git.oblomov.eu Git - git/blob - contrib/subtree/git-subtree.sh

   1 #!/bin/sh
   2 #
   3 # git-subtree.sh: split/join git repositories in subdirectories of this one
   4 #
   5 # Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
   6 #
   7
   8 if test -z "$GIT_EXEC_PATH" || test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" || ! test -f "$GIT_EXEC_PATH/git-sh-setup"
   9 then
  10         echo >&2 'It looks like either your git installation or your'
  11         echo >&2 'git-subtree installation is broken.'
  12         echo >&2
  13         echo >&2 "Tips:"
  14         echo >&2 " - If \`git --exec-path\` does not print the correct path to"
  15         echo >&2 "   your git install directory, then set the GIT_EXEC_PATH"
  16         echo >&2 "   environment variable to the correct directory."
  17         echo >&2 " - Make sure that your \`${0##*/}\` file is either in your"
  18         echo >&2 "   PATH or in your git exec path (\`$(git --exec-path)\`)."
  19         echo >&2 " - You should run git-subtree as \`git ${0##*/git-}\`,"
  20         echo >&2 "   not as \`${0##*/}\`." >&2
  21         exit 126
  22 fi
  23
  24 OPTS_SPEC="\
  25 git subtree add   --prefix=<prefix> <commit>
  26 git subtree add   --prefix=<prefix> <repository> <ref>
  27 git subtree merge --prefix=<prefix> <commit>
  28 git subtree split --prefix=<prefix> [<commit>]
  29 git subtree pull  --prefix=<prefix> <repository> <ref>
  30 git subtree push  --prefix=<prefix> <repository> <refspec>
  31 --
  32 h,help        show the help
  33 q             quiet
  34 d             show debug messages
  35 P,prefix=     the name of the subdir to split out
  36  options for 'split' (also: 'push')
  37 annotate=     add a prefix to commit message of new commits
  38 b,branch=     create a new branch from the split subtree
  39 ignore-joins  ignore prior --rejoin commits
  40 onto=         try connecting new tree to an existing one
  41 rejoin        merge the new branch back into HEAD
  42  options for 'add' and 'merge' (also: 'pull', 'split --rejoin', and 'push --rejoin')
  43 squash        merge subtree changes as a single commit
  44 m,message=    use the given message as the commit message for the merge commit
  45 "
  46
  47 indent=0
  48
  49 # Usage: debug [MSG...]
  50 debug () {
  51         if test -n "$arg_debug"
  52         then
  53                 printf "%$(($indent * 2))s%s\n" '' "$*" >&2
  54         fi
  55 }
  56
  57 # Usage: progress [MSG...]
  58 progress () {
  59         if test -z "$GIT_QUIET"
  60         then
  61                 if test -z "$arg_debug"
  62                 then
  63                         # Debug mode is off.
  64                         #
  65                         # Print one progress line that we keep updating (use
  66                         # "\r" to return to the beginning of the line, rather
  67                         # than "\n" to start a new line).  This only really
  68                         # works when stderr is a terminal.
  69                         printf "%s\r" "$*" >&2
  70                 else
  71                         # Debug mode is on.  The `debug` function is regularly
  72                         # printing to stderr.
  73                         #
  74                         # Don't do the one-line-with-"\r" thing, because on a
  75                         # terminal the debug output would overwrite and hide the
  76                         # progress output.  Add a "progress:" prefix to make the
  77                         # progress output and the debug output easy to
  78                         # distinguish.  This ensures maximum readability whether
  79                         # stderr is a terminal or a file.
  80                         printf "progress: %s\n" "$*" >&2
  81                 fi
  82         fi
  83 }
  84
  85 # Usage: assert CMD...
  86 assert () {
  87         if ! "$@"
  88         then
  89                 die "assertion failed: $*"
  90         fi
  91 }
  92
  93 main () {
  94         if test $# -eq 0
  95         then
  96                 set -- -h
  97         fi
  98         set_args="$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
  99         eval "$set_args"
 100         . git-sh-setup
 101         require_work_tree
 102
 103         # First figure out the command and whether we use --rejoin, so
 104         # that we can provide more helpful validation when we do the
 105         # "real" flag parsing.
