Merge branch 'maint'
[git] / git-rebase--interactive.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2006 Johannes E. Schindelin
4
5 # SHORT DESCRIPTION
6 #
7 # This script makes it easy to fix up commits in the middle of a series,
8 # and rearrange commits.
9 #
10 # The original idea comes from Eric W. Biederman, in
11 # http://article.gmane.org/gmane.comp.version-control.git/22407
12
13 . git-sh-setup
14
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
20
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="$state_dir"/done
25
26 # The commit message that is planned to be used for any changes that
27 # need to be committed following a user interaction.
28 msg="$state_dir"/message
29
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
44
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
51
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
59
60 dropped="$state_dir"/dropped
61
62 # A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
63 # GIT_AUTHOR_DATE that will be used for the commit that is currently
64 # being rebased.
65 author_script="$state_dir"/author-script
66
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="$state_dir"/amend
74
75 # For the post-rewrite hook, we make a list of rewritten commits and
76 # their new sha1s.  The rewritten-pending list keeps the sha1s of
77 # commits that have been processed, but not committed yet,
78 # e.g. because they are waiting for a 'squash' command.
79 rewritten_list="$state_dir"/rewritten-list
80 rewritten_pending="$state_dir"/rewritten-pending
81
82 GIT_CHERRY_PICK_HELP="$resolvemsg"
83 export GIT_CHERRY_PICK_HELP
84
85 warn () {
86         printf '%s\n' "$*" >&2
87 }
88
89 # Output the commit message for the specified commit.
90 commit_message () {
91         git cat-file commit "$1" | sed "1,/^$/d"
92 }
93
94 orig_reflog_action="$GIT_REFLOG_ACTION"
95
96 comment_for_reflog () {
97         case "$orig_reflog_action" in
98         ''|rebase*)
99                 GIT_REFLOG_ACTION="rebase -i ($1)"
100                 export GIT_REFLOG_ACTION
101                 ;;
102         esac
103 }
104
105 last_count=
106 mark_action_done () {
107         sed -e 1q < "$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
118 }
119
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"
137 }
138
139 die_with_patch () {
140         echo "$1" > "$state_dir"/stopped-sha
141         make_patch "$1"
142         git rerere
143         die "$2"
144 }
145
146 die_abort () {
147         rm -rf "$state_dir"
148         die "$1"
149 }
150
151 has_action () {
152         sane_grep '^[^#]' "$1" >/dev/null
153 }
154
155 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
156 # GIT_AUTHOR_DATE exported from the current environment.
157 do_with_author () {
158         (
159                 export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
160                 "$@"
161         )
162 }
163
164 pick_one () {
165         ff=--ff
166         case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
167         case "$force_rebase" in '') ;; ?*) ff= ;; esac
168         output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
169         test -d "$rewritten" &&
170                 pick_one_preserving_merges "$@" && return
171         output git cherry-pick $ff "$@"
172 }
173
174 pick_one_preserving_merges () {
175         fast_forward=t
176         case "$1" in
177         -n)
178                 fast_forward=f
179                 sha1=$2
180                 ;;
181         *)
182                 sha1=$1
183                 ;;
184         esac
185         sha1=$(git rev-parse $sha1)
186
187         if test -f "$state_dir"/current-commit
188         then
189                 if test "$fast_forward" = t
190                 then
191                         while read current_commit
192                         do
193                                 git rev-parse HEAD > "$rewritten"/$current_commit
194                         done <"$state_dir"/current-commit
195                         rm "$state_dir"/current-commit ||
196                         die "Cannot write current commit's replacement sha1"
197                 fi
198         fi
199
200         echo $sha1 >> "$state_dir"/current-commit
201
202         # rewrite parents; if none were rewritten, we can fast-forward.
