Merge branch 'jk/credentials'
[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 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 $2
159 }
160
161 die_abort () {
162         rm -rf "$state_dir"
163         die "$1"
164 }
165
166 has_action () {
167         sane_grep '^[^#]' "$1" >/dev/null
168 }
169
170 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
171 # GIT_AUTHOR_DATE exported from the current environment.
172 do_with_author () {
173         (
174                 export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
175                 "$@"
176         )
177 }
178
179 git_sequence_editor () {
180         if test -z "$GIT_SEQUENCE_EDITOR"
181         then
182                 GIT_SEQUENCE_EDITOR="$(git config sequence.editor)"
183                 if [ -z "$GIT_SEQUENCE_EDITOR" ]
184                 then
185                         GIT_SEQUENCE_EDITOR="$(git var GIT_EDITOR)" || return $?
186                 fi
187         fi
188
189         eval "$GIT_SEQUENCE_EDITOR" '"$@"'
190 }
191
192 pick_one () {
193         ff=--ff
194         case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
195         case "$force_rebase" in '') ;; ?*) ff= ;; esac
196         output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
197         test -d "$rewritten" &&
198                 pick_one_preserving_merges "$@" && return
199         output git cherry-pick $ff "$@"
200 }
201
202 pick_one_preserving_merges () {
203         fast_forward=t
204         case "$1" in
205         -n)
206                 fast_forward=f
207                 sha1=$2
208                 ;;
209         *)
210                 sha1=$1
211                 ;;
212         esac
213         sha1=$(git rev-parse $sha1)
214
215         if test -f "$state_dir"/current-commit
216         then
217                 if test "$fast_forward" = t
218                 then
219                         while read current_commit
220                         do
221                                 git rev-parse HEAD > "$rewritten"/$current_commit
222                         done <"$state_dir"/current-commit
223                         rm "$state_dir"/current-commit ||
224                         die "Cannot write current commit's replacement sha1"
225                 fi
226         fi
227
228         echo $sha1 >> "$state_dir"/current-commit
229
230         # rewrite parents; if none were rewritten, we can fast-forward.
231         new_parents=
232         pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
233         if test "$pend" = " "
234         then
235                 pend=" root"
236         fi
237         while [ "$pend" != "" ]
238         do
239                 p=$(expr "$pend" : ' \([^ ]*\)')
240                 pend="${pend# $p}"
241
242                 if test -f "$rewritten"/$p
243                 then
244                         new_p=$(cat "$rewritten"/$p)
245
246                         # If the todo reordered commits, and our parent is marked for
247                         # rewriting, but hasn't been gotten to yet, assume the user meant to
248                         # drop it on top of the current HEAD
249                         if test -z "$new_p"
250                         then
251                                 new_p=$(git rev-parse HEAD)
252                         fi
253
254                         test $p != $new_p && fast_forward=f
255                         case "$new_parents" in
256                         *$new_p*)
257                                 ;; # do nothing; that parent is already there
258                         *)
259                                 new_parents="$new_parents $new_p"
260                                 ;;
261                         esac
262                 else
263                         if test -f "$dropped"/$p
264                         then
265                                 fast_forward=f
266                                 replacement="$(cat "$dropped"/$p)"
267                                 test -z "$replacement" && replacement=root
268                                 pend=" $replacement$pend"
269                         else
270                                 new_parents="$new_parents $p"
271                         fi
272                 fi
273         done
274         case $fast_forward in
275         t)
276                 output warn "Fast-forward to $sha1"
277                 output git reset --hard $sha1 ||
278                         die "Cannot fast-forward to $sha1"
279                 ;;
280         f)
281                 first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
282
283                 if [ "$1" != "-n" ]
284                 then
285                         # detach HEAD to current parent
286                         output git checkout $first_parent 2> /dev/null ||
287                                 die "Cannot move HEAD to $first_parent"
288                 fi
289
290                 case "$new_parents" in
291                 ' '*' '*)
292                         test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
293
294                         # redo merge
295                         author_script_content=$(get_author_ident_from_commit $sha1)
296                         eval "$author_script_content"
297                         msg_content="$(commit_message $sha1)"