 106         arg_split_rejoin=
 107         allow_split=
 108         allow_addmerge=
 109         while test $# -gt 0
 110         do
 111                 opt="$1"
 112                 shift
 113                 case "$opt" in
 114                         --annotate|-b|-P|-m|--onto)
 115                                 shift
 116                                 ;;
 117                         --rejoin)
 118                                 arg_split_rejoin=1
 119                                 ;;
 120                         --no-rejoin)
 121                                 arg_split_rejoin=
 122                                 ;;
 123                         --)
 124                                 break
 125                                 ;;
 126                 esac
 127         done
 128         arg_command=$1
 129         case "$arg_command" in
 130         add|merge|pull)
 131                 allow_addmerge=1
 132                 ;;
 133         split|push)
 134                 allow_split=1
 135                 allow_addmerge=$arg_split_rejoin
 136                 ;;
 137         *)
 138                 die "Unknown command '$arg_command'"
 139                 ;;
 140         esac
 141         # Reset the arguments array for "real" flag parsing.
 142         eval "$set_args"
 143
 144         # Begin "real" flag parsing.
 145         arg_debug=
 146         arg_prefix=
 147         arg_split_branch=
 148         arg_split_onto=
 149         arg_split_ignore_joins=
 150         arg_split_annotate=
 151         arg_addmerge_squash=
 152         arg_addmerge_message=
 153         while test $# -gt 0
 154         do
 155                 opt="$1"
 156                 shift
 157
 158                 case "$opt" in
 159                 -q)
 160                         GIT_QUIET=1
 161                         ;;
 162                 -d)
 163                         arg_debug=1
 164                         ;;
 165                 --annotate)
 166                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 167                         arg_split_annotate="$1"
 168                         shift
 169                         ;;
 170                 --no-annotate)
 171                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 172                         arg_split_annotate=
 173                         ;;
 174                 -b)
 175                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 176                         arg_split_branch="$1"
 177                         shift
 178                         ;;
 179                 -P)
 180                         arg_prefix="${1%/}"
 181                         shift
 182                         ;;
 183                 -m)
 184                         test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 185                         arg_addmerge_message="$1"
 186                         shift
 187                         ;;
 188                 --no-prefix)
 189                         arg_prefix=
 190                         ;;
 191                 --onto)
 192                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 193                         arg_split_onto="$1"
 194                         shift
 195                         ;;
 196                 --no-onto)
 197                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 198                         arg_split_onto=
 199                         ;;
 200                 --rejoin)
 201                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 202                         ;;
 203                 --no-rejoin)
 204                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 205                         ;;
 206                 --ignore-joins)
 207                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 208                         arg_split_ignore_joins=1
 209                         ;;
 210                 --no-ignore-joins)
 211                         test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 212                         arg_split_ignore_joins=
 213                         ;;
 214                 --squash)
 215                         test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 216                         arg_addmerge_squash=1
 217                         ;;
 218                 --no-squash)
 219                         test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 220                         arg_addmerge_squash=
 221                         ;;
 222                 --)
 223                         break
 224                         ;;
 225                 *)
 226                         die "Unexpected option: $opt"
 227                         ;;
 228                 esac
 229         done
 230         shift
 231
 232         if test -z "$arg_prefix"
 233         then
 234                 die "You must provide the --prefix option."
 235         fi
 236
 237         case "$arg_command" in
 238         add)
 239                 test -e "$arg_prefix" &&
 240                         die "prefix '$arg_prefix' already exists."
 241                 ;;
 242         *)
 243                 test -e "$arg_prefix" ||
 244                         die "'$arg_prefix' does not exist; use 'git subtree add'"
 245                 ;;
 246         esac
 247
 248         dir="$(dirname "$arg_prefix/.")"
 249
 250         debug "command: {$arg_command}"
 251         debug "quiet: {$GIT_QUIET}"
 252         debug "dir: {$dir}"
 253         debug "opts: {$*}"
 254         debug
 255
 256         "cmd_$arg_command" "$@"
 257 }
 258
 259 # Usage: cache_setup
 260 cache_setup () {
 261         assert test $# = 0
 262         cachedir="$GIT_DIR/subtree-cache/$$"
 263         rm -rf "$cachedir" ||
 264                 die "Can't delete old cachedir: $cachedir"
 265         mkdir -p "$cachedir" ||
 266                 die "Can't create new cachedir: $cachedir"
 267         mkdir -p "$cachedir/notree" ||
 268                 die "Can't create new cachedir: $cachedir/notree"
 269         debug "Using cachedir: $cachedir" >&2
 270 }
 271
 272 # Usage: cache_get [REVS...]
