Code

rebase -i: interrupt rebase when "commit --amend" failed during "reword"
[git.git] / git-rebase--interactive.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2006 Johannes E. Schindelin
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
13 . git-sh-setup
15 # The file containing rebase commands, comments, and empty lines.
16 # This file is created by "git rebase -i" then edited by the user.  As
17 # the lines are processed, they are removed from the front of this
18 # file and written to the tail of $done.
19 todo="$state_dir"/git-rebase-todo
21 # The rebase command lines that have already been processed.  A line
22 # is moved here when it is first handled, before any associated user
23 # actions.
24 done="$state_dir"/done
26 # The commit message that is planned to be used for any changes that
27 # need to be committed following a user interaction.
28 msg="$state_dir"/message
30 # The file into which is accumulated the suggested commit message for
31 # squash/fixup commands.  When the first of a series of squash/fixups
32 # is seen, the file is created and the commit message from the
33 # previous commit and from the first squash/fixup commit are written
34 # to it.  The commit message for each subsequent squash/fixup commit
35 # is appended to the file as it is processed.
36 #
37 # The first line of the file is of the form
38 #     # This is a combination of $count commits.
39 # where $count is the number of commits whose messages have been
40 # written to the file so far (including the initial "pick" commit).
41 # Each time that a commit message is processed, this line is read and
42 # updated.  It is deleted just before the combined commit is made.
43 squash_msg="$state_dir"/message-squash
45 # If the current series of squash/fixups has not yet included a squash
46 # command, then this file exists and holds the commit message of the
47 # original "pick" commit.  (If the series ends without a "squash"
48 # command, then this can be used as the commit message of the combined
49 # commit without opening the editor.)
50 fixup_msg="$state_dir"/message-fixup
52 # $rewritten is the name of a directory containing files for each
53 # commit that is reachable by at least one merge base of $head and
54 # $upstream. They are not necessarily rewritten, but their children
55 # might be.  This ensures that commits on merged, but otherwise
56 # unrelated side branches are left alone. (Think "X" in the man page's
57 # example.)
58 rewritten="$state_dir"/rewritten
60 dropped="$state_dir"/dropped
62 # A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
63 # GIT_AUTHOR_DATE that will be used for the commit that is currently
64 # being rebased.
65 author_script="$state_dir"/author-script
67 # When an "edit" rebase command is being processed, the SHA1 of the
68 # commit to be edited is recorded in this file.  When "git rebase
69 # --continue" is executed, if there are any staged changes then they
70 # will be amended to the HEAD commit, but only provided the HEAD
71 # commit is still the commit to be edited.  When any other rebase
72 # command is processed, this file is deleted.
73 amend="$state_dir"/amend
75 # For the post-rewrite hook, we make a list of rewritten commits and
76 # their new sha1s.  The rewritten-pending list keeps the sha1s of
77 # commits that have been processed, but not committed yet,
78 # e.g. because they are waiting for a 'squash' command.
79 rewritten_list="$state_dir"/rewritten-list
80 rewritten_pending="$state_dir"/rewritten-pending
82 GIT_CHERRY_PICK_HELP="$resolvemsg"
83 export GIT_CHERRY_PICK_HELP
85 warn () {
86         printf '%s\n' "$*" >&2
87 }
89 # Output the commit message for the specified commit.