298                         # No point in merging the first parent, that's HEAD
299                         new_parents=${new_parents# $first_parent}
300                         if ! do_with_author output \
301                                 git merge --no-ff ${strategy:+-s $strategy} -m \
302                                         "$msg_content" $new_parents
303                         then
304                                 printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
305                                 die_with_patch $sha1 "Error redoing merge $sha1"
306                         fi
307                         echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
308                         ;;
309                 *)
310                         output git cherry-pick "$@" ||
311                                 die_with_patch $sha1 "Could not pick $sha1"
312                         ;;
313                 esac
314                 ;;
315         esac
316 }
317
318 nth_string () {
319         case "$1" in
320         *1[0-9]|*[04-9]) echo "$1"th;;
321         *1) echo "$1"st;;
322         *2) echo "$1"nd;;
323         *3) echo "$1"rd;;
324         esac
325 }
326
327 update_squash_messages () {
328         if test -f "$squash_msg"; then
329                 mv "$squash_msg" "$squash_msg".bak || exit
330                 count=$(($(sed -n \
331                         -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
332                         -e "q" < "$squash_msg".bak)+1))
333                 {
334                         echo "# This is a combination of $count commits."
335                         sed -e 1d -e '2,/^./{
336                                 /^$/d
337                         }' <"$squash_msg".bak
338                 } >"$squash_msg"
339         else
340                 commit_message HEAD > "$fixup_msg" || die "Cannot write $fixup_msg"
341                 count=2
342                 {
343                         echo "# This is a combination of 2 commits."
344                         echo "# The first commit's message is:"
345                         echo
346                         cat "$fixup_msg"
347                 } >"$squash_msg"
348         fi
349         case $1 in
350         squash)
351                 rm -f "$fixup_msg"
352                 echo
353                 echo "# This is the $(nth_string $count) commit message:"
354                 echo
355                 commit_message $2
356                 ;;
357         fixup)
358                 echo
359                 echo "# The $(nth_string $count) commit message will be skipped:"
360                 echo
361                 commit_message $2 | sed -e 's/^/#       /'
362                 ;;
363         esac >>"$squash_msg"
364 }
365
366 peek_next_command () {
367         sed -n -e "/^#/d" -e '/^$/d' -e "s/ .*//p" -e "q" < "$todo"
368 }
369
370 # A squash/fixup has failed.  Prepare the long version of the squash
371 # commit message, then die_with_patch.  This code path requires the
372 # user to edit the combined commit message for all commits that have
373 # been squashed/fixedup so far.  So also erase the old squash
374 # messages, effectively causing the combined commit to be used as the
375 # new basis for any further squash/fixups.  Args: sha1 rest
376 die_failed_squash() {
377         mv "$squash_msg" "$msg" || exit
378         rm -f "$fixup_msg"
379         cp "$msg" "$GIT_DIR"/MERGE_MSG || exit
380         warn
381         warn "Could not apply $1... $2"
382         die_with_patch $1 ""
383 }
384
385 flush_rewritten_pending() {
386         test -s "$rewritten_pending" || return
387         newsha1="$(git rev-parse HEAD^0)"
388         sed "s/$/ $newsha1/" < "$rewritten_pending" >> "$rewritten_list"
389         rm -f "$rewritten_pending"
390 }
391
392 record_in_rewritten() {
393         oldsha1="$(git rev-parse $1)"
394         echo "$oldsha1" >> "$rewritten_pending"
395
396         case "$(peek_next_command)" in
397         squash|s|fixup|f)
398                 ;;
399         *)
400                 flush_rewritten_pending
401                 ;;
402         esac
403 }
404
405 do_next () {
406         rm -f "$msg" "$author_script" "$amend" || exit
407         read -r command sha1 rest < "$todo"
408         case "$command" in
409         '#'*|''|noop)
410                 mark_action_done
411                 ;;
412         pick|p)
413                 comment_for_reflog pick
414
415                 mark_action_done
416                 pick_one $sha1 ||
417                         die_with_patch $sha1 "Could not apply $sha1... $rest"
418                 record_in_rewritten $sha1
419                 ;;
420         reword|r)
421                 comment_for_reflog reword
422
423                 mark_action_done
424                 pick_one $sha1 ||
425                         die_with_patch $sha1 "Could not apply $sha1... $rest"
426                 git commit --amend --no-post-rewrite || {
427                         warn "Could not amend commit after successfully picking $sha1... $rest"
428                         warn "This is most likely due to an empty commit message, or the pre-commit hook"
429                         warn "failed. If the pre-commit hook failed, you may need to resolve the issue before"
430                         warn "you are able to reword the commit."
