git-rebase--interactive.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2006 Johannes E. Schindelin
   4
   5 # SHORT DESCRIPTION
   6 #
   7 # This script makes it easy to fix up commits in the middle of a series,
   8 # and rearrange commits.
   9 #
  10 # The original idea comes from Eric W. Biederman, in
  11 # http://article.gmane.org/gmane.comp.version-control.git/22407
  12
  13 . git-sh-setup
  14
  15 # The file containing rebase commands, comments, and empty lines.
  16 # This file is created by "git rebase -i" then edited by the user.  As
  17 # the lines are processed, they are removed from the front of this
  18 # file and written to the tail of $done.
  19 todo="$state_dir"/git-rebase-todo
  20
  21 # The rebase command lines that have already been processed.  A line
  22 # is moved here when it is first handled, before any associated user
  23 # actions.
  24 done="$state_dir"/done
  25
  26 # The commit message that is planned to be used for any changes that
  27 # need to be committed following a user interaction.
  28 msg="$state_dir"/message
  29
  30 # The file into which is accumulated the suggested commit message for
  31 # squash/fixup commands.  When the first of a series of squash/fixups
  32 # is seen, the file is created and the commit message from the
  33 # previous commit and from the first squash/fixup commit are written
  34 # to it.  The commit message for each subsequent squash/fixup commit
  35 # is appended to the file as it is processed.
  36 #
  37 # The first line of the file is of the form
  38 #     # This is a combination of $count commits.
  39 # where $count is the number of commits whose messages have been
  40 # written to the file so far (including the initial "pick" commit).
  41 # Each time that a commit message is processed, this line is read and
  42 # updated.  It is deleted just before the combined commit is made.
  43 squash_msg="$state_dir"/message-squash
  44
  45 # If the current series of squash/fixups has not yet included a squash
  46 # command, then this file exists and holds the commit message of the
  47 # original "pick" commit.  (If the series ends without a "squash"
  48 # command, then this can be used as the commit message of the combined
  49 # commit without opening the editor.)
  50 fixup_msg="$state_dir"/message-fixup
  51
  52 # $rewritten is the name of a directory containing files for each
  53 # commit that is reachable by at least one merge base of $head and
  54 # $upstream. They are not necessarily rewritten, but their children
  55 # might be.  This ensures that commits on merged, but otherwise
  56 # unrelated side branches are left alone. (Think "X" in the man page's
  57 # example.)
  58 rewritten="$state_dir"/rewritten
  59
  60 dropped="$state_dir"/dropped
  61
  62 # A script to set the GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
  63 # GIT_AUTHOR_DATE that will be used for the commit that is currently
  64 # being rebased.
  65 author_script="$state_dir"/author-script
  66
  67 # When an "edit" rebase command is being processed, the SHA1 of the
  68 # commit to be edited is recorded in this file.  When "git rebase
  69 # --continue" is executed, if there are any staged changes then they
  70 # will be amended to the HEAD commit, but only provided the HEAD
  71 # commit is still the commit to be edited.  When any other rebase
  72 # command is processed, this file is deleted.
  73 amend="$state_dir"/amend
  74
  75 # For the post-rewrite hook, we make a list of rewritten commits and
  76 # their new sha1s.  The rewritten-pending list keeps the sha1s of
  77 # commits that have been processed, but not committed yet,
  78 # e.g. because they are waiting for a 'squash' command.
  79 rewritten_list="$state_dir"/rewritten-list
  80 rewritten_pending="$state_dir"/rewritten-pending
  81
  82 GIT_CHERRY_PICK_HELP="$resolvemsg"
  83 export GIT_CHERRY_PICK_HELP
  84
  85 warn () {
  86         printf '%s\n' "$*" >&2
  87 }
  88
  89 # Output the commit message for the specified commit.