 273 cache_get () {
 274         for oldrev in "$@"
 275         do
 276                 if test -r "$cachedir/$oldrev"
 277                 then
 278                         read newrev <"$cachedir/$oldrev"
 279                         echo $newrev
 280                 fi
 281         done
 282 }
 283
 284 # Usage: cache_miss [REVS...]
 285 cache_miss () {
 286         for oldrev in "$@"
 287         do
 288                 if ! test -r "$cachedir/$oldrev"
 289                 then
 290                         echo $oldrev
 291                 fi
 292         done
 293 }
 294
 295 # Usage: check_parents PARENTS_EXPR
 296 check_parents () {
 297         assert test $# = 1
 298         missed=$(cache_miss "$1") || exit $?
 299         local indent=$(($indent + 1))
 300         for miss in $missed
 301         do
 302                 if ! test -r "$cachedir/notree/$miss"
 303                 then
 304                         debug "incorrect order: $miss"
 305                         process_split_commit "$miss" ""
 306                 fi
 307         done
 308 }
 309
 310 # Usage: set_notree REV
 311 set_notree () {
 312         assert test $# = 1
 313         echo "1" > "$cachedir/notree/$1"
 314 }
 315
 316 # Usage: cache_set OLDREV NEWREV
 317 cache_set () {
 318         assert test $# = 2
 319         oldrev="$1"
 320         newrev="$2"
 321         if test "$oldrev" != "latest_old" &&
 322                 test "$oldrev" != "latest_new" &&
 323                 test -e "$cachedir/$oldrev"
 324         then
 325                 die "cache for $oldrev already exists!"
 326         fi
 327         echo "$newrev" >"$cachedir/$oldrev"
 328 }
 329
 330 # Usage: rev_exists REV
 331 rev_exists () {
 332         assert test $# = 1
 333         if git rev-parse "$1" >/dev/null 2>&1
 334         then
 335                 return 0
 336         else
 337                 return 1
 338         fi
 339 }
 340
 341 # Usage: try_remove_previous REV
 342 #
 343 # If a commit doesn't have a parent, this might not work.  But we only want
 344 # to remove the parent from the rev-list, and since it doesn't exist, it won't
 345 # be there anyway, so do nothing in that case.
 346 try_remove_previous () {
 347         assert test $# = 1
 348         if rev_exists "$1^"
 349         then
 350                 echo "^$1^"
 351         fi
 352 }
 353
 354 # Usage: find_latest_squash DIR
 355 find_latest_squash () {
 356         assert test $# = 1
 357         debug "Looking for latest squash ($dir)..."
 358         local indent=$(($indent + 1))
 359
 360         dir="$1"
 361         sq=
 362         main=
 363         sub=
 364         git log --grep="^git-subtree-dir: $dir/*\$" \
 365                 --no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' HEAD |
 366         while read a b junk
 367         do
 368                 debug "$a $b $junk"
 369                 debug "{{$sq/$main/$sub}}"
 370                 case "$a" in
 371                 START)
 372                         sq="$b"
 373                         ;;
 374                 git-subtree-mainline:)
 375                         main="$b"
 376                         ;;
 377                 git-subtree-split:)
 378                         sub="$(git rev-parse "$b^{commit}")" ||
 379                         die "could not rev-parse split hash $b from commit $sq"
 380                         ;;
 381                 END)
 382                         if test -n "$sub"
 383                         then
 384                                 if test -n "$main"
 385                                 then
 386                                         # a rejoin commit?
 387                                         # Pretend its sub was a squash.
 388                                         sq=$(git rev-parse --verify "$sq^2") ||
 389                                                 die
 390                                 fi
 391                                 debug "Squash found: $sq $sub"
 392                                 echo "$sq" "$sub"
 393                                 break
 394                         fi
 395                         sq=
 396                         main=
 397                         sub=
 398                         ;;
 399                 esac
 400         done || exit $?
