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