90 commit_message () {
91         git cat-file commit "$1" | sed "1,/^$/d"
92 }
94 orig_reflog_action="$GIT_REFLOG_ACTION"
96 comment_for_reflog () {
97         case "$orig_reflog_action" in
98         ''|rebase*)
99                 GIT_REFLOG_ACTION="rebase -i ($1)"
100                 export GIT_REFLOG_ACTION
101                 ;;
102         esac
105 last_count=
106 mark_action_done () {
107         sed -e 1q < "$todo" >> "$done"
108         sed -e 1d < "$todo" >> "$todo".new
109         mv -f "$todo".new "$todo"
110         new_count=$(sane_grep -c '^[^#]' < "$done")
111         total=$(($new_count+$(sane_grep -c '^[^#]' < "$todo")))
112         if test "$last_count" != "$new_count"
113         then
114                 last_count=$new_count
115                 printf "Rebasing (%d/%d)\r" $new_count $total
116                 test -z "$verbose" || echo
117         fi
120 make_patch () {
121         sha1_and_parents="$(git rev-list --parents -1 "$1")"
122         case "$sha1_and_parents" in
123         ?*' '?*' '?*)
124                 git diff --cc $sha1_and_parents
125                 ;;
126         ?*' '?*)
127                 git diff-tree -p "$1^!"
128                 ;;
129         *)
130                 echo "Root commit"
131                 ;;
132         esac > "$state_dir"/patch
133         test -f "$msg" ||
134                 commit_message "$1" > "$msg"
135         test -f "$author_script" ||
136                 get_author_ident_from_commit "$1" > "$author_script"
139 die_with_patch () {
140         echo "$1" > "$state_dir"/stopped-sha
141         make_patch "$1"
142         git rerere
143         die "$2"
146 exit_with_patch () {
147         echo "$1" > "$state_dir"/stopped-sha
148         make_patch $1
149         git rev-parse --verify HEAD > "$amend"
150         warn "You can amend the commit now, with"
151         warn
152         warn "  git commit --amend"
153         warn
154         warn "Once you are satisfied with your changes, run"
155         warn
156         warn "  git rebase --continue"
157         warn
158         exit $2
161 die_abort () {
162         rm -rf "$state_dir"
163         die "$1"
166 has_action () {
167         sane_grep '^[^#]' "$1" >/dev/null
170 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
171 # GIT_AUTHOR_DATE exported from the current environment.
172 do_with_author () {
173         (
174                 export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
175                 "$@"
176         )
179 pick_one () {
180         ff=--ff
181         case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
182         case "$force_rebase" in '') ;; ?*) ff= ;; esac
183         output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
184         test -d "$rewritten" &&
185                 pick_one_preserving_merges "$@" && return
186         output git cherry-pick $ff "$@"
189 pick_one_preserving_merges () {
190         fast_forward=t
191         case "$1" in
192         -n)
193                 fast_forward=f
194                 sha1=$2
195                 ;;
196         *)
197                 sha1=$1
198                 ;;
199         esac
200         sha1=$(git rev-parse $sha1)
202         if test -f "$state_dir"/current-commit
203         then
204                 if test "$fast_forward" = t
205                 then
206                         while read current_commit
207                         do
208                                 git rev-parse HEAD > "$rewritten"/$current_commit
209                         done <"$state_dir"/current-commit
210                         rm "$state_dir"/current-commit ||
211                         die "Cannot write current commit's replacement sha1"
212                 fi
213         fi
215         echo $sha1 >> "$state_dir"/current-commit
217         # rewrite parents; if none were rewritten, we can fast-forward.