431                         exit_with_patch $sha1 1
432                 }
433                 record_in_rewritten $sha1
434                 ;;
435         edit|e)
436                 comment_for_reflog edit
437
438                 mark_action_done
439                 pick_one $sha1 ||
440                         die_with_patch $sha1 "Could not apply $sha1... $rest"
441                 warn "Stopped at $sha1... $rest"
442                 exit_with_patch $sha1 0
443                 ;;
444         squash|s|fixup|f)
445                 case "$command" in
446                 squash|s)
447                         squash_style=squash
448                         ;;
449                 fixup|f)
450                         squash_style=fixup
451                         ;;
452                 esac
453                 comment_for_reflog $squash_style
454
455                 test -f "$done" && has_action "$done" ||
456                         die "Cannot '$squash_style' without a previous commit"
457
458                 mark_action_done
459                 update_squash_messages $squash_style $sha1
460                 author_script_content=$(get_author_ident_from_commit HEAD)
461                 echo "$author_script_content" > "$author_script"
462                 eval "$author_script_content"
463                 output git reset --soft HEAD^
464                 pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
465                 case "$(peek_next_command)" in
466                 squash|s|fixup|f)
467                         # This is an intermediate commit; its message will only be
468                         # used in case of trouble.  So use the long version:
469                         do_with_author output git commit --no-verify -F "$squash_msg" ||
470                                 die_failed_squash $sha1 "$rest"
471                         ;;
472                 *)
473                         # This is the final command of this squash/fixup group
474                         if test -f "$fixup_msg"
475                         then
476                                 do_with_author git commit --no-verify -F "$fixup_msg" ||
477                                         die_failed_squash $sha1 "$rest"
478                         else
479                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
480                                 rm -f "$GIT_DIR"/MERGE_MSG
481                                 do_with_author git commit --no-verify -e ||
482                                         die_failed_squash $sha1 "$rest"
483                         fi
484                         rm -f "$squash_msg" "$fixup_msg"
485                         ;;
486                 esac
487                 record_in_rewritten $sha1
488                 ;;
489         x|"exec")
490                 read -r command rest < "$todo"
491                 mark_action_done
492                 printf 'Executing: %s\n' "$rest"
493                 # "exec" command doesn't take a sha1 in the todo-list.
494                 # => can't just use $sha1 here.
495                 git rev-parse --verify HEAD > "$state_dir"/stopped-sha
496                 ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
497                 status=$?
498                 # Run in subshell because require_clean_work_tree can die.
