summaryrefslogtreecommitdiff
path: root/git-rebase--interactive.sh
blob: 1499a67bba6bf9372d38acf890151bd802773953 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
#!/bin/sh
#
# Copyright (c) 2006 Johannes E. Schindelin
 
# SHORT DESCRIPTION
#
# This script makes it easy to fix up commits in the middle of a series,
# and rearrange commits.
#
# The original idea comes from Eric W. Biederman, in
# http://article.gmane.org/gmane.comp.version-control.git/22407
 
OPTIONS_KEEPDASHDASH=
OPTIONS_SPEC="\
git-rebase [-i] [options] [--] <upstream> [<branch>]
git-rebase [-i] (--continue | --abort | --skip)
--
 Available options are
v,verbose          display a diffstat of what changed upstream
onto=              rebase onto given branch instead of upstream
p,preserve-merges  try to recreate merges instead of ignoring them
s,strategy=        use the given merge strategy
m,merge            always used (no-op)
i,interactive      always used (no-op)
 Actions:
continue           continue rebasing process
abort              abort rebasing process and restore original branch
skip               skip current patch and continue rebasing process
no-verify          override pre-rebase hook from stopping the operation
root               rebase all reachable commmits up to the root(s)
"
 
. git-sh-setup
require_work_tree
 
DOTEST="$GIT_DIR/rebase-merge"
 
# The file containing rebase commands, comments, and empty lines.
# This file is created by "git rebase -i" then edited by the user.  As
# the lines are processed, they are removed from the front of this
# file and written to the tail of $DONE.
TODO="$DOTEST"/git-rebase-todo
 
# The rebase command lines that have already been processed.  A line
# is moved here when it is first handled, before any associated user
# actions.
DONE="$DOTEST"/done
 
# The commit message that is planned to be used for any changes that
# need to be committed following a user interaction.
MSG="$DOTEST"/message
 
# The file into which is accumulated the suggested commit message for
# squash/fixup commands.  When the first of a series of squash/fixups
# is seen, the file is created and the commit message from the
# previous commit and from the first squash/fixup commit are written
# to it.  The commit message for each subsequent squash/fixup commit
# is appended to the file as it is processed.
#
# The first line of the file is of the form
#     # This is a combination of $COUNT commits.
# where $COUNT is the number of commits whose messages have been
# written to the file so far (including the initial "pick" commit).
# Each time that a commit message is processed, this line is read and
# updated.  It is deleted just before the combined commit is made.
SQUASH_MSG="$DOTEST"/message-squash
 
# $REWRITTEN is the name of a directory containing files for each
# commit that is reachable by at least one merge base of $HEAD and
# $UPSTREAM. They are not necessarily rewritten, but their children
# might be.  This ensures that commits on merged, but otherwise
# unrelated side branches are left alone. (Think "X" in the man page's
# example.)
REWRITTEN="$DOTEST"/rewritten
 
DROPPED="$DOTEST"/dropped
 
# A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
# GIT_AUTHOR_DATE that will be used for the commit that is currently
# being rebased.
AUTHOR_SCRIPT="$DOTEST"/author-script
 
# When an "edit" rebase command is being processed, the SHA1 of the
# commit to be edited is recorded in this file.  When "git rebase
# --continue" is executed, if there are any staged changes then they
# will be amended to the HEAD commit, but only provided the HEAD
# commit is still the commit to be edited.  When any other rebase
# command is processed, this file is deleted.
AMEND="$DOTEST"/amend
 
PRESERVE_MERGES=
STRATEGY=
ONTO=
VERBOSE=
OK_TO_SKIP_PRE_REBASE=
REBASE_ROOT=
 
GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
mark the corrected paths with 'git add <paths>', and
run 'git rebase --continue'"
export GIT_CHERRY_PICK_HELP
 
warn () {
	echo "$*" >&2
}
 
output () {
	case "$VERBOSE" in
	'')
		output=$("$@" 2>&1 )
		status=$?
		test $status != 0 && printf "%s\n" "$output"
		return $status
		;;
	*)
		"$@"
		;;
	esac
}
 