218         new_parents=
219         pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
220         if test "$pend" = " "
221         then
222                 pend=" root"
223         fi
224         while [ "$pend" != "" ]
225         do
226                 p=$(expr "$pend" : ' \([^ ]*\)')
227                 pend="${pend# $p}"
229                 if test -f "$rewritten"/$p
230                 then
231                         new_p=$(cat "$rewritten"/$p)
233                         # If the todo reordered commits, and our parent is marked for
234                         # rewriting, but hasn't been gotten to yet, assume the user meant to
235                         # drop it on top of the current HEAD
236                         if test -z "$new_p"
237                         then
238                                 new_p=$(git rev-parse HEAD)
239                         fi
241                         test $p != $new_p && fast_forward=f
242                         case "$new_parents" in
243                         *$new_p*)
244                                 ;; # do nothing; that parent is already there
245                         *)
246                                 new_parents="$new_parents $new_p"
247                                 ;;
248                         esac
249                 else
250                         if test -f "$dropped"/$p
251                         then
252                                 fast_forward=f
253                                 replacement="$(cat "$dropped"/$p)"
254                                 test -z "$replacement" && replacement=root
255                                 pend=" $replacement$pend"
256                         else
257                                 new_parents="$new_parents $p"
258                         fi
259                 fi
260         done
261         case $fast_forward in
262         t)
263                 output warn "Fast-forward to $sha1"
264                 output git reset --hard $sha1 ||
265                         die "Cannot fast-forward to $sha1"
266                 ;;
267         f)
268                 first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
270                 if [ "$1" != "-n" ]
271                 then
272                         # detach HEAD to current parent
273                         output git checkout $first_parent 2> /dev/null ||
274                                 die "Cannot move HEAD to $first_parent"
275                 fi
277                 case "$new_parents" in
278                 ' '*' '*)
279                         test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
281                         # redo merge
282                         author_script_content=$(get_author_ident_from_commit $sha1)
283                         eval "$author_script_content"
284                         msg_content="$(commit_message $sha1)"
285                         # No point in merging the first parent, that's HEAD
286                         new_parents=${new_parents# $first_parent}
287                         if ! do_with_author output \
288                                 git merge --no-ff ${strategy:+-s $strategy} -m \
289                                         "$msg_content" $new_parents
290                         then
291                                 printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
292                                 die_with_patch $sha1 "Error redoing merge $sha1"
293                         fi
294                         echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
295                         ;;
296                 *)
297                         output git cherry-pick "$@" ||
298                                 die_with_patch $sha1 "Could not pick $sha1"
299                         ;;
300                 esac
301                 ;;
302         esac
305 nth_string () {
306         case "$1" in
307         *1[0-9]|*[04-9]) echo "$1"th;;
308         *1) echo "$1"st;;
309         *2) echo "$1"nd;;
310         *3) echo "$1"rd;;
311         esac
314 update_squash_messages () {
315         if test -f "$squash_msg"; then
316                 mv "$squash_msg" "$squash_msg".bak || exit
317                 count=$(($(sed -n \
318                         -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
319                         -e "q" < "$squash_msg".bak)+1))
320                 {
321                         echo "# This is a combination of $count commits."
322                         sed -e 1d -e '2,/^./{
323                                 /^$/d
324                         }' <"$squash_msg".bak
325                 } >"$squash_msg"
326         else
327                 commit_message HEAD > "$fixup_msg" || die "Cannot write $fixup_msg"
328                 count=2
329                 {
330                         echo "# This is a combination of 2 commits."
331                         echo "# The first commit's message is:"
332                         echo
333                         cat "$fixup_msg"
334                 } >"$squash_msg"
335         fi
336         case $1 in
337         squash)
338                 rm -f "$fixup_msg"
339                 echo
340                 echo "# This is the $(nth_string $count) commit message:"
341                 echo
342                 commit_message $2
343                 ;;
344         fixup)
345                 echo
346                 echo "# The $(nth_string $count) commit message will be skipped:"
347                 echo
348                 commit_message $2 | sed -e 's/^/#       /'
349                 ;;
350         esac >>"$squash_msg"
353 peek_next_command () {