499                 dirty=f
500                 (require_clean_work_tree "rebase" 2>/dev/null) || dirty=t
501                 if test "$status" -ne 0
502                 then
503                         warn "Execution failed: $rest"
504                         test "$dirty" = f ||
505                         warn "and made changes to the index and/or the working tree"
506
507                         warn "You can fix the problem, and then run"
508                         warn
509                         warn "  git rebase --continue"
510                         warn
511                         exit "$status"
512                 elif test "$dirty" = t
513                 then
514                         warn "Execution succeeded: $rest"
515                         warn "but left changes to the index and/or the working tree"
516                         warn "Commit or stash your changes, and then run"
517                         warn
518                         warn "  git rebase --continue"
519                         warn
520                         exit 1
521                 fi
522                 ;;
523         *)
524                 warn "Unknown command: $command $sha1 $rest"
525                 if git rev-parse --verify -q "$sha1" >/dev/null
526                 then
527                         die_with_patch $sha1 "Please fix this in the file $todo."
528                 else
529                         die "Please fix this in the file $todo."
530                 fi
531                 ;;
532         esac
533         test -s "$todo" && return
534
535         comment_for_reflog finish &&
536         shortonto=$(git rev-parse --short $onto) &&
537         newhead=$(git rev-parse HEAD) &&
538         case $head_name in
539         refs/*)
540                 message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
541                 git update-ref -m "$message" $head_name $newhead $orig_head &&
542                 git symbolic-ref \
543                   -m "$GIT_REFLOG_ACTION: returning to $head_name" \
544                   HEAD $head_name
545                 ;;
546         esac && {
547                 test ! -f "$state_dir"/verbose ||
548                         git diff-tree --stat $orig_head..HEAD
549         } &&
550         {
551                 test -s "$rewritten_list" &&
552                 git notes copy --for-rewrite=rebase < "$rewritten_list" ||
553                 true # we don't care if this copying failed
554         } &&
555         if test -x "$GIT_DIR"/hooks/post-rewrite &&
556                 test -s "$rewritten_list"; then
557                 "$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
558                 true # we don't care if this hook failed
559         fi &&
560         rm -rf "$state_dir" &&
561         git gc --auto &&
562         warn "Successfully rebased and updated $head_name."
563
564         exit
565 }
566
567 do_rest () {
568         while :
569         do
570                 do_next
571         done
572 }
573
574 # skip picking commits whose parents are unchanged
575 skip_unnecessary_picks () {
576         fd=3
577         while read -r command rest
578         do
579                 # fd=3 means we skip the command
580                 case "$fd,$command" in
581                 3,pick|3,p)
582                         # pick a commit whose parent is current $onto -> skip
583                         sha1=${rest%% *}
584                         case "$(git rev-parse --verify --quiet "$sha1"^)" in
585                         "$onto"*)
586                                 onto=$sha1
587                                 ;;
588                         *)
589                                 fd=1
590                                 ;;
591                         esac
592                         ;;
593                 3,#*|3,)
594                         # copy comments
595                         ;;
596                 *)
597                         fd=1
598                         ;;
599                 esac
600                 printf '%s\n' "$command${rest:+ }$rest" >&$fd
601         done <"$todo" >"$todo.new" 3>>"$done" &&
602         mv -f "$todo".new "$todo" &&
603         case "$(peek_next_command)" in
604         squash|s|fixup|f)
605                 record_in_rewritten "$onto"
606                 ;;
607         esac ||
608         die "Could not skip unnecessary pick commands"
609 }
610
611 # Rearrange the todo list that has both "pick sha1 msg" and
612 # "pick sha1 fixup!/squash! msg" appears in it so that the latter
613 # comes immediately after the former, and change "pick" to
614 # "fixup"/"squash".
