do not need to switch branches, we are already on it.
651         if branch_name=$(git symbolic-ref -q HEAD)
652         then
653                 head_name=$branch_name
654                 branch_name=$(expr "z$branch_name" : 'zrefs/heads/\(.*\)')
655         else
656                 head_name="detached HEAD"
657                 branch_name=HEAD
658         fi
659         orig_head=$(git rev-parse --verify HEAD) || exit
660         ;;
661 *)
662         die "BUG: unexpected number of arguments left to parse"
663         ;;
664 esac
665
666 if test "$fork_point" = t
667 then
668         new_upstream=$(git merge-base --fork-point "$upstream_name" \
669                         "${switch_to:-HEAD}")
670         if test -n "$new_upstream"
671         then
672                 restrict_revision=$new_upstream
673         fi
674 fi
675
676 if test "$autostash" = true && ! (require_clean_work_tree) 2>/dev/null
677 then
678         stash_sha1=$(git stash create "autostash") ||
679         die "$(gettext 'Cannot autostash')"
680
681         mkdir -p "$state_dir" &&
682         echo $stash_sha1 >"$state_dir/autostash" &&
683         stash_abbrev=$(git rev-parse --short $stash_sha1) &&
684         echo "$(eval_gettext 'Created autostash: $stash_abbrev')" &&
685         git reset --hard
686 fi
687
688 require_clean_work_tree "rebase" "$(gettext "Please commit or stash them.")"
689
690 # Now we are rebasing commits $upstream..$orig_head (or with --root,
691 # everything leading up to $orig_head) on top of $onto
692
693 # Check if we are already based on $onto with linear history,
694 # but this should be done only when upstream and onto are the same
695 # and if this is not an interactive rebase.
696 mb=$(git merge-base "$onto" "$orig_head")
697 if test -z "$actually_interactive" && test "$upstream" = "$onto" &&
698         test "$mb" = "$onto" && test -z "$restrict_revision" &&
699         # linear history?
700         ! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
701 then
702         if test -z "$force_rebase"
703         then
704                 # Lazily switch to the target branch if needed...
705                 test -z "$switch_to" ||
706                 GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $switch_to" \
707                         git checkout -q "$switch_to" --
708                 if test "$branch_name" = "HEAD" &&
709                          ! git symbolic-ref -q HEAD
710                 then
711                         say "$(eval_gettext "HEAD is up to date.")"
712                 else
713                         say "$(eval_gettext "Current branch \$branch_name is up to date.")"
714                 fi
715                 finish_rebase
716                 exit 0
717         else
718                 if test "$branch_name" = "HEAD" &&
719                          ! git symbolic-ref -q HEAD
720                 then
721                         say "$(eval_gettext "HEAD is up to date, rebase forced.")"
722                 else
723                         say "$(eval_gettext "Current branch \$branch_name is up to date, rebase forced.")"
724                 fi
725         fi
726 fi
727
728 # If a hook exists, give it a chance to interrupt
729 run_pre_rebase_hook "$upstream_arg" "$@"
730
731 if test -n "$diffstat"
732 then
733         if test -n "$verbose"
734         then
735                 if test -z "$mb"
736                 then
737                         echo "$(eval_gettext "Changes to \$onto:")"
738                 else
739                         echo "$(eval_gettext "Changes from \$mb to \$onto:")"
740                 fi
741         fi
742         mb_tree="${mb:-$(git hash-object -t tree /dev/null)}"
743         # We want color (if set), but no pager
744         GIT_PAGER='' git diff --stat --summary "$mb_tree" "$onto"
745 fi
746
747 if test -z "$actually_interactive" && test "$mb" = "$orig_head"
748 then
749         say "$(eval_gettext "Fast-forwarded \$branch_name to \$onto_name.")"
750         GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
751                 git checkout -q "$onto^0" || die "could not detach HEAD"
752         # If the $onto is a proper descendant of the tip of the branch, then
753         # we just fast-forwarded.
754         git update-ref ORIG_HEAD $orig_head
755         move_to_original_branch
756         finish_rebase
757         exit 0
758 fi
759
760 test -n "$interactive_rebase" && run_specific_rebase
761
762 # Detach HEAD and reset the tree
763 say "$(gettext "First, rewinding head to replay your work on top of it...")"
764
765 GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name" \
766         git checkout -q "$onto^0" || die "could not detach HEAD"
767 git update-ref ORIG_HEAD $orig_head
768
769 if test -n "$rebase_root"
770 then
771         revisions="$onto..$orig_head"
772 else
773         revisions="${restrict_revision-$upstream}..$orig_head"
774 fi
775
776 run_specific_rebase