354         sed -n -e "/^#/d" -e '/^$/d' -e "s/ .*//p" -e "q" < "$todo"
357 # A squash/fixup has failed.  Prepare the long version of the squash
358 # commit message, then die_with_patch.  This code path requires the
359 # user to edit the combined commit message for all commits that have
360 # been squashed/fixedup so far.  So also erase the old squash
361 # messages, effectively causing the combined commit to be used as the
362 # new basis for any further squash/fixups.  Args: sha1 rest
363 die_failed_squash() {
364         mv "$squash_msg" "$msg" || exit
365         rm -f "$fixup_msg"
366         cp "$msg" "$GIT_DIR"/MERGE_MSG || exit
367         warn
368         warn "Could not apply $1... $2"
369         die_with_patch $1 ""
372 flush_rewritten_pending() {
373         test -s "$rewritten_pending" || return
374         newsha1="$(git rev-parse HEAD^0)"
375         sed "s/$/ $newsha1/" < "$rewritten_pending" >> "$rewritten_list"
376         rm -f "$rewritten_pending"
379 record_in_rewritten() {
380         oldsha1="$(git rev-parse $1)"
381         echo "$oldsha1" >> "$rewritten_pending"
383         case "$(peek_next_command)" in
384         squash|s|fixup|f)
385                 ;;
386         *)
387                 flush_rewritten_pending
388                 ;;
389         esac
392 do_next () {
393         rm -f "$msg" "$author_script" "$amend" || exit
394         read -r command sha1 rest < "$todo"
395         case "$command" in
396         '#'*|''|noop)
397                 mark_action_done
398                 ;;
399         pick|p)
400                 comment_for_reflog pick
402                 mark_action_done
403                 pick_one $sha1 ||
404                         die_with_patch $sha1 "Could not apply $sha1... $rest"
405                 record_in_rewritten $sha1
406                 ;;
407         reword|r)
408                 comment_for_reflog reword
410                 mark_action_done
411                 pick_one $sha1 ||
412                         die_with_patch $sha1 "Could not apply $sha1... $rest"
413                 git commit --amend --no-post-rewrite || {
414                         warn "Could not amend commit after successfully picking $sha1... $rest"
415                         warn "This is most likely due to an empty commit message, or the pre-commit hook"
416                         warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
417                         warn "you are able to reword the commit."
418                         exit_with_patch $sha1 1
419                 }
420                 record_in_rewritten $sha1
421                 ;;
422         edit|e)
423                 comment_for_reflog edit
425                 mark_action_done
426                 pick_one $sha1 ||
427                         die_with_patch $sha1 "Could not apply $sha1... $rest"
428                 warn "Stopped at $sha1... $rest"
429                 exit_with_patch $sha1 0
430                 ;;
431         squash|s|fixup|f)
432                 case "$command" in
433                 squash|s)
434                         squash_style=squash
435                         ;;
436                 fixup|f)
437                         squash_style=fixup
438                         ;;
439                 esac
440                 comment_for_reflog $squash_style
442                 test -f "$done" && has_action "$done" ||
443                         die "Cannot '$squash_style' without a previous commit"
445                 mark_action_done
446                 update_squash_messages $squash_style $sha1
447                 author_script_content=$(get_author_ident_from_commit HEAD)
448                 echo "$author_script_content" > "$author_script"
449                 eval "$author_script_content"
450                 output git reset --soft HEAD^
451                 pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
452                 case "$(peek_next_command)" in
453                 squash|s|fixup|f)
454                         # This is an intermediate commit; its message will only be
455                         # used in case of trouble.  So use the long version:
456                         do_with_author output git commit --no-verify -F "$squash_msg" ||
457                                 die_failed_squash $sha1 "$rest"
458                         ;;
459                 *)
460                         # This is the final command of this squash/fixup group
461                         if test -f "$fixup_msg"
462                         then
463                                 do_with_author git commit --no-verify -F "$fixup_msg" ||
464                                         die_failed_squash $sha1 "$rest"
465                         else
466                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
467                                 rm -f "$GIT_DIR"/MERGE_MSG
468                                 do_with_author git commit --no-verify -e ||
469                                         die_failed_squash $sha1 "$rest"
470                         fi
471                         rm -f "$squash_msg" "$fixup_msg"
472                         ;;
473                 esac
474                 record_in_rewritten $sha1
475                 ;;
476         x|"exec")
477                 read -r command rest < "$todo"
478                 mark_action_done
479                 printf 'Executing: %s\n' "$rest"
480                 # "exec" command doesn't take a sha1 in the todo-list.
481                 # => can't just use $sha1 here.
482                 git rev-parse --verify HEAD > "$state_dir"/stopped-sha
483                 ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
484                 status=$?