  90 commit_message () {
  91         git cat-file commit "$1" | sed "1,/^$/d"
  92 }
  93
  94 orig_reflog_action="$GIT_REFLOG_ACTION"
  95
  96 comment_for_reflog () {
  97         case "$orig_reflog_action" in
  98         ''|rebase*)
  99                 GIT_REFLOG_ACTION="rebase -i ($1)"
 100                 export GIT_REFLOG_ACTION
 101                 ;;
 102         esac
 103 }
 104
 105 last_count=
 106 mark_action_done () {
 107         sed -e 1q < "$todo" >> "$done"
 108         sed -e 1d < "$todo" >> "$todo".new
 109         mv -f "$todo".new "$todo"
 110         new_count=$(sane_grep -c '^[^#]' < "$done")
 111         total=$(($new_count+$(sane_grep -c '^[^#]' < "$todo")))
 112         if test "$last_count" != "$new_count"
 113         then
 114                 last_count=$new_count
 115                 printf "Rebasing (%d/%d)\r" $new_count $total
 116                 test -z "$verbose" || echo
 117         fi
 118 }
 119
 120 make_patch () {
 121         sha1_and_parents="$(git rev-list --parents -1 "$1")"
 122         case "$sha1_and_parents" in
 123         ?*' '?*' '?*)
 124                 git diff --cc $sha1_and_parents
 125                 ;;
 126         ?*' '?*)
 127                 git diff-tree -p "$1^!"
 128                 ;;
 129         *)
 130                 echo "Root commit"
 131                 ;;
 132         esac > "$state_dir"/patch
 133         test -f "$msg" ||
 134                 commit_message "$1" > "$msg"
 135         test -f "$author_script" ||
 136                 get_author_ident_from_commit "$1" > "$author_script"
 137 }
 138
 139 die_with_patch () {
 140         echo "$1" > "$state_dir"/stopped-sha
 141         make_patch "$1"
 142         git rerere
 143         die "$2"
 144 }
 145
 146 die_abort () {
 147         rm -rf "$state_dir"
 148         die "$1"
 149 }
 150
 151 has_action () {
 152         sane_grep '^[^#]' "$1" >/dev/null
 153 }
 154
 155 # Run command with GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL, and
 156 # GIT_AUTHOR_DATE exported from the current environment.
 157 do_with_author () {
 158         (
 159                 export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
 160                 "$@"
 161         )
 162 }
 163
 164 pick_one () {
 165         ff=--ff
 166         case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
 167         case "$force_rebase" in '') ;; ?*) ff= ;; esac
 168         output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
 169         test -d "$rewritten" &&
 170                 pick_one_preserving_merges "$@" && return
 171         output git cherry-pick $ff "$@"
 172 }
 173
 174 pick_one_preserving_merges () {
 175         fast_forward=t
 176         case "$1" in
 177         -n)
 178                 fast_forward=f
 179                 sha1=$2
 180                 ;;
 181         *)
 182                 sha1=$1
 183                 ;;
 184         esac
 185         sha1=$(git rev-parse $sha1)
 186
 187         if test -f "$state_dir"/current-commit
 188         then
 189                 if test "$fast_forward" = t
 190                 then
 191                         while read current_commit
 192                         do
 193                                 git rev-parse HEAD > "$rewritten"/$current_commit
 194                         done <"$state_dir"/current-commit
 195                         rm "$state_dir"/current-commit ||
 196                         die "Cannot write current commit's replacement sha1"
 197                 fi
 198         fi
 199
 200         echo $sha1 >> "$state_dir"/current-commit
 201
 202         # rewrite parents; if none were rewritten, we can fast-forward.