# Output the commit message for the specified commit.
commit_message () {
	git cat-file commit "$1" | sed "1,/^$/d"
}
 
run_pre_rebase_hook () {
	if test -z "$OK_TO_SKIP_PRE_REBASE" &&
	   test -x "$GIT_DIR/hooks/pre-rebase"
	then
		"$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
			echo >&2 "The pre-rebase hook refused to rebase."
			exit 1
		}
	fi
}
 
require_clean_work_tree () {
	# test if working tree is dirty
	git rev-parse --verify HEAD > /dev/null &&
	git update-index --ignore-submodules --refresh &&
	git diff-files --quiet --ignore-submodules &&
	git diff-index --cached --quiet HEAD --ignore-submodules -- ||
	die "Working tree is dirty"
}
 
ORIG_REFLOG_ACTION="$GIT_REFLOG_ACTION"
 
comment_for_reflog () {
	case "$ORIG_REFLOG_ACTION" in
	''|rebase*)
		GIT_REFLOG_ACTION="rebase -i ($1)"
		export GIT_REFLOG_ACTION
		;;
	esac
}
 
last_count=
mark_action_done () {
	sed -e 1q < "$TODO" >> "$DONE"
	sed -e 1d < "$TODO" >> "$TODO".new
	mv -f "$TODO".new "$TODO"
	count=$(sane_grep -c '^[^#]' < "$DONE")
	total=$(($count+$(sane_grep -c '^[^#]' < "$TODO")))
	if test "$last_count" != "$count"
	then
		last_count=$count
		printf "Rebasing (%d/%d)\r" $count $total
		test -z "$VERBOSE" || echo
	fi
}
 
make_patch () {
	sha1_and_parents="$(git rev-list --parents -1 "$1")"
	case "$sha1_and_parents" in
	?*' '?*' '?*)
		git diff --cc $sha1_and_parents
		;;
	?*' '?*)
		git diff-tree -p "$1^!"
		;;
	*)
		echo "Root commit"
		;;
	esac > "$DOTEST"/patch
	test -f "$MSG" ||
		commit_message "$1" > "$MSG"
	test -f "$AUTHOR_SCRIPT" ||
		get_author_ident_from_commit "$1" > "$AUTHOR_SCRIPT"
}
 
die_with_patch () {
	make_patch "$1"
	git rerere
	die "$2"
}
 
die_abort () {
	rm -rf "$DOTEST"
	die "$1"
}
 
has_action () {
	sane_grep '^[^#]' "$1" >/dev/null
}
 
pick_one () {
	no_ff=
	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
	output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
	test -d "$REWRITTEN" &&
		pick_one_preserving_merges "$@" && return
	if test -n "$REBASE_ROOT"
	then
		output git cherry-pick "$@"
		return
	fi
	parent_sha1=$(git rev-parse --verify $sha1^) ||
		die "Could not get the parent of $sha1"
	current_sha1=$(git rev-parse --verify HEAD)
	if test -z "$no_ff" -a "$current_sha1" = "$parent_sha1"
	then
		output git reset --hard $sha1
		output warn Fast-forward to $(git rev-parse --short $sha1)
	else
		output git cherry-pick "$@"
	fi
}
 
pick_one_preserving_merges () {
	fast_forward=t
	case "$1" in
	-n)
		fast_forward=f
		sha1=$2
		;;
	*)
		sha1=$1
		;;
	esac
	sha1=$(git rev-parse $sha1)
 
	if test -f "$DOTEST"/current-commit
	then
		if test "$fast_forward" = t
		then
			cat "$DOTEST"/current-commit | while read current_commit
			do
				git rev-parse HEAD > "$REWRITTEN"/$current_commit
			done
			rm "$DOTEST"/current-commit ||
			die "Cannot write current commit's replacement sha1"
		fi
	fi
 
	echo $sha1 >> "$DOTEST"/current-commit
 
	# rewrite parents; if none were rewritten, we can fast-forward.
	new_parents=
	pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
	if test "$pend" = " "
	then
		pend=" root"
	fi
	while [ "$pend" != "" ]
	do
		p=$(expr "$pend" : ' \([^ ]*\)')
		pend="${pend# $p}"
 
		if test -f "$REWRITTEN"/$p
		then
			new_p=$(cat "$REWRITTEN"/$p)
 