203         new_parents=
204         pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
205         if test "$pend" = " "
206         then
207                 pend=" root"
208         fi
209         while [ "$pend" != "" ]
210         do
211                 p=$(expr "$pend" : ' \([^ ]*\)')
212                 pend="${pend# $p}"
213
214                 if test -f "$rewritten"/$p
215                 then
216                         new_p=$(cat "$rewritten"/$p)
217
218                         # If the todo reordered commits, and our parent is marked for
219                         # rewriting, but hasn't been gotten to yet, assume the user meant to
220                         # drop it on top of the current HEAD
221                         if test -z "$new_p"
222                         then
223                                 new_p=$(git rev-parse HEAD)
224                         fi
225
226                         test $p != $new_p && fast_forward=f
227                         case "$new_parents" in
228                         *$new_p*)
229                                 ;; # do nothing; that parent is already there
230                         *)
231                                 new_parents="$new_parents $new_p"
232                                 ;;
233                         esac
234                 else
235                         if test -f "$dropped"/$p
236                         then
237                                 fast_forward=f
238                                 replacement="$(cat "$dropped"/$p)"
239                                 test -z "$replacement" && replacement=root
240                                 pend=" $replacement$pend"
241                         else
242                                 new_parents="$new_parents $p"
243                         fi
244                 fi
245         done
246         case $fast_forward in
247         t)
248                 output warn "Fast-forward to $sha1"
249                 output git reset --hard $sha1 ||
250                         die "Cannot fast-forward to $sha1"
251                 ;;
252         f)
253                 first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
254
255                 if [ "$1" != "-n" ]
256                 then
257                         # detach HEAD to current parent
258                         output git checkout $first_parent 2> /dev/null ||
259                                 die "Cannot move HEAD to $first_parent"
260                 fi
261
262                 case "$new_parents" in
263                 ' '*' '*)
264                         test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
265
266                         # redo merge
267                         author_script_content=$(get_author_ident_from_commit $sha1)
268                         eval "$author_script_content"
269                         msg_content="$(commit_message $sha1)"
270                         # No point in merging the first parent, that's HEAD
271                         new_parents=${new_parents# $first_parent}
272                         if ! do_with_author output \
273                                 git merge --no-ff ${strategy:+-s $strategy} -m \
274                                         "$msg_content" $new_parents
275                         then
276                                 printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
277                                 die_with_patch $sha1 "Error redoing merge $sha1"
278                         fi
279                         echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
280                         ;;
281                 *)
282                         output git cherry-pick "$@" ||
283                                 die_with_patch $sha1 "Could not pick $sha1"
284                         ;;
285                 esac
286                 ;;
287         esac
288 }
289
290 nth_string () {
291         case "$1" in
292         *1[0-9]|*[04-9]) echo "$1"th;;
293         *1) echo "$1"st;;
294         *2) echo "$1"nd;;
295         *3) echo "$1"rd;;
296         esac
297 }
298
299 update_squash_messages () {
300         if test -f "$squash_msg"; then
301                 mv "$squash_msg" "$squash_msg".bak || exit
302                 count=$(($(sed -n \
303                         -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
304                         -e "q" < "$squash_msg".bak)+1))
305                 {
306                         echo "# This is a combination of $count commits."
307                         sed -e 1d -e '2,/^./{
308                                 /^$/d
309                         }' <"$squash_msg".bak
310                 } >"$squash_msg"
311         else
312                 commit_message HEAD > "$fixup_msg" || die "Cannot write $fixup_msg"
313                 count=2
314                 {
315                         echo "# This is a combination of 2 commits."