615 rearrange_squash () {
616         # extract fixup!/squash! lines and resolve any referenced sha1's
617         while read -r pick sha1 message
618         do
619                 case "$message" in
620                 "squash! "*|"fixup! "*)
621                         action="${message%%!*}"
622                         rest="${message#*! }"
623                         echo "$sha1 $action $rest"
624                         # if it's a single word, try to resolve to a full sha1 and
625                         # emit a second copy. This allows us to match on both message
626                         # and on sha1 prefix
627                         if test "${rest#* }" = "$rest"; then
628                                 fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)"
629                                 if test -n "$fullsha"; then
630                                         # prefix the action to uniquely identify this line as
631                                         # intended for full sha1 match
632                                         echo "$sha1 +$action $fullsha"
633                                 fi
634                         fi
635                 esac
636         done >"$1.sq" <"$1"
637         test -s "$1.sq" || return
638
639         used=
640         while read -r pick sha1 message
641         do
642                 case " $used" in
643                 *" $sha1 "*) continue ;;
644                 esac
645                 printf '%s\n' "$pick $sha1 $message"
646                 used="$used$sha1 "
647                 while read -r squash action msg_content
648                 do
649                         case " $used" in
650                         *" $squash "*) continue ;;
651                         esac
652                         emit=0
653                         case "$action" in
654                         +*)
655                                 action="${action#+}"
656                                 # full sha1 prefix test
657                                 case "$msg_content" in "$sha1"*) emit=1;; esac ;;
658                         *)
659                                 # message prefix test
660                                 case "$message" in "$msg_content"*) emit=1;; esac ;;
661                         esac
662                         if test $emit = 1; then
663                                 printf '%s\n' "$action $squash $action! $msg_content"
664                                 used="$used$squash "
665                         fi
666                 done <"$1.sq"
667         done >"$1.rearranged" <"$1"
668         cat "$1.rearranged" >"$1"
669         rm -f "$1.sq" "$1.rearranged"
670 }
671
672 case "$action" in
673 continue)
674         # do we have anything to commit?
675         if git diff-index --cached --quiet --ignore-submodules HEAD --
676         then
677                 : Nothing to commit -- skip this
678         else
679                 if ! test -f "$author_script"
680                 then
681                         die "You have staged changes in your working tree. If these changes are meant to be
682 squashed into the previous commit, run:
683
684   git commit --amend
685
686 If they are meant to go into a new commit, run:
687
688   git commit
689
690 In both case, once you're done, continue with:
691
692   git rebase --continue
693 "
694                 fi
695                 . "$author_script" ||
696                         die "Error trying to find the author identity to amend commit"
697                 current_head=
698                 if test -f "$amend"
699                 then
700                         current_head=$(git rev-parse --verify HEAD)
701                         test "$current_head" = $(cat "$amend") ||
702                         die "\
703 You have uncommitted changes in your working tree. Please, commit them
704 first and then run 'git rebase --continue' again."
705                         git reset --soft HEAD^ ||
706                         die "Cannot rewind the HEAD"
707                 fi
708                 do_with_author git commit --no-verify -F "$msg" -e || {
709                         test -n "$current_head" && git reset --soft $current_head
710                         die "Could not commit staged changes."
711                 }
712         fi
713
714         record_in_rewritten "$(cat "$state_dir"/stopped-sha)"
715
716         require_clean_work_tree "rebase"
717         do_rest
718         ;;
719 skip)
720         git rerere clear
721
722         do_rest
723         ;;
724 esac
725
726 git var GIT_COMMITTER_IDENT >/dev/null ||
727         die "You need to set your committer info first"
728
729 comment_for_reflog start
730
731 if test ! -z "$switch_to"
732 then
733         output git checkout "$switch_to" -- ||
734                 die "Could not checkout $switch_to"
735 fi
736
737 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
738 mkdir "$state_dir" || die "Could not create temporary $state_dir"
739
740 : > "$state_dir"/interactive || die "Could not mark as interactive"