485                 # Run in subshell because require_clean_work_tree can die.
486                 dirty=f
487                 (require_clean_work_tree "rebase" 2>/dev/null) || dirty=t
488                 if test "$status" -ne 0
489                 then
490                         warn "Execution failed: $rest"
491                         test "$dirty" = f ||
492                         warn "and made changes to the index and/or the working tree"
494                         warn "You can fix the problem, and then run"
495                         warn
496                         warn "  git rebase --continue"
497                         warn
498                         exit "$status"
499                 elif test "$dirty" = t
500                 then
501                         warn "Execution succeeded: $rest"
502                         warn "but left changes to the index and/or the working tree"
503                         warn "Commit or stash your changes, and then run"
504                         warn
505                         warn "  git rebase --continue"
506                         warn
507                         exit 1
508                 fi
509                 ;;
510         *)
511                 warn "Unknown command: $command $sha1 $rest"
512                 if git rev-parse --verify -q "$sha1" >/dev/null
513                 then
514                         die_with_patch $sha1 "Please fix this in the file $todo."
515                 else
516                         die "Please fix this in the file $todo."
517                 fi
518                 ;;
519         esac
520         test -s "$todo" && return
522         comment_for_reflog finish &&
523         shortonto=$(git rev-parse --short $onto) &&
524         newhead=$(git rev-parse HEAD) &&
525         case $head_name in
526         refs/*)
527                 message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
528                 git update-ref -m "$message" $head_name $newhead $orig_head &&
529                 git symbolic-ref \
530                   -m "$GIT_REFLOG_ACTION: returning to $head_name" \
531                   HEAD $head_name
532                 ;;
533         esac && {
534                 test ! -f "$state_dir"/verbose ||
535                         git diff-tree --stat $orig_head..HEAD
536         } &&
537         {
538                 test -s "$rewritten_list" &&
539                 git notes copy --for-rewrite=rebase < "$rewritten_list" ||
540                 true # we don't care if this copying failed
541         } &&
542         if test -x "$GIT_DIR"/hooks/post-rewrite &&
543                 test -s "$rewritten_list"; then
544                 "$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
545                 true # we don't care if this hook failed
546         fi &&
547         rm -rf "$state_dir" &&
548         git gc --auto &&
549         warn "Successfully rebased and updated $head_name."
551         exit
554 do_rest () {
555         while :
556         do
557                 do_next
558         done
561 # skip picking commits whose parents are unchanged
562 skip_unnecessary_picks () {
563         fd=3
564         while read -r command rest
565         do
566                 # fd=3 means we skip the command
567                 case "$fd,$command" in
568                 3,pick|3,p)
569                         # pick a commit whose parent is current $onto -> skip
570                         sha1=${rest%% *}
571                         case "$(git rev-parse --verify --quiet "$sha1"^)" in
572                         "$onto"*)
573                                 onto=$sha1
574                                 ;;
575                         *)
576                                 fd=1
577                                 ;;
578                         esac
579                         ;;
580                 3,#*|3,)
581                         # copy comments
582                         ;;
583                 *)
584                         fd=1
585                         ;;
586                 esac
587                 printf '%s\n' "$command${rest:+ }$rest" >&$fd
588         done <"$todo" >"$todo.new" 3>>"$done" &&
589         mv -f "$todo".new "$todo" &&
590         case "$(peek_next_command)" in
591         squash|s|fixup|f)
592                 record_in_rewritten "$onto"
593                 ;;
594         esac ||
595         die "Could not skip unnecessary pick commands"
598 # Rearrange the todo list that has both "pick sha1 msg" and
599 # "pick sha1 fixup!/squash! msg" appears in it so that the latter
600 # comes immediately after the former, and change "pick" to
601 # "fixup"/"squash".