 203         new_parents=
 204         pend=" $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)"
 205         if test "$pend" = " "
 206         then
 207                 pend=" root"
 208         fi
 209         while [ "$pend" != "" ]
 210         do
 211                 p=$(expr "$pend" : ' \([^ ]*\)')
 212                 pend="${pend# $p}"
 213
 214                 if test -f "$rewritten"/$p
 215                 then
 216                         new_p=$(cat "$rewritten"/$p)
 217
 218                         # If the todo reordered commits, and our parent is marked for
 219                         # rewriting, but hasn't been gotten to yet, assume the user meant to
 220                         # drop it on top of the current HEAD
 221                         if test -z "$new_p"
 222                         then
 223                                 new_p=$(git rev-parse HEAD)
 224                         fi
 225
 226                         test $p != $new_p && fast_forward=f
 227                         case "$new_parents" in
 228                         *$new_p*)
 229                                 ;; # do nothing; that parent is already there
 230                         *)
 231                                 new_parents="$new_parents $new_p"
 232                                 ;;
 233                         esac
 234                 else
 235                         if test -f "$dropped"/$p
 236                         then
 237                                 fast_forward=f
 238                                 replacement="$(cat "$dropped"/$p)"
 239                                 test -z "$replacement" && replacement=root
 240                                 pend=" $replacement$pend"
 241                         else
 242                                 new_parents="$new_parents $p"
 243                         fi
 244                 fi
 245         done
 246         case $fast_forward in
 247         t)
 248                 output warn "Fast-forward to $sha1"
 249                 output git reset --hard $sha1 ||
 250                         die "Cannot fast-forward to $sha1"
 251                 ;;
 252         f)
 253                 first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
 254
 255                 if [ "$1" != "-n" ]
 256                 then
 257                         # detach HEAD to current parent
 258                         output git checkout $first_parent 2> /dev/null ||
 259                                 die "Cannot move HEAD to $first_parent"
 260                 fi
 261
 262                 case "$new_parents" in
 263                 ' '*' '*)
 264                         test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
 265
 266                         # redo merge
 267                         author_script_content=$(get_author_ident_from_commit $sha1)
 268                         eval "$author_script_content"
 269                         msg_content="$(commit_message $sha1)"
 270                         # No point in merging the first parent, that's HEAD
 271                         new_parents=${new_parents# $first_parent}
 272                         if ! do_with_author output \
 273                                 git merge --no-ff ${strategy:+-s $strategy} -m \
 274                                         "$msg_content" $new_parents
 275                         then
 276                                 printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
 277                                 die_with_patch $sha1 "Error redoing merge $sha1"
 278                         fi
 279                         echo "$sha1 $(git rev-parse HEAD^0)" >> "$rewritten_list"
 280                         ;;
 281                 *)
 282                         output git cherry-pick "$@" ||
 283                                 die_with_patch $sha1 "Could not pick $sha1"
 284                         ;;
 285                 esac
 286                 ;;
 287         esac
 288 }
 289
 290 nth_string () {
 291         case "$1" in
 292         *1[0-9]|*[04-9]) echo "$1"th;;
 293         *1) echo "$1"st;;
 294         *2) echo "$1"nd;;
 295         *3) echo "$1"rd;;
 296         esac
 297 }
 298
 299 update_squash_messages () {
 300         if test -f "$squash_msg"; then
 301                 mv "$squash_msg" "$squash_msg".bak || exit
 302                 count=$(($(sed -n \
 303                         -e "1s/^# This is a combination of \(.*\) commits\./\1/p" \
 304                         -e "q" < "$squash_msg".bak)+1))
 305                 {
 306                         echo "# This is a combination of $count commits."
 307                         sed -e 1d -e '2,/^./{
 308                                 /^$/d
 309                         }' <"$squash_msg".bak
 310                 } >"$squash_msg"
 311         else
 312                 commit_message HEAD > "$fixup_msg" || die "Cannot write $fixup_msg"
 313                 count=2
 314                 {
 315                         echo "# This is a combination of 2 commits."
 316                         echo "# The first commit's message is:"
 317                         echo
 318                         cat "$fixup_msg"
 319                 } >"$squash_msg"
 320         fi
 321         case $1 in
 322         squash)
 323                 rm -f "$fixup_msg"
 324                 echo
 325                 echo "# This is the $(nth_string $count) commit message:"
 326                 echo
 327                 commit_message $2
 328                 ;;
 329         fixup)
 330                 echo
 331                 echo "# The $(nth_string $count) commit message will be skipped:"
 332                 echo
 333                 commit_message $2 | sed -e 's/^/#       /'
 334                 ;;