 401 }
 402
 403 # Usage: find_existing_splits DIR REV
 404 find_existing_splits () {
 405         assert test $# = 2
 406         debug "Looking for prior splits..."
 407         local indent=$(($indent + 1))
 408
 409         dir="$1"
 410         rev="$2"
 411         main=
 412         sub=
 413         local grep_format="^git-subtree-dir: $dir/*\$"
 414         if test -n "$arg_split_ignore_joins"
 415         then
 416                 grep_format="^Add '$dir/' from commit '"
 417         fi
 418         git log --grep="$grep_format" \
 419                 --no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' "$rev" |
 420         while read a b junk
 421         do
 422                 case "$a" in
 423                 START)
 424                         sq="$b"
 425                         ;;
 426                 git-subtree-mainline:)
 427                         main="$b"
 428                         ;;
 429                 git-subtree-split:)
 430                         sub="$(git rev-parse "$b^{commit}")" ||
 431                         die "could not rev-parse split hash $b from commit $sq"
 432                         ;;
 433                 END)
 434                         debug "Main is: '$main'"
 435                         if test -z "$main" -a -n "$sub"
 436                         then
 437                                 # squash commits refer to a subtree
 438                                 debug "  Squash: $sq from $sub"
 439                                 cache_set "$sq" "$sub"
 440                         fi
 441                         if test -n "$main" -a -n "$sub"
 442                         then
 443                                 debug "  Prior: $main -> $sub"
 444                                 cache_set $main $sub
 445                                 cache_set $sub $sub
 446                                 try_remove_previous "$main"
 447                                 try_remove_previous "$sub"
 448                         fi
 449                         main=
 450                         sub=
 451                         ;;
 452                 esac
 453         done || exit $?
 454 }
 455
 456 # Usage: copy_commit REV TREE FLAGS_STR
 457 copy_commit () {
 458         assert test $# = 3
 459         # We're going to set some environment vars here, so
 460         # do it in a subshell to get rid of them safely later
 461         debug copy_commit "{$1}" "{$2}" "{$3}"
 462         git log -1 --no-show-signature --pretty=format:'%an%n%ae%n%aD%n%cn%n%ce%n%cD%n%B' "$1" |
 463         (
 464                 read GIT_AUTHOR_NAME
 465                 read GIT_AUTHOR_EMAIL
 466                 read GIT_AUTHOR_DATE
 467                 read GIT_COMMITTER_NAME
 468                 read GIT_COMMITTER_EMAIL
 469                 read GIT_COMMITTER_DATE
 470                 export  GIT_AUTHOR_NAME \
 471                         GIT_AUTHOR_EMAIL \
 472                         GIT_AUTHOR_DATE \
 473                         GIT_COMMITTER_NAME \
 474                         GIT_COMMITTER_EMAIL \
 475                         GIT_COMMITTER_DATE
 476                 (
 477                         printf "%s" "$arg_split_annotate"
 478                         cat
 479                 ) |
 480                 git commit-tree "$2" $3  # reads the rest of stdin
 481         ) || die "Can't copy commit $1"
 482 }
 483
 484 # Usage: add_msg DIR LATEST_OLD LATEST_NEW
 485 add_msg () {
 486         assert test $# = 3
 487         dir="$1"
 488         latest_old="$2"
 489         latest_new="$3"
 490         if test -n "$arg_addmerge_message"
 491         then
 492                 commit_message="$arg_addmerge_message"
 493         else
 494                 commit_message="Add '$dir/' from commit '$latest_new'"
 495         fi
 496         if test -n "$arg_split_rejoin"
 497         then
 498                 # If this is from a --rejoin, then rejoin_msg has
 499                 # already inserted the `git-subtree-xxx:` tags
 500                 echo "$commit_message"
 501                 return
 502         fi
 503         cat <<-EOF
 504                 $commit_message
 505
 506                 git-subtree-dir: $dir
 507                 git-subtree-mainline: $latest_old
 508                 git-subtree-split: $latest_new
 509         EOF
 510 }