602 rearrange_squash () {
603         # extract fixup!/squash! lines and resolve any referenced sha1's
604         while read -r pick sha1 message
605         do
606                 case "$message" in
607                 "squash! "*|"fixup! "*)
608                         action="${message%%!*}"
609                         rest="${message#*! }"
610                         echo "$sha1 $action $rest"
611                         # if it's a single word, try to resolve to a full sha1 and
612                         # emit a second copy. This allows us to match on both message
613                         # and on sha1 prefix
614                         if test "${rest#* }" = "$rest"; then
615                                 fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)"
616                                 if test -n "$fullsha"; then
617                                         # prefix the action to uniquely identify this line as
618                                         # intended for full sha1 match
619                                         echo "$sha1 +$action $fullsha"
620                                 fi
621                         fi
622                 esac
623         done >"$1.sq" <"$1"
624         test -s "$1.sq" || return
626         used=
627         while read -r pick sha1 message
628         do
629                 case " $used" in
630                 *" $sha1 "*) continue ;;
631                 esac
632                 printf '%s\n' "$pick $sha1 $message"
633                 used="$used$sha1 "
634                 while read -r squash action msg_content
635                 do
636                         case " $used" in
637                         *" $squash "*) continue ;;
638                         esac
639                         emit=0
640                         case "$action" in
641                         +*)
642                                 action="${action#+}"
643                                 # full sha1 prefix test
644                                 case "$msg_content" in "$sha1"*) emit=1;; esac ;;
645                         *)
646                                 # message prefix test
647                                 case "$message" in "$msg_content"*) emit=1;; esac ;;
648                         esac
649                         if test $emit = 1; then
650                                 printf '%s\n' "$action $squash $action! $msg_content"
651                                 used="$used$squash "
652                         fi
653                 done <"$1.sq"
654         done >"$1.rearranged" <"$1"
655         cat "$1.rearranged" >"$1"
656         rm -f "$1.sq" "$1.rearranged"
659 case "$action" in
660 continue)
661         # do we have anything to commit?
662         if git diff-index --cached --quiet --ignore-submodules HEAD --
663         then
664                 : Nothing to commit -- skip this
665         else
666                 if ! test -f "$author_script"
667                 then
668                         die "You have staged changes in your working tree. If these changes are meant to be
669 squashed into the previous commit, run:
671   git commit --amend
673 If they are meant to go into a new commit, run:
675   git commit
677 In both case, once you're done, continue with:
679   git rebase --continue
681                 fi
682                 . "$author_script" ||
683                         die "Error trying to find the author identity to amend commit"
684                 current_head=
685                 if test -f "$amend"
686                 then
687                         current_head=$(git rev-parse --verify HEAD)
688                         test "$current_head" = $(cat "$amend") ||
689                         die "\
690 You have uncommitted changes in your working tree. Please, commit them
691 first and then run 'git rebase --continue' again."
692                         git reset --soft HEAD^ ||
693                         die "Cannot rewind the HEAD"
694                 fi
695                 do_with_author git commit --no-verify -F "$msg" -e || {
696                         test -n "$current_head" && git reset --soft $current_head
697                         die "Could not commit staged changes."