 335         esac >>"$squash_msg"
 336 }
 337
 338 peek_next_command () {
 339         sed -n -e "/^#/d" -e '/^$/d' -e "s/ .*//p" -e "q" < "$todo"
 340 }
 341
 342 # A squash/fixup has failed.  Prepare the long version of the squash
 343 # commit message, then die_with_patch.  This code path requires the
 344 # user to edit the combined commit message for all commits that have
 345 # been squashed/fixedup so far.  So also erase the old squash
 346 # messages, effectively causing the combined commit to be used as the
 347 # new basis for any further squash/fixups.  Args: sha1 rest
 348 die_failed_squash() {
 349         mv "$squash_msg" "$msg" || exit
 350         rm -f "$fixup_msg"
 351         cp "$msg" "$GIT_DIR"/MERGE_MSG || exit
 352         warn
 353         warn "Could not apply $1... $2"
 354         die_with_patch $1 ""
 355 }
 356
 357 flush_rewritten_pending() {
 358         test -s "$rewritten_pending" || return
 359         newsha1="$(git rev-parse HEAD^0)"
 360         sed "s/$/ $newsha1/" < "$rewritten_pending" >> "$rewritten_list"
 361         rm -f "$rewritten_pending"
 362 }
 363
 364 record_in_rewritten() {
 365         oldsha1="$(git rev-parse $1)"
 366         echo "$oldsha1" >> "$rewritten_pending"
 367
 368         case "$(peek_next_command)" in
 369         squash|s|fixup|f)
 370                 ;;
 371         *)
 372                 flush_rewritten_pending
 373                 ;;
 374         esac
 375 }
 376
 377 do_next () {
 378         rm -f "$msg" "$author_script" "$amend" || exit
 379         read -r command sha1 rest < "$todo"
 380         case "$command" in
 381         '#'*|''|noop)
 382                 mark_action_done
 383                 ;;
 384         pick|p)
 385                 comment_for_reflog pick
 386
 387                 mark_action_done
 388                 pick_one $sha1 ||
 389                         die_with_patch $sha1 "Could not apply $sha1... $rest"
 390                 record_in_rewritten $sha1
 391                 ;;
 392         reword|r)
 393                 comment_for_reflog reword
 394
 395                 mark_action_done
 396                 pick_one $sha1 ||
 397                         die_with_patch $sha1 "Could not apply $sha1... $rest"
 398                 git commit --amend --no-post-rewrite
 399                 record_in_rewritten $sha1
 400                 ;;
 401         edit|e)
 402                 comment_for_reflog edit
 403
 404                 mark_action_done
 405                 pick_one $sha1 ||
 406                         die_with_patch $sha1 "Could not apply $sha1... $rest"
 407                 echo "$sha1" > "$state_dir"/stopped-sha
 408                 make_patch $sha1
 409                 git rev-parse --verify HEAD > "$amend"
 410                 warn "Stopped at $sha1... $rest"
 411                 warn "You can amend the commit now, with"
 412                 warn
 413                 warn "  git commit --amend"
 414                 warn
 415                 warn "Once you are satisfied with your changes, run"
 416                 warn
 417                 warn "  git rebase --continue"
 418                 warn
 419                 exit 0
 420                 ;;
 421         squash|s|fixup|f)
 422                 case "$command" in
 423                 squash|s)
 424                         squash_style=squash
 425                         ;;
 426                 fixup|f)
 427                         squash_style=fixup
 428                         ;;
 429                 esac
 430                 comment_for_reflog $squash_style
 431
 432                 test -f "$done" && has_action "$done" ||
 433                         die "Cannot '$squash_style' without a previous commit"
 434
 435                 mark_action_done
 436                 update_squash_messages $squash_style $sha1
 437                 author_script_content=$(get_author_ident_from_commit HEAD)
 438                 echo "$author_script_content" > "$author_script"
 439                 eval "$author_script_content"
 440                 output git reset --soft HEAD^
 441                 pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
 442                 case "$(peek_next_command)" in
 443                 squash|s|fixup|f)
 444                         # This is an intermediate commit; its message will only be
 445                         # used in case of trouble.  So use the long version:
 446                         do_with_author output git commit --no-verify -F "$squash_msg" ||
 447                                 die_failed_squash $sha1 "$rest"
 448                         ;;
 449                 *)
 450                         # This is the final command of this squash/fixup group
 451                         if test -f "$fixup_msg"
 452                         then
 453                                 do_with_author git commit --no-verify -F "$fixup_msg" ||
 454                                         die_failed_squash $sha1 "$rest"
 455                         else
 456                                 cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
 457                                 rm -f "$GIT_DIR"/MERGE_MSG
 458                                 do_with_author git commit --no-verify -e ||
 459                                         die_failed_squash $sha1 "$rest"
 460                         fi
 461                         rm -f "$squash_msg" "$fixup_msg"
 462                         ;;
 463                 esac
 464                 record_in_rewritten $sha1
 465                 ;;
 466         x|"exec")
 467                 read -r command rest < "$todo"
 468                 mark_action_done
 469                 printf 'Executing: %s\n' "$rest"
 470                 # "exec" command doesn't take a sha1 in the todo-list.