 511
 512 # Usage: add_squashed_msg REV DIR
 513 add_squashed_msg () {
 514         assert test $# = 2
 515         if test -n "$arg_addmerge_message"
 516         then
 517                 echo "$arg_addmerge_message"
 518         else
 519                 echo "Merge commit '$1' as '$2'"
 520         fi
 521 }
 522
 523 # Usage: rejoin_msg DIR LATEST_OLD LATEST_NEW
 524 rejoin_msg () {
 525         assert test $# = 3
 526         dir="$1"
 527         latest_old="$2"
 528         latest_new="$3"
 529         if test -n "$arg_addmerge_message"
 530         then
 531                 commit_message="$arg_addmerge_message"
 532         else
 533                 commit_message="Split '$dir/' into commit '$latest_new'"
 534         fi
 535         cat <<-EOF
 536                 $commit_message
 537
 538                 git-subtree-dir: $dir
 539                 git-subtree-mainline: $latest_old
 540                 git-subtree-split: $latest_new
 541         EOF
 542 }
 543
 544 # Usage: squash_msg DIR OLD_SUBTREE_COMMIT NEW_SUBTREE_COMMIT
 545 squash_msg () {
 546         assert test $# = 3
 547         dir="$1"
 548         oldsub="$2"
 549         newsub="$3"
 550         newsub_short=$(git rev-parse --short "$newsub")
 551
 552         if test -n "$oldsub"
 553         then
 554                 oldsub_short=$(git rev-parse --short "$oldsub")
 555                 echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short"
 556                 echo
 557                 git log --no-show-signature --pretty=tformat:'%h %s' "$oldsub..$newsub"
 558                 git log --no-show-signature --pretty=tformat:'REVERT: %h %s' "$newsub..$oldsub"
 559         else
 560                 echo "Squashed '$dir/' content from commit $newsub_short"
 561         fi
 562
 563         echo
 564         echo "git-subtree-dir: $dir"
 565         echo "git-subtree-split: $newsub"
 566 }
 567
 568 # Usage: toptree_for_commit COMMIT
 569 toptree_for_commit () {
 570         assert test $# = 1
 571         commit="$1"
 572         git rev-parse --verify "$commit^{tree}" || exit $?
 573 }
 574
 575 # Usage: subtree_for_commit COMMIT DIR
 576 subtree_for_commit () {
 577         assert test $# = 2
 578         commit="$1"
 579         dir="$2"
 580         git ls-tree "$commit" -- "$dir" |
 581         while read mode type tree name
 582         do
 583                 assert test "$name" = "$dir"
 584                 assert test "$type" = "tree" -o "$type" = "commit"
 585                 test "$type" = "commit" && continue  # ignore submodules
 586                 echo $tree
 587                 break
 588         done || exit $?
 589 }
 590
 591 # Usage: tree_changed TREE [PARENTS...]
 592 tree_changed () {
 593         assert test $# -gt 0
 594         tree=$1
 595         shift
 596         if test $# -ne 1
 597         then
 598                 return 0   # weird parents, consider it changed
 599         else
 600                 ptree=$(toptree_for_commit $1) || exit $?
 601                 if test "$ptree" != "$tree"
 602                 then
 603                         return 0   # changed
 604                 else
 605                         return 1   # not changed
 606                 fi
 607         fi
 608 }
 609
 610 # Usage: new_squash_commit OLD_SQUASHED_COMMIT OLD_NONSQUASHED_COMMIT NEW_NONSQUASHED_COMMIT
 611 new_squash_commit () {
 612         assert test $# = 3
 613         old="$1"
 614         oldsub="$2"
 615         newsub="$3"
 616         tree=$(toptree_for_commit $newsub) || exit $?
 617         if test -n "$old"
 618         then
 619                 squash_msg "$dir" "$oldsub" "$newsub" |
 620                 git commit-tree "$tree" -p "$old" || exit $?
 621         else
 622                 squash_msg "$dir" "" "$newsub" |
 623                 git commit-tree "$tree" || exit $?
 624         fi
 625 }
 626
 627 # Usage: copy_or_skip REV TREE NEWPARENTS
 628 copy_or_skip () {
 629         assert test $# = 3
 630         rev="$1"
 631         tree="$2"
 632         newparents="$3"
 633         assert test -n "$tree"
 634
 635         identical=
 636         nonidentical=
 637         p=
 638         gotparents=
 639         copycommit=
 640         for parent in $newparents
 641         do
 642                 ptree=$(toptree_for_commit $parent) || exit $?