			# If the todo reordered commits, and our parent is marked for
			# rewriting, but hasn't been gotten to yet, assume the user meant to
			# drop it on top of the current HEAD
			if test -z "$new_p"
			then
				new_p=$(git rev-parse HEAD)
			fi
 
			test $p != $new_p && fast_forward=f
			case "$new_parents" in
			*$new_p*)
				;; # do nothing; that parent is already there
			*)
				new_parents="$new_parents $new_p"
				;;
			esac
		else
			if test -f "$DROPPED"/$p
			then
				fast_forward=f
				replacement="$(cat "$DROPPED"/$p)"
				test -z "$replacement" && replacement=root
				pend=" $replacement$pend"
			else
				new_parents="$new_parents $p"
			fi
		fi
	done
	case $fast_forward in
	t)
		output warn "Fast-forward to $sha1"
		output git reset --hard $sha1 ||
			die "Cannot fast-forward to $sha1"
		;;
	f)
		first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
 
		if [ "$1" != "-n" ]
		then
			# detach HEAD to current parent
			output git checkout $first_parent 2> /dev/null ||
				die "Cannot move HEAD to $first_parent"
		fi
 
		case "$new_parents" in
		' '*' '*)
			test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 
			# redo merge
			author_script=$(get_author_ident_from_commit $sha1)
			eval "$author_script"
			msg="$(commit_message $sha1)"
			# No point in merging the first parent, that's HEAD
			new_parents=${new_parents# $first_parent}
			if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
				GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
				GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
				output git merge $STRATEGY -m "$msg" \
					$new_parents
			then
				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
				die_with_patch $sha1 "Error redoing merge $sha1"
			fi
			;;
		*)
			output git cherry-pick "$@" ||
				die_with_patch $sha1 "Could not pick $sha1"
			;;
		esac
		;;
	esac
}
 
nth_string () {
	case "$1" in
	*1[0-9]|*[04-9]) echo "$1"th;;
	*1) echo "$1"st;;
	*2) echo "$1"nd;;
	*3) echo "$1"rd;;
	esac
}
 
make_squash_message () {
	if test -f "$SQUASH_MSG"; then
		COUNT=$(($(sed -n \
			-e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
			-e "q" < "$SQUASH_MSG")+1))
		echo "# This is a combination of $COUNT commits."
		sed -e 1d -e '2,/^./{
			/^$/d
		}' <"$SQUASH_MSG"
	else
		COUNT=2
		echo "# This is a combination of 2 commits."
		echo "# The first commit's message is:"
		echo
		commit_message HEAD
	fi
	case $1 in
	squash)
		echo
		echo "# This is the $(nth_string $COUNT) commit message:"
		echo
		commit_message $2
		;;
	fixup)
		echo
		echo "# The $(nth_string $COUNT) commit message will be skipped:"
		echo
		commit_message $2 | sed -e 's/^/#	/'
		;;
	esac
}
 
peek_next_command () {
	sed -n -e "/^#/d" -e "/^$/d" -e "s/ .*//p" -e "q" < "$TODO"
}
 
do_next () {
	rm -f "$MSG" "$AUTHOR_SCRIPT" "$AMEND" || exit
	read command sha1 rest < "$TODO"
	case "$command" in
	'#'*|''|noop)
		mark_action_done
		;;
	pick|p)
		comment_for_reflog pick
 
		mark_action_done
		pick_one $sha1 ||
			die_with_patch $sha1 "Could not apply $sha1... $rest"
		;;
	reword|r)
		comment_for_reflog reword
 
		mark_action_done
		pick_one $sha1 ||
			die_with_patch $sha1 "Could not apply $sha1... $rest"
		git commit --amend
		;;
	edit|e)
		comment_for_reflog edit
 
		mark_action_done
		pick_one $sha1 ||
			die_with_patch $sha1 "Could not apply $sha1... $rest"
		make_patch $sha1
		git rev-parse --verify HEAD > "$AMEND"
		warn "Stopped at $sha1... $rest"
		warn "You can amend the commit now, with"
		warn
		warn "	git commit --amend"
		warn
		warn "Once you are satisfied with your changes, run"
		warn
		warn "	git rebase --continue"
		warn
		exit 0
		;;
	squash|s|fixup|f)
		case "$command" in
		squash|s)
			squash_style=squash
			;;
		fixup|f)
			squash_style=fixup
			;;
		esac
		comment_for_reflog $squash_style
 