316                         echo "# The first commit's message is:"
317                         echo
318                         cat "$fixup_msg"
319                 } >"$squash_msg"
320         fi
321         case $1 in
322         squash)
323                 rm -f "$fixup_msg"
324                 echo
325                 echo "# This is the $(nth_string $count) commit message:"
326                 echo
327                 commit_message $2
328                 ;;
329         fixup)
330                 echo
331                 echo "# The $(nth_string $count) commit message will be skipped:"
332                 echo
333                 commit_message $2 | sed -e 's/^/#       /'
334                 ;;
335         esac >>"$squash_msg"
336 }
337
338 peek_next_command () {
339         sed -n -e "/^#/d" -e '/^$/d' -e "s/ .*//p" -e "q" < "$todo"
340 }
341
342 # A squash/fixup has failed.  Prepare the long version of the squash
343 # commit message, then die_with_patch.  This code path requires the
344 # user to edit the combined commit message for all commits that have
345 # been squashed/fixedup so far.  So also erase the old squash
346 # messages, effectively causing the combined commit to be used as the
347 # new basis for any further squash/fixups.  Args: sha1 rest
348 die_failed_squash() {
349         mv "$squash_msg" "$msg" || exit
350         rm -f "$fixup_msg"
351         cp "$msg" "$GIT_DIR"/MERGE_MSG || exit
352         warn
353         warn "Could not apply $1... $2"
354         die_with_patch $1 ""
355 }
356
357 flush_rewritten_pending() {
358         test -s "$rewritten_pending" || return
359         newsha1="$(git rev-parse HEAD^0)"
360         sed "s/$/ $newsha1/" < "$rewritten_pending" >> "$rewritten_list"
361         rm -f "$rewritten_pending"
362 }
363
364 record_in_rewritten() {
365         oldsha1="$(git rev-parse $1)"
366         echo "$oldsha1" >> "$rewritten_pending"
367
368         case "$(peek_next_command)" in
369         squash|s|fixup|f)
370                 ;;
371         *)
372                 flush_rewritten_pending
373                 ;;
374         esac
375 }
376
377 do_next () {
378         rm -f "$msg" "$author_script" "$amend" || exit
379         read -r command sha1 rest < "$todo"
380         case "$command" in
381         '#'*|''|noop)
382                 mark_action_done
383                 ;;
384         pick|p)
385                 comment_for_reflog pick
386
387                 mark_action_done
388                 pick_one $sha1 ||
389                         die_with_patch $sha1 "Could not apply $sha1... $rest"
390                 record_in_rewritten $sha1
391                 ;;
392         reword|r)
393                 comment_for_reflog reword
394
395                 mark_action_done
396                 pick_one $sha1 ||
397                         die_with_patch $sha1 "Could not apply $sha1... $rest"
398                 git commit --amend --no-post-rewrite
399                 record_in_rewritten $sha1
400                 ;;
401         edit|e)
402                 comment_for_reflog edit
403
404                 mark_action_done
405                 pick_one $sha1 ||
406                         die_with_patch $sha1 "Could not apply $sha1... $rest"
407                 echo "$sha1" > "$state_dir"/stopped-sha
408                 make_patch $sha1
409                 git rev-parse --verify HEAD > "$amend"
410                 warn "Stopped at $sha1... $rest"
411                 warn "You can amend the commit now, with"
412                 warn
413                 warn "  git commit --amend"
414                 warn
415                 warn "Once you are satisfied with your changes, run"
416                 warn
417                 warn "  git rebase --continue"
418                 warn
419                 exit 0
420                 ;;
421         squash|s|fixup|f)
422                 case "$command" in
423                 squash|s)
424                         squash_style=squash
425                         ;;
426                 fixup|f)
427                         squash_style=fixup
428                         ;;
429                 esac
430                 comment_for_reflog $squash_style
431
432                 test -f "$done" && has_action "$done" ||
433                         die "Cannot '$squash_style' without a previous commit"
434
435                 mark_action_done
436                 update_squash_messages $squash_style $sha1
437                 author_script_content=$(get_author_ident_from_commit HEAD)
438                 echo "$author_script_content" > "$author_script"
439                 eval "$author_script_content"
440                 output git reset --soft HEAD^
441                 pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
442                 case "$(peek_next_command)" in
443                 squash|s|fixup|f)
444                         # This is an intermediate commit; its message will only be
445                         # used in case of trouble.  So use the long version:
446                         do_with_author output git commit --no-verify -F "$squash_msg" ||
447                                 die_failed_squash $sha1 "$rest"
448                         ;;
449                 *)
450                         # This is the final command of this squash/fixup group
451                         if test -f "$fixup_msg"
452                         then
453                                 do_with_author git commit --no-verify -F "$fixup_msg" ||
454                                         die_failed_squash $sha1 "$rest"
455                         else
456                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
457                                 rm -f "$GIT_DIR"/MERGE_MSG
458                                 do_with_author git commit --no-verify -e ||
459                                         die_failed_squash $sha1 "$rest"
460                         fi
461                         rm -f "$squash_msg" "$fixup_msg"
462                         ;;
463                 esac
464                 record_in_rewritten $sha1
465                 ;;
466         x|"exec")
467                 read -r command rest < "$todo"
468                 mark_action_done
469                 printf 'Executing: %s\n' "$rest"
470                 # "exec" command doesn't take a sha1 in the todo-list.