 471                 # => can't just use $sha1 here.
 472                 git rev-parse --verify HEAD > "$state_dir"/stopped-sha
 473                 ${SHELL:-@SHELL_PATH@} -c "$rest" # Actual execution
 474                 status=$?
 475                 if test "$status" -ne 0
 476                 then
 477                         warn "Execution failed: $rest"
 478                         warn "You can fix the problem, and then run"
 479                         warn
 480                         warn "  git rebase --continue"
 481                         warn
 482                         exit "$status"
 483                 fi
 484                 # Run in subshell because require_clean_work_tree can die.
 485                 if ! (require_clean_work_tree "rebase")
 486                 then
 487                         warn "Commit or stash your changes, and then run"
 488                         warn
 489                         warn "  git rebase --continue"
 490                         warn
 491                         exit 1
 492                 fi
 493                 ;;
 494         *)
 495                 warn "Unknown command: $command $sha1 $rest"
 496                 if git rev-parse --verify -q "$sha1" >/dev/null
 497                 then
 498                         die_with_patch $sha1 "Please fix this in the file $todo."
 499                 else
 500                         die "Please fix this in the file $todo."
 501                 fi
 502                 ;;
 503         esac
 504         test -s "$todo" && return
 505
 506         comment_for_reflog finish &&
 507         shortonto=$(git rev-parse --short $onto) &&
 508         newhead=$(git rev-parse HEAD) &&
 509         case $head_name in
 510         refs/*)
 511                 message="$GIT_REFLOG_ACTION: $head_name onto $shortonto" &&
 512                 git update-ref -m "$message" $head_name $newhead $orig_head &&
 513                 git symbolic-ref HEAD $head_name
 514                 ;;
 515         esac && {
 516                 test ! -f "$state_dir"/verbose ||
 517                         git diff-tree --stat $orig_head..HEAD
 518         } &&
 519         {
 520                 test -s "$rewritten_list" &&
 521                 git notes copy --for-rewrite=rebase < "$rewritten_list" ||
 522                 true # we don't care if this copying failed
 523         } &&
 524         if test -x "$GIT_DIR"/hooks/post-rewrite &&
 525                 test -s "$rewritten_list"; then
 526                 "$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
 527                 true # we don't care if this hook failed
 528         fi &&
 529         rm -rf "$state_dir" &&
 530         git gc --auto &&
 531         warn "Successfully rebased and updated $head_name."
 532
 533         exit
 534 }
 535
 536 do_rest () {
 537         while :
 538         do
 539                 do_next
 540         done
 541 }
 542
 543 # skip picking commits whose parents are unchanged
 544 skip_unnecessary_picks () {
 545         fd=3
 546         while read -r command rest
 547         do
 548                 # fd=3 means we skip the command
 549                 case "$fd,$command" in
 550                 3,pick|3,p)
 551                         # pick a commit whose parent is current $onto -> skip
 552                         sha1=${rest%% *}
 553                         case "$(git rev-parse --verify --quiet "$sha1"^)" in
 554                         "$onto"*)
 555                                 onto=$sha1
 556                                 ;;
 557                         *)
 558                                 fd=1
 559                                 ;;
 560                         esac
 561                         ;;
 562                 3,#*|3,)
 563                         # copy comments
 564                         ;;
 565                 *)
 566                         fd=1
 567                         ;;
 568                 esac
 569                 printf '%s\n' "$command${rest:+ }$rest" >&$fd
 570         done <"$todo" >"$todo.new" 3>>"$done" &&
 571         mv -f "$todo".new "$todo" &&
 572         case "$(peek_next_command)" in
 573         squash|s|fixup|f)
 574                 record_in_rewritten "$onto"
 575                 ;;
 576         esac ||
 577         die "Could not skip unnecessary pick commands"
 578 }
 579
 580 # Rearrange the todo list that has both "pick sha1 msg" and
 581 # "pick sha1 fixup!/squash! msg" appears in it so that the latter
 582 # comes immediately after the former, and change "pick" to
 583 # "fixup"/"squash".