		test -f "$DONE" && has_action "$DONE" ||
			die "Cannot '$squash_style' without a previous commit"
 
		mark_action_done
		make_squash_message $squash_style $sha1 > "$MSG"
		failed=f
		author_script=$(get_author_ident_from_commit HEAD)
		output git reset --soft HEAD^
		pick_one -n $sha1 || failed=t
		case "$(peek_next_command)" in
		squash|s|fixup|f)
			USE_OUTPUT=output
			MSG_OPT=-F
			EDIT_OR_FILE="$MSG"
			cp "$MSG" "$SQUASH_MSG"
			;;
		*)
			USE_OUTPUT=
			MSG_OPT=
			EDIT_OR_FILE=-e
			rm -f "$SQUASH_MSG" || exit
			cp "$MSG" "$GIT_DIR"/SQUASH_MSG
			rm -f "$GIT_DIR"/MERGE_MSG || exit
			;;
		esac
		echo "$author_script" > "$AUTHOR_SCRIPT"
		if test $failed = f
		then
			# This is like --amend, but with a different message
			eval "$author_script"
			GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
			GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
			GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
			$USE_OUTPUT git commit --no-verify \
				$MSG_OPT "$EDIT_OR_FILE" || failed=t
		fi
		if test $failed = t
		then
			cp "$MSG" "$GIT_DIR"/MERGE_MSG
			warn
			warn "Could not apply $sha1... $rest"
			die_with_patch $sha1 ""
		fi
		;;
	*)
		warn "Unknown command: $command $sha1 $rest"
		if git rev-parse --verify -q "$sha1" >/dev/null
		then
			die_with_patch $sha1 "Please fix this in the file $TODO."
		else
			die "Please fix this in the file $TODO."
		fi
		;;
	esac
	test -s "$TODO" && return
 
	comment_for_reflog finish &&
	HEADNAME=$(cat "$DOTEST"/head-name) &&
	OLDHEAD=$(cat "$DOTEST"/head) &&
	SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
	NEWHEAD=$(git rev-parse HEAD) &&
	case $HEADNAME in
	refs/*)
		message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO" &&
		git update-ref -m "$message" $HEADNAME $NEWHEAD $OLDHEAD &&
		git symbolic-ref HEAD $HEADNAME
		;;
	esac && {
		test ! -f "$DOTEST"/verbose ||
			git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
	} &&
	rm -rf "$DOTEST" &&
	git gc --auto &&
	warn "Successfully rebased and updated $HEADNAME."
 
	exit
}
 
do_rest () {
	while :
	do
		do_next
	done
}
 
# skip picking commits whose parents are unchanged
skip_unnecessary_picks () {
	fd=3
	while read command sha1 rest
	do
		# fd=3 means we skip the command
		case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
		3,pick,"$ONTO"*|3,p,"$ONTO"*)
			# pick a commit whose parent is current $ONTO -> skip
			ONTO=$sha1
			;;
		3,#*|3,,*)
			# copy comments
			;;
		*)
			fd=1
			;;
		esac
		echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
	done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
	mv -f "$TODO".new "$TODO" ||
	die "Could not skip unnecessary pick commands"
}
 
# check if no other options are set
is_standalone () {
	test $# -eq 2 -a "$2" = '--' &&
	test -z "$ONTO" &&
	test -z "$PRESERVE_MERGES" &&
	test -z "$STRATEGY" &&
	test -z "$VERBOSE"
}
 
get_saved_options () {
	test -d "$REWRITTEN" && PRESERVE_MERGES=t
	test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
	test -f "$DOTEST"/verbose && VERBOSE=t
	test -f "$DOTEST"/rebase-root && REBASE_ROOT=t
}
 
while test $# != 0
do
	case "$1" in
	--no-verify)
		OK_TO_SKIP_PRE_REBASE=yes
		;;
	--verify)
		;;
	--continue)
		is_standalone "$@" || usage
		get_saved_options
		comment_for_reflog continue
 
		test -d "$DOTEST" || die "No interactive rebase running"
 
		# Sanity check
		git rev-parse --verify HEAD >/dev/null ||
			die "Cannot read HEAD"
		git update-index --ignore-submodules --refresh &&
			git diff-files --quiet --ignore-submodules ||
			die "Working tree is dirty"
 