471                 # => can't just use $sha1 here.
472                 git rev-parse --verify HEAD > "$state_dir"/stopped-sha
473                 ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
474                 status=$?
475                 if test "$status" -ne 0
476                 then
477                         warn "Execution failed: $rest"
478                         warn "You can fix the problem, and then run"
479                         warn
480                         warn "  git rebase --continue"
481                         warn
482                         exit "$status"
483                 fi
484                 # Run in subshell because require_clean_work_tree can die.
485                 if ! (require_clean_work_tree "rebase")
486                 then
487                         warn "Commit or stash your changes, and then run"
488                         warn
489                         warn "  git rebase --continue"
490                         warn
491                         exit 1
492                 fi
493                 ;;
494         *)
495                 warn "Unknown command: $command $sha1 $rest"
496                 if git rev-parse --verify -q "$sha1" >/dev/null
497                 then
498                         die_with_patch $sha1 "Please fix this in the file $todo."
499                 else
500                         die "Please fix this in the file $todo."
501                 fi
502                 ;;
503         esac
504         test -s "$todo" && return
505
506         comment_for_reflog finish &&
507         shortonto=$(git rev-parse --short $onto) &&
508         newhead=$(git rev-parse HEAD) &&
509         case $head_name in
510         refs/*)
511                 message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
512                 git update-ref -m "$message" $head_name $newhead $orig_head &&
513                 git symbolic-ref HEAD $head_name
514                 ;;
515         esac && {
516                 test ! -f "$state_dir"/verbose ||
517                         git diff-tree --stat $orig_head..HEAD
518         } &&
519         {
520                 test -s "$rewritten_list" &&
521                 git notes copy --for-rewrite=rebase < "$rewritten_list" ||
522                 true # we don't care if this copying failed
523         } &&
524         if test -x "$GIT_DIR"/hooks/post-rewrite &&
525                 test -s "$rewritten_list"; then
526                 "$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
527                 true # we don't care if this hook failed
528         fi &&
529         rm -rf "$state_dir" &&
530         git gc --auto &&
531         warn "Successfully rebased and updated $head_name."
532
533         exit
534 }
535
536 do_rest () {
537         while :
538         do
539                 do_next
540         done
541 }
542
543 # skip picking commits whose parents are unchanged
544 skip_unnecessary_picks () {
545         fd=3
546         while read -r command rest
547         do
548                 # fd=3 means we skip the command
549                 case "$fd,$command" in
550                 3,pick|3,p)
551                         # pick a commit whose parent is current $onto -> skip
552                         sha1=${rest%% *}
553                         case "$(git rev-parse --verify --quiet "$sha1"^)" in
554                         "$onto"*)
555                                 onto=$sha1
556                                 ;;
557                         *)
558                                 fd=1
559                                 ;;
560                         esac
561                         ;;
562                 3,#*|3,)
563                         # copy comments
564                         ;;
565                 *)
566                         fd=1
567                         ;;
568                 esac
569                 printf '%s\n' "$command${rest:+ }$rest" >&$fd
570         done <"$todo" >"$todo.new" 3>>"$done" &&
571         mv -f "$todo".new "$todo" &&
572         case "$(peek_next_command)" in
573         squash|s|fixup|f)
574                 record_in_rewritten "$onto"
575                 ;;
576         esac ||
577         die "Could not skip unnecessary pick commands"
578 }
579
580 # Rearrange the todo list that has both "pick sha1 msg" and
581 # "pick sha1 fixup!/squash! msg" appears in it so that the latter
582 # comes immediately after the former, and change "pick" to
583 # "fixup"/"squash".