 643                 test -z "$ptree" && continue
 644                 if test "$ptree" = "$tree"
 645                 then
 646                         # an identical parent could be used in place of this rev.
 647                         if test -n "$identical"
 648                         then
 649                                 # if a previous identical parent was found, check whether
 650                                 # one is already an ancestor of the other
 651                                 mergebase=$(git merge-base $identical $parent)
 652                                 if test "$identical" = "$mergebase"
 653                                 then
 654                                         # current identical commit is an ancestor of parent
 655                                         identical="$parent"
 656                                 elif test "$parent" != "$mergebase"
 657                                 then
 658                                         # no common history; commit must be copied
 659                                         copycommit=1
 660                                 fi
 661                         else
 662                                 # first identical parent detected
 663                                 identical="$parent"
 664                         fi
 665                 else
 666                         nonidentical="$parent"
 667                 fi
 668
 669                 # sometimes both old parents map to the same newparent;
 670                 # eliminate duplicates
 671                 is_new=1
 672                 for gp in $gotparents
 673                 do
 674                         if test "$gp" = "$parent"
 675                         then
 676                                 is_new=
 677                                 break
 678                         fi
 679                 done
 680                 if test -n "$is_new"
 681                 then
 682                         gotparents="$gotparents $parent"
 683                         p="$p -p $parent"
 684                 fi
 685         done
 686
 687         if test -n "$identical" && test -n "$nonidentical"
 688         then
 689                 extras=$(git rev-list --count $identical..$nonidentical)
 690                 if test "$extras" -ne 0
 691                 then
 692                         # we need to preserve history along the other branch
 693                         copycommit=1
 694                 fi
 695         fi
 696         if test -n "$identical" && test -z "$copycommit"
 697         then
 698                 echo $identical
 699         else
 700                 copy_commit "$rev" "$tree" "$p" || exit $?
 701         fi
 702 }
 703
 704 # Usage: ensure_clean
 705 ensure_clean () {
 706         assert test $# = 0
 707         if ! git diff-index HEAD --exit-code --quiet 2>&1
 708         then
 709                 die "Working tree has modifications.  Cannot add."
 710         fi
 711         if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
 712         then
 713                 die "Index has modifications.  Cannot add."
 714         fi
 715 }
 716
 717 # Usage: ensure_valid_ref_format REF
 718 ensure_valid_ref_format () {
 719         assert test $# = 1
 720         git check-ref-format "refs/heads/$1" ||
 721                 die "'$1' does not look like a ref"
 722 }
 723
 724 # Usage: process_split_commit REV PARENTS
 725 process_split_commit () {
 726         assert test $# = 2
 727         local rev="$1"
 728         local parents="$2"
 729
 730         if test $indent -eq 0
 731         then
 732                 revcount=$(($revcount + 1))
 733         else
 734                 # processing commit without normal parent information;
 735                 # fetch from repo
 736                 parents=$(git rev-parse "$rev^@")
 737                 extracount=$(($extracount + 1))
 738         fi
 739
 740         progress "$revcount/$revmax ($createcount) [$extracount]"
 741
 742         debug "Processing commit: $rev"
 743         local indent=$(($indent + 1))
 744         exists=$(cache_get "$rev") || exit $?
 745         if test -n "$exists"
 746         then
 747                 debug "prior: $exists"
 748                 return
 749         fi
 750         createcount=$(($createcount + 1))
 751         debug "parents: $parents"
 752         check_parents "$parents"
 753         newparents=$(cache_get $parents) || exit $?
 754         debug "newparents: $newparents"
 755
 756         tree=$(subtree_for_commit "$rev" "$dir") || exit $?
 757         debug "tree is: $tree"
 758
 759         # ugly.  is there no better way to tell if this is a subtree
 760         # vs. a mainline commit?  Does it matter?