		# do we have anything to commit?
		if git diff-index --cached --quiet --ignore-submodules HEAD --
		then
			: Nothing to commit -- skip this
		else
			. "$AUTHOR_SCRIPT" ||
				die "Cannot find the author identity"
			amend=
			if test -f "$AMEND"
			then
				amend=$(git rev-parse --verify HEAD)
				test "$amend" = $(cat "$AMEND") ||
				die "\
You have uncommitted changes in your working tree. Please, commit them
first and then run 'git rebase --continue' again."
				git reset --soft HEAD^ ||
				die "Cannot rewind the HEAD"
			fi
			export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE &&
			git commit --no-verify -F "$MSG" -e || {
				test -n "$amend" && git reset --soft $amend
				die "Could not commit staged changes."
			}
		fi
 
		require_clean_work_tree
		do_rest
		;;
	--abort)
		is_standalone "$@" || usage
		get_saved_options
		comment_for_reflog abort
 
		git rerere clear
		test -d "$DOTEST" || die "No interactive rebase running"
 
		HEADNAME=$(cat "$DOTEST"/head-name)
		HEAD=$(cat "$DOTEST"/head)
		case $HEADNAME in
		refs/*)
			git symbolic-ref HEAD $HEADNAME
			;;
		esac &&
		output git reset --hard $HEAD &&
		rm -rf "$DOTEST"
		exit
		;;
	--skip)
		is_standalone "$@" || usage
		get_saved_options
		comment_for_reflog skip
 
		git rerere clear
		test -d "$DOTEST" || die "No interactive rebase running"
 
		output git reset --hard && do_rest
		;;
	-s)
		case "$#,$1" in
		*,*=*)
			STRATEGY="-s "$(expr "z$1" : 'z-[^=]*=\(.*\)') ;;
		1,*)
			usage ;;
		*)
			STRATEGY="-s $2"
			shift ;;
		esac
		;;
	-m)
		# we use merge anyway
		;;
	-v)
		VERBOSE=t
		;;
	-p)
		PRESERVE_MERGES=t
		;;
	-i)
		# yeah, we know
		;;
	--root)
		REBASE_ROOT=t
		;;
	--onto)
		shift
		ONTO=$(git rev-parse --verify "$1") ||
			die "Does not point to a valid commit: $1"
		;;
	--)
		shift
		test -z "$REBASE_ROOT" -a $# -ge 1 -a $# -le 2 ||
		test ! -z "$REBASE_ROOT" -a $# -le 1 || usage
		test -d "$DOTEST" &&
			die "Interactive rebase already started"
 
		git var GIT_COMMITTER_IDENT >/dev/null ||
			die "You need to set your committer info first"
 
		if test -z "$REBASE_ROOT"
		then
			UPSTREAM_ARG="$1"
			UPSTREAM=$(git rev-parse --verify "$1") || die "Invalid base"
			test -z "$ONTO" && ONTO=$UPSTREAM
			shift
		else
			UPSTREAM=
			UPSTREAM_ARG=--root
			test -z "$ONTO" &&
				die "You must specify --onto when using --root"
		fi
		run_pre_rebase_hook "$UPSTREAM_ARG" "$@"
 
		comment_for_reflog start
 
		require_clean_work_tree
 
		if test ! -z "$1"
		then
			output git show-ref --verify --quiet "refs/heads/$1" ||
				die "Invalid branchname: $1"
			output git checkout "$1" ||
				die "Could not checkout $1"
		fi
 
		HEAD=$(git rev-parse --verify HEAD) || die "No HEAD?"
		mkdir "$DOTEST" || die "Could not create temporary $DOTEST"
 