 584 rearrange_squash () {
 585         # extract fixup!/squash! lines and resolve any referenced sha1's
 586         while read -r pick sha1 message
 587         do
 588                 case "$message" in
 589                 "squash! "*|"fixup! "*)
 590                         action="${message%%!*}"
 591                         rest="${message#*! }"
 592                         echo "$sha1 $action $rest"
 593                         # if it's a single word, try to resolve to a full sha1 and
 594                         # emit a second copy. This allows us to match on both message
 595                         # and on sha1 prefix
 596                         if test "${rest#* }" = "$rest"; then
 597                                 fullsha="$(git rev-parse -q --verify "$rest" 2>/dev/null)"
 598                                 if test -n "$fullsha"; then
 599                                         # prefix the action to uniquely identify this line as
 600                                         # intended for full sha1 match
 601                                         echo "$sha1 +$action $fullsha"
 602                                 fi
 603                         fi
 604                 esac
 605         done >"$1.sq" <"$1"
 606         test -s "$1.sq" || return
 607
 608         used=
 609         while read -r pick sha1 message
 610         do
 611                 case " $used" in
 612                 *" $sha1 "*) continue ;;
 613                 esac
 614                 printf '%s\n' "$pick $sha1 $message"
 615                 used="$used$sha1 "
 616                 while read -r squash action msg_content
 617                 do
 618                         case " $used" in
 619                         *" $squash "*) continue ;;
 620                         esac
 621                         emit=0
 622                         case "$action" in
 623                         +*)
 624                                 action="${action#+}"
 625                                 # full sha1 prefix test
 626                                 case "$msg_content" in "$sha1"*) emit=1;; esac ;;
 627                         *)
 628                                 # message prefix test
 629                                 case "$message" in "$msg_content"*) emit=1;; esac ;;
 630                         esac
 631                         if test $emit = 1; then
 632                                 printf '%s\n' "$action $squash $action! $msg_content"
 633                                 used="$used$squash "
 634                         fi
 635                 done <"$1.sq"
 636         done >"$1.rearranged" <"$1"
 637         cat "$1.rearranged" >"$1"
 638         rm -f "$1.sq" "$1.rearranged"
 639 }
 640
 641 case "$action" in
 642 continue)
 643         # do we have anything to commit?
 644         if git diff-index --cached --quiet --ignore-submodules HEAD --
 645         then
 646                 : Nothing to commit -- skip this
 647         else
 648                 . "$author_script" ||
 649                         die "Cannot find the author identity"
 650                 current_head=
 651                 if test -f "$amend"
 652                 then
 653                         current_head=$(git rev-parse --verify HEAD)
 654                         test "$current_head" = $(cat "$amend") ||
 655                         die "\
 656 You have uncommitted changes in your working tree. Please, commit them
 657 first and then run 'git rebase --continue' again."
 658                         git reset --soft HEAD^ ||
 659                         die "Cannot rewind the HEAD"
 660                 fi
 661                 do_with_author git commit --no-verify -F "$msg" -e || {
 662                         test -n "$current_head" && git reset --soft $current_head
 663                         die "Could not commit staged changes."
 664                 }
 665         fi
 666
 667         record_in_rewritten "$(cat "$state_dir"/stopped-sha)"
 668
 669         require_clean_work_tree "rebase"
 670         do_rest
 671         ;;
 672 skip)
 673         git rerere clear
 674
 675         do_rest
 676         ;;
 677 esac
 678
 679 git var GIT_COMMITTER_IDENT >/dev/null ||
 680         die "You need to set your committer info first"
 681
 682 comment_for_reflog start
 683
 684 if test ! -z "$switch_to"
 685 then
 686         output git checkout "$switch_to" -- ||
 687                 die "Could not checkout $switch_to"
 688 fi
 689
 690 orig_head=$(git rev-parse --verify HEAD) || die "No HEAD?"
