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