		: > "$DOTEST"/interactive || die "Could not mark as interactive"
		git symbolic-ref HEAD > "$DOTEST"/head-name 2> /dev/null ||
			echo "detached HEAD" > "$DOTEST"/head-name
 
		echo $HEAD > "$DOTEST"/head
		case "$REBASE_ROOT" in
		'')
			rm -f "$DOTEST"/rebase-root ;;
		*)
			: >"$DOTEST"/rebase-root ;;
		esac
		echo $ONTO > "$DOTEST"/onto
		test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
		test t = "$VERBOSE" && : > "$DOTEST"/verbose
		if test t = "$PRESERVE_MERGES"
		then
			if test -z "$REBASE_ROOT"
			then
				mkdir "$REWRITTEN" &&
				for c in $(git merge-base --all $HEAD $UPSTREAM)
				do
					echo $ONTO > "$REWRITTEN"/$c ||
						die "Could not init rewritten commits"
				done
			else
				mkdir "$REWRITTEN" &&
				echo $ONTO > "$REWRITTEN"/root ||
					die "Could not init rewritten commits"
			fi
			# No cherry-pick because our first pass is to determine
			# parents to rewrite and skipping dropped commits would
			# prematurely end our probe
			MERGES_OPTION=
			first_after_upstream="$(git rev-list --reverse --first-parent $UPSTREAM..$HEAD | head -n 1)"
		else
			MERGES_OPTION="--no-merges --cherry-pick"
		fi
 
		SHORTHEAD=$(git rev-parse --short $HEAD)
		SHORTONTO=$(git rev-parse --short $ONTO)
		if test -z "$REBASE_ROOT"
			# this is now equivalent to ! -z "$UPSTREAM"
		then
			SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
			REVISIONS=$UPSTREAM...$HEAD
			SHORTREVISIONS=$SHORTUPSTREAM..$SHORTHEAD
		else
			REVISIONS=$ONTO...$HEAD
			SHORTREVISIONS=$SHORTHEAD
		fi
		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
			--abbrev=7 --reverse --left-right --topo-order \
			$REVISIONS | \
			sed -n "s/^>//p" | while read shortsha1 rest
		do
			if test t != "$PRESERVE_MERGES"
			then
				echo "pick $shortsha1 $rest" >> "$TODO"
			else
				sha1=$(git rev-parse $shortsha1)
				if test -z "$REBASE_ROOT"
				then
					preserve=t
					for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
					do
						if test -f "$REWRITTEN"/$p -a \( $p != $ONTO -o $sha1 = $first_after_upstream \)
						then
							preserve=f
						fi
					done
				else
					preserve=f
				fi
				if test f = "$preserve"
				then
					touch "$REWRITTEN"/$sha1
					echo "pick $shortsha1 $rest" >> "$TODO"
				fi
			fi
		done
 
		# Watch for commits that been dropped by --cherry-pick
		if test t = "$PRESERVE_MERGES"
		then
			mkdir "$DROPPED"
			# Save all non-cherry-picked changes
			git rev-list $REVISIONS --left-right --cherry-pick | \
				sed -n "s/^>//p" > "$DOTEST"/not-cherry-picks
			# Now all commits and note which ones are missing in
			# not-cherry-picks and hence being dropped
			git rev-list $REVISIONS |
			while read rev
			do
				if test -f "$REWRITTEN"/$rev -a "$(sane_grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
				then
					# Use -f2 because if rev-list is telling us this commit is
					# not worthwhile, we don't want to track its multiple heads,
					# just the history of its first-parent for others that will
					# be rebasing on top of it
					git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
					short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
					sane_grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
					rm "$REWRITTEN"/$rev
				fi
			done
		fi
 
		test -s "$TODO" || echo noop >> "$TODO"
		cat >> "$TODO" << EOF
 
# Rebase $SHORTREVISIONS onto $SHORTONTO
#
# Commands:
#  p, pick = use commit
#  r, reword = use commit, but edit the commit message
#  e, edit = use commit, but stop for amending
#  s, squash = use commit, but meld into previous commit
#  f, fixup = like "squash", but discard this commit's log message
#
# If you remove a line here THAT COMMIT WILL BE LOST.
# However, if you remove everything, the rebase will be aborted.
#
EOF
 
		has_action "$TODO" ||
			die_abort "Nothing to do"
 
		cp "$TODO" "$TODO".backup
		git_editor "$TODO" ||
			die "Could not execute editor"
 
		has_action "$TODO" ||
			die_abort "Nothing to do"
 
		test -d "$REWRITTEN" || skip_unnecessary_picks
 
		git update-ref ORIG_HEAD $HEAD
		output git checkout $ONTO && do_rest
		;;
	esac
	shift
done