584 rearrange_squash () {
585         # extract fixup!/squash! lines and resolve any referenced sha1's
586         while read -r pick sha1 message
587         do
588                 case "$message" in
589                 "squash! "*|"fixup! "*)
590                         action="${message%%!*}"
591                         rest="${message#*! }"
592                         echo "$sha1 $action $rest"
593                         # if it's a single word, try to resolve to a full sha1 and
594                         # emit a second copy. This allows us to match on both message
595                         # and on sha1 prefix
596                         if test "${rest#* }" = "$rest"; then
597                                 fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)"
598                                 if test -n "$fullsha"; then
599                                         # prefix the action to uniquely identify this line as
600                                         # intended for full sha1 match
601                                         echo "$sha1 +$action $fullsha"
602                                 fi
603                         fi
604                 esac
605         done >"$1.sq" <"$1"
606         test -s "$1.sq" || return
607
608         used=
609         while read -r pick sha1 message
610         do
611                 case " $used" in
612                 *" $sha1 "*) continue ;;
613                 esac
614                 printf '%s\n' "$pick $sha1 $message"
615                 used="$used$sha1 "
616                 while read -r squash action msg_content
617                 do
618                         case " $used" in
619                         *" $squash "*) continue ;;
620                         esac
621                         emit=0
622                         case "$action" in
623                         +*)
624                                 action="${action#+}"
625                                 # full sha1 prefix test
626                                 case "$msg_content" in "$sha1"*) emit=1;; esac ;;
627                         *)
628                                 # message prefix test
629                                 case "$message" in "$msg_content"*) emit=1;; esac ;;
630                         esac
631                         if test $emit = 1; then
632                                 printf '%s\n' "$action $squash $action! $msg_content"
633                                 used="$used$squash "
634                         fi
635                 done <"$1.sq"
636         done >"$1.rearranged" <"$1"
637         cat "$1.rearranged" >"$1"
638         rm -f "$1.sq" "$1.rearranged"
639 }
640
641 case "$action" in
642 continue)
643         # do we have anything to commit?
644         if git diff-index --cached --quiet --ignore-submodules HEAD --
645         then
646                 : Nothing to commit -- skip this
647         else
648                 . "$author_script" ||
649                         die "Cannot find the author identity"
650                 current_head=
651                 if test -f "$amend"
652                 then
653                         current_head=$(git rev-parse --verify HEAD)
654                         test "$current_head" = $(cat "$amend") ||
655                         die "\
656 You have uncommitted changes in your working tree. Please, commit them
657 first and then run 'git rebase --continue' again."
658                         git reset --soft HEAD^ ||
659                         die "Cannot rewind the HEAD"
660                 fi
661                 do_with_author git commit --no-verify -F "$msg" -e || {
662                         test -n "$current_head" && git reset --soft $current_head
663                         die "Could not commit staged changes."