 691 mkdir "$state_dir" || die "Could not create temporary $state_dir"
 692
 693 : > "$state_dir"/interactive || die "Could not mark as interactive"
 694 write_basic_state
 695 if test t = "$preserve_merges"
 696 then
 697         if test -z "$rebase_root"
 698         then
 699                 mkdir "$rewritten" &&
 700                 for c in $(git merge-base --all $orig_head $upstream)
 701                 do
 702                         echo $onto > "$rewritten"/$c ||
 703                                 die "Could not init rewritten commits"
 704                 done
 705         else
 706                 mkdir "$rewritten" &&
 707                 echo $onto > "$rewritten"/root ||
 708                         die "Could not init rewritten commits"
 709         fi
 710         # No cherry-pick because our first pass is to determine
 711         # parents to rewrite and skipping dropped commits would
 712         # prematurely end our probe
 713         merges_option=
 714         first_after_upstream="$(git rev-list --reverse --first-parent $upstream..$orig_head | head -n 1)"
 715 else
 716         merges_option="--no-merges --cherry-pick"
 717 fi
 718
 719 shorthead=$(git rev-parse --short $orig_head)
 720 shortonto=$(git rev-parse --short $onto)
 721 if test -z "$rebase_root"
 722         # this is now equivalent to ! -z "$upstream"
 723 then
 724         shortupstream=$(git rev-parse --short $upstream)
 725         revisions=$upstream...$orig_head
 726         shortrevisions=$shortupstream..$shorthead
 727 else
 728         revisions=$onto...$orig_head
 729         shortrevisions=$shorthead
 730 fi
 731 git rev-list $merges_option --pretty=oneline --abbrev-commit \
 732         --abbrev=7 --reverse --left-right --topo-order \
 733         $revisions | \
 734         sed -n "s/^>//p" |
 735 while read -r shortsha1 rest
 736 do
 737         if test t != "$preserve_merges"
 738         then
 739                 printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
 740         else
 741                 sha1=$(git rev-parse $shortsha1)
 742                 if test -z "$rebase_root"
 743                 then
 744                         preserve=t
 745                         for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-)
 746                         do
 747                                 if test -f "$rewritten"/$p -a \( $p != $onto -o $sha1 = $first_after_upstream \)
 748                                 then
 749                                         preserve=f
 750                                 fi
 751                         done
 752                 else
 753                         preserve=f
 754                 fi
 755                 if test f = "$preserve"
 756                 then
 757                         touch "$rewritten"/$sha1
 758                         printf '%s\n' "pick $shortsha1 $rest" >> "$todo"
 759                 fi
 760         fi
 761 done
 762
 763 # Watch for commits that been dropped by --cherry-pick
 764 if test t = "$preserve_merges"
 765 then
 766         mkdir "$dropped"
 767         # Save all non-cherry-picked changes
 768         git rev-list $revisions --left-right --cherry-pick | \
 769                 sed -n "s/^>//p" > "$state_dir"/not-cherry-picks
 770         # Now all commits and note which ones are missing in
 771         # not-cherry-picks and hence being dropped
 772         git rev-list $revisions |
 773         while read rev
 774         do
 775                 if test -f "$rewritten"/$rev -a "$(sane_grep "$rev" "$state_dir"/not-cherry-picks)" = ""
 776                 then
 777                         # Use -f2 because if rev-list is telling us this commit is
 778                         # not worthwhile, we don't want to track its multiple heads,
 779                         # just the history of its first-parent for others that will
 780                         # be rebasing on top of it
 781                         git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$dropped"/$rev
 782                         short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
 783                         sane_grep -v "^[a-z][a-z]* $short" <"$todo" > "${todo}2" ; mv "${todo}2" "$todo"
 784                         rm "$rewritten"/$rev
 785                 fi
 786         done
 787 fi
 788
 789 test -s "$todo" || echo noop >> "$todo"
 790 test -n "$autosquash" && rearrange_squash "$todo"
 791 cat >> "$todo" << EOF
 792
 793 # Rebase $shortrevisions onto $shortonto
 794 #
 795 # Commands:
 796 #  p, pick = use commit
 797 #  r, reword = use commit, but edit the commit message
 798 #  e, edit = use commit, but stop for amending
 799 #  s, squash = use commit, but meld into previous commit
 800 #  f, fixup = like "squash", but discard this commit's log message
 801 #  x, exec = run command (the rest of the line) using shell
 802 #
 803 # If you remove a line here THAT COMMIT WILL BE LOST.
 804 # However, if you remove everything, the rebase will be aborted.
 805 #
 806 EOF
 807
 808 has_action "$todo" ||
 809         die_abort "Nothing to do"
 810
 811 cp "$todo" "$todo".backup
 812 git_editor "$todo" ||
 813         die_abort "Could not execute editor"
 814
 815 has_action "$todo" ||
 816         die_abort "Nothing to do"
 817
 818 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
 819
 820 output git checkout $onto || die_abort "could not detach HEAD"
 821 git update-ref ORIG_HEAD $orig_head
 822 do_rest