 761         if test -z "$tree"
 762         then
 763                 set_notree "$rev"
 764                 if test -n "$newparents"
 765                 then
 766                         cache_set "$rev" "$rev"
 767                 fi
 768                 return
 769         fi
 770
 771         newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
 772         debug "newrev is: $newrev"
 773         cache_set "$rev" "$newrev"
 774         cache_set latest_new "$newrev"
 775         cache_set latest_old "$rev"
 776 }
 777
 778 # Usage: cmd_add REV
 779 #    Or: cmd_add REPOSITORY REF
 780 cmd_add () {
 781
 782         ensure_clean
 783
 784         if test $# -eq 1
 785         then
 786                 git rev-parse -q --verify "$1^{commit}" >/dev/null ||
 787                         die "'$1' does not refer to a commit"
 788
 789                 cmd_add_commit "$@"
 790
 791         elif test $# -eq 2
 792         then
 793                 # Technically we could accept a refspec here but we're
 794                 # just going to turn around and add FETCH_HEAD under the
 795                 # specified directory.  Allowing a refspec might be
 796                 # misleading because we won't do anything with any other
 797                 # branches fetched via the refspec.
 798                 ensure_valid_ref_format "$2"
 799
 800                 cmd_add_repository "$@"
 801         else
 802                 say >&2 "error: parameters were '$*'"
 803                 die "Provide either a commit or a repository and commit."
 804         fi
 805 }
 806
 807 # Usage: cmd_add_repository REPOSITORY REFSPEC
 808 cmd_add_repository () {
 809         assert test $# = 2
 810         echo "git fetch" "$@"
 811         repository=$1
 812         refspec=$2
 813         git fetch "$@" || exit $?
 814         cmd_add_commit FETCH_HEAD
 815 }
 816
 817 # Usage: cmd_add_commit REV
 818 cmd_add_commit () {
 819         # The rev has already been validated by cmd_add(), we just
 820         # need to normalize it.
 821         assert test $# = 1
 822         rev=$(git rev-parse --verify "$1^{commit}") || exit $?
 823
 824         debug "Adding $dir as '$rev'..."
 825         if test -z "$arg_split_rejoin"
 826         then
 827                 # Only bother doing this if this is a genuine 'add',
 828                 # not a synthetic 'add' from '--rejoin'.
 829                 git read-tree --prefix="$dir" $rev || exit $?
 830         fi
 831         git checkout -- "$dir" || exit $?
 832         tree=$(git write-tree) || exit $?
 833
 834         headrev=$(git rev-parse HEAD) || exit $?
 835         if test -n "$headrev" && test "$headrev" != "$rev"
 836         then
 837                 headp="-p $headrev"
 838         else
 839                 headp=
 840         fi
 841
 842         if test -n "$arg_addmerge_squash"
 843         then
 844                 rev=$(new_squash_commit "" "" "$rev") || exit $?
 845                 commit=$(add_squashed_msg "$rev" "$dir" |
 846                         git commit-tree "$tree" $headp -p "$rev") || exit $?
 847         else
 848                 revp=$(peel_committish "$rev") || exit $?
 849                 commit=$(add_msg "$dir" $headrev "$rev" |
 850                         git commit-tree "$tree" $headp -p "$revp") || exit $?
 851         fi
 852         git reset "$commit" || exit $?
 853
 854         say >&2 "Added dir '$dir'"
 855 }
 856
 857 # Usage: cmd_split [REV]
 858 cmd_split () {
 859         if test $# -eq 0
 860         then
 861                 rev=$(git rev-parse HEAD)
 862         elif test $# -eq 1
 863         then
 864                 rev=$(git rev-parse -q --verify "$1^{commit}") ||
 865                         die "'$1' does not refer to a commit"
 866         else
 867                 die "You must provide exactly one revision.  Got: '$*'"
 868         fi
 869
 870         if test -n "$arg_split_rejoin"
 871         then
 872                 ensure_clean
 873         fi
 874
 875         debug "Splitting $dir..."
 876         cache_setup || exit $?
 877
 878         if test -n "$arg_split_onto"
 879         then
 880                 debug "Reading history for --onto=$arg_split_onto..."
 881                 git rev-list $arg_split_onto |
 882                 while read rev
 883                 do
 884                         # the 'onto' history is already just the subdir, so
 885                         # any parent we find there can be used verbatim
 886                         