698                 }
699         fi
701         record_in_rewritten "$(cat "$state_dir"/stopped-sha)"
703         require_clean_work_tree "rebase"
704         do_rest
705         ;;
706 skip)
707         git rerere clear
709         do_rest
710         ;;
711 esac
713 git var GIT_COMMITTER_IDENT >/dev/null ||
714         die "You need to set your committer info first"
716 comment_for_reflog start
718 if test ! -z "$switch_to"
719 then
720         output git checkout "$switch_to" -- ||
721                 die "Could not checkout $switch_to"
722 fi
724 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
725 mkdir "$state_dir" || die "Could not create temporary $state_dir"
727 : > "$state_dir"/interactive || die "Could not mark as interactive"
728 write_basic_state
729 if test t = "$preserve_merges"
730 then
731         if test -z "$rebase_root"
732         then
733                 mkdir "$rewritten" &&
734                 for c in $(git merge-base --all $orig_head $upstream)
735                 do
736                         echo $onto > "$rewritten"/$c ||
737                                 die "Could not init rewritten commits"
738                 done
739         else
740                 mkdir "$rewritten" &&
741                 echo $onto > "$rewritten"/root ||
742                         die "Could not init rewritten commits"
743         fi
744         # No cherry-pick because our first pass is to determine
745         # parents to rewrite and skipping dropped commits would
746         # prematurely end our probe
747         merges_option=
748 else
749         merges_option="--no-merges --cherry-pick"
750 fi
752 shorthead=$(git rev-parse --short $orig_head)
753 shortonto=$(git rev-parse --short $onto)
754 if test -z "$rebase_root"
755         # this is now equivalent to ! -z "$upstream"
756 then
757         shortupstream=$(git rev-parse --short $upstream)
758         revisions=$upstream...$orig_head
759         shortrevisions=$shortupstream..$shorthead
760 else
761         revisions=$onto...$orig_head
762         shortrevisions=$shorthead
763 fi
764 git rev-list $merges_option --pretty=oneline --abbrev-commit \
765         --abbrev=7 --reverse --left-right --topo-order \
766         $revisions | \
767         sed -n "s/^>//p" |
768 while read -r shortsha1 rest
769 do
770         if test t != "$preserve_merges"
771         then
772                 printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
773         else
774                 sha1=$(git rev-parse $shortsha1)
775                 if test -z "$rebase_root"
776                 then
777                         preserve=t
778                         for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
779                         do
780                                 if test -f "$rewritten"/$p
781                                 then
782                                         preserve=f
783                                 fi
784                         done
785                 else
786                         preserve=f
787                 fi
788                 if test f = "$preserve"
789                 then
790                         touch "$rewritten"/$sha1
791                         printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
792                 fi
793         fi
794 done
796 # Watch for commits that been dropped by --cherry-pick
797 if test t = "$preserve_merges"
798 then
799         mkdir "$dropped"
800         # Save all non-cherry-picked changes
801         git rev-list $revisions --left-right --cherry-pick | \
802                 sed -n "s/^>//p" > "$state_dir"/not-cherry-picks
803         # Now all commits and note which ones are missing in
804         # not-cherry-picks and hence being dropped
805         git rev-list $revisions |
806         while read rev
807         do
808                 if test -f "$rewritten"/$rev -a "$(sane_grep "$rev" "$state_dir"/not-cherry-picks)" = ""
809                 then
810                         # Use -f2 because if rev-list is telling us this commit is
811                         # not worthwhile, we don't want to track its multiple heads,
812                         # just the history of its first-parent for others that will
813                         # be rebasing on top of it
814                         git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$dropped"/$rev
815                         short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
816                         sane_grep -v "^[a-z][a-z]* $short" <"$todo" > "${todo}2" ; mv "${todo}2" "$todo"
817                         rm "$rewritten"/$rev
818                 fi
819         done
820 fi
822 test -s "$todo" || echo noop >> "$todo"
823 test -n "$autosquash" && rearrange_squash "$todo"
824 cat >> "$todo" << EOF
826 # Rebase $shortrevisions onto $shortonto
828 # Commands:
829 #  p, pick = use commit
830 #  r, reword = use commit, but edit the commit message
831 #  e, edit = use commit, but stop for amending
832 #  s, squash = use commit, but meld into previous commit
833 #  f, fixup = like "squash", but discard this commit's log message
834 #  x, exec = run command (the rest of the line) using shell
836 # If you remove a line here THAT COMMIT WILL BE LOST.
837 # However, if you remove everything, the rebase will be aborted.
839 EOF
841 has_action "$todo" ||
842         die_abort "Nothing to do"
844 cp "$todo" "$todo".backup
845 git_editor "$todo" ||
846         die_abort "Could not execute editor"
848 has_action "$todo" ||
849         die_abort "Nothing to do"
851 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
853 output git checkout $onto || die_abort "could not detach HEAD"
854 git update-ref ORIG_HEAD $orig_head
855 do_rest