741 write_basic_state
742 if test t = "$preserve_merges"
743 then
744         if test -z "$rebase_root"
745         then
746                 mkdir "$rewritten" &&
747                 for c in $(git merge-base --all $orig_head $upstream)
748                 do
749                         echo $onto > "$rewritten"/$c ||
750                                 die "Could not init rewritten commits"
751                 done
752         else
753                 mkdir "$rewritten" &&
754                 echo $onto > "$rewritten"/root ||
755                         die "Could not init rewritten commits"
756         fi
757         # No cherry-pick because our first pass is to determine
758         # parents to rewrite and skipping dropped commits would
759         # prematurely end our probe
760         merges_option=
761 else
762         merges_option="--no-merges --cherry-pick"
763 fi
764
765 shorthead=$(git rev-parse --short $orig_head)
766 shortonto=$(git rev-parse --short $onto)
767 if test -z "$rebase_root"
768         # this is now equivalent to ! -z "$upstream"
769 then
770         shortupstream=$(git rev-parse --short $upstream)
771         revisions=$upstream...$orig_head
772         shortrevisions=$shortupstream..$shorthead
773 else
774         revisions=$onto...$orig_head
775         shortrevisions=$shorthead
776 fi
777 git rev-list $merges_option --pretty=oneline --abbrev-commit \
778         --abbrev=7 --reverse --left-right --topo-order \
779         $revisions | \
780         sed -n "s/^>//p" |
781 while read -r shortsha1 rest
782 do
783         if test t != "$preserve_merges"
784         then
785                 printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
786         else
787                 sha1=$(git rev-parse $shortsha1)
788                 if test -z "$rebase_root"
789                 then
790                         preserve=t
791                         for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
792                         do
793                                 if test -f "$rewritten"/$p
794                                 then
795                                         preserve=f
796                                 fi
797                         done
798                 else
799                         preserve=f
800                 fi
801                 if test f = "$preserve"
802                 then
803                         touch "$rewritten"/$sha1
804                         printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
805                 fi
806         fi
807 done
808
809 # Watch for commits that been dropped by --cherry-pick
810 if test t = "$preserve_merges"
811 then
812         mkdir "$dropped"
813         # Save all non-cherry-picked changes
814         git rev-list $revisions --left-right --cherry-pick | \
815                 sed -n "s/^>//p" > "$state_dir"/not-cherry-picks
816         # Now all commits and note which ones are missing in
817         # not-cherry-picks and hence being dropped
818         git rev-list $revisions |
819         while read rev
820         do
821                 if test -f "$rewritten"/$rev -a "$(sane_grep "$rev" "$state_dir"/not-cherry-picks)" = ""
822                 then
823                         # Use -f2 because if rev-list is telling us this commit is
824                         # not worthwhile, we don't want to track its multiple heads,
825                         # just the history of its first-parent for others that will
826                         # be rebasing on top of it
827                         git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$dropped"/$rev
828                         short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
829                         sane_grep -v "^[a-z][a-z]* $short" <"$todo" > "${todo}2" ; mv "${todo}2" "$todo"
830                         rm "$rewritten"/$rev
831                 fi
832         done
833 fi
834
835 test -s "$todo" || echo noop >> "$todo"
836 test -n "$autosquash" && rearrange_squash "$todo"
837 cat >> "$todo" << EOF
838
839 # Rebase $shortrevisions onto $shortonto
840 #
841 # Commands:
842 #  p, pick = use commit
843 #  r, reword = use commit, but edit the commit message
844 #  e, edit = use commit, but stop for amending
845 #  s, squash = use commit, but meld into previous commit
846 #  f, fixup = like "squash", but discard this commit's log message
847 #  x, exec = run command (the rest of the line) using shell
848 #
849 # If you remove a line here THAT COMMIT WILL BE LOST.
850 # However, if you remove everything, the rebase will be aborted.
851 #
852 EOF
853
854 has_action "$todo" ||
855         die_abort "Nothing to do"
856
857 cp "$todo" "$todo".backup
858 git_sequence_editor "$todo" ||
859         die_abort "Could not execute editor"
860
861 has_action "$todo" ||
862         die_abort "Nothing to do"
863
864 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
865
866 output git checkout $onto || die_abort "could not detach HEAD"
867 git update-ref ORIG_HEAD $orig_head
868 do_rest