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