664                 }
665         fi
666
667         record_in_rewritten "$(cat "$state_dir"/stopped-sha)"
668
669         require_clean_work_tree "rebase"
670         do_rest
671         ;;
672 skip)
673         git rerere clear
674
675         do_rest
676         ;;
677 esac
678
679 git var GIT_COMMITTER_IDENT >/dev/null ||
680         die "You need to set your committer info first"
681
682 comment_for_reflog start
683
684 if test ! -z "$switch_to"
685 then
686         output git checkout "$switch_to" -- ||
687                 die "Could not checkout $switch_to"
688 fi
689
690 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
691 mkdir "$state_dir" || die "Could not create temporary $state_dir"
692
693 : > "$state_dir"/interactive || die "Could not mark as interactive"
694 write_basic_state
695 if test t = "$preserve_merges"
696 then
697         if test -z "$rebase_root"
698         then
699                 mkdir "$rewritten" &&
700                 for c in $(git merge-base --all $orig_head $upstream)
701                 do
702                         echo $onto > "$rewritten"/$c ||
703                                 die "Could not init rewritten commits"
704                 done
705         else
706                 mkdir "$rewritten" &&
707                 echo $onto > "$rewritten"/root ||
708                         die "Could not init rewritten commits"
709         fi
710         # No cherry-pick because our first pass is to determine
711         # parents to rewrite and skipping dropped commits would
712         # prematurely end our probe
713         merges_option=
714         first_after_upstream="$(git rev-list --reverse --first-parent $upstream..$orig_head | head -n 1)"
715 else
716         merges_option="--no-merges --cherry-pick"
717 fi
718
719 shorthead=$(git rev-parse --short $orig_head)
720 shortonto=$(git rev-parse --short $onto)
721 if test -z "$rebase_root"
722         # this is now equivalent to ! -z "$upstream"
723 then
724         shortupstream=$(git rev-parse --short $upstream)
725         revisions=$upstream...$orig_head
726         shortrevisions=$shortupstream..$shorthead
727 else
728         revisions=$onto...$orig_head
729         shortrevisions=$shorthead
730 fi
731 git rev-list $merges_option --pretty=oneline --abbrev-commit \
732         --abbrev=7 --reverse --left-right --topo-order \
733         $revisions | \
734         sed -n "s/^>//p" |
735 while read -r shortsha1 rest
736 do
737         if test t != "$preserve_merges"
738         then
739                 printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
740         else
741                 sha1=$(git rev-parse $shortsha1)
742                 if test -z "$rebase_root"
743                 then
744                         preserve=t
745                         for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
746                         do
747                                 if test -f "$rewritten"/$p -a \( $p != $onto -o $sha1 = $first_after_upstream \)
748                                 then
749                                         preserve=f
750                                 fi
751                         done
752                 else
753                         preserve=f
754                 fi
755                 if test f = "$preserve"
756                 then
757                         touch "$rewritten"/$sha1
758                         printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
759                 fi
760         fi
761 done
762
763 # Watch for commits that been dropped by --cherry-pick
764 if test t = "$preserve_merges"
765 then
766         mkdir "$dropped"
767         # Save all non-cherry-picked changes
768         git rev-list $revisions --left-right --cherry-pick | \
769                 sed -n "s/^>//p" > "$state_dir"/not-cherry-picks
770         # Now all commits and note which ones are missing in
771         # not-cherry-picks and hence being dropped
772         git rev-list $revisions |
773         while read rev
774         do
775                 if test -f "$rewritten"/$rev -a "$(sane_grep "$rev" "$state_dir"/not-cherry-picks)" = ""
776                 then
777                         # Use -f2 because if rev-list is telling us this commit is
778                         # not worthwhile, we don't want to track its multiple heads,
779                         # just the history of its first-parent for others that will
780                         # be rebasing on top of it
781                         git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$dropped"/$rev
782                         short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
783                         sane_grep -v "^[a-z][a-z]* $short" <"$todo" > "${todo}2" ; mv "${todo}2" "$todo"
784                         rm "$rewritten"/$rev
785                 fi
786         done
787 fi
788
789 test -s "$todo" || echo noop >> "$todo"
790 test -n "$autosquash" && rearrange_squash "$todo"
791 cat >> "$todo" << EOF
792
793 # Rebase $shortrevisions onto $shortonto
794 #
795 # Commands:
796 #  p, pick = use commit
797 #  r, reword = use commit, but edit the commit message
798 #  e, edit = use commit, but stop for amending
799 #  s, squash = use commit, but meld into previous commit
800 #  f, fixup = like "squash", but discard this commit's log message
801 #  x, exec = run command (the rest of the line) using shell
802 #
803 # If you remove a line here THAT COMMIT WILL BE LOST.
804 # However, if you remove everything, the rebase will be aborted.
805 #
806 EOF
807
808 has_action "$todo" ||
809         die_abort "Nothing to do"
810
811 cp "$todo" "$todo".backup
812 git_editor "$todo" ||
813         die_abort "Could not execute editor"
814
815 has_action "$todo" ||
816         die_abort "Nothing to do"
817
818 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
819
820 output git checkout $onto || die_abort "could not detach HEAD"
821 git update-ref ORIG_HEAD $orig_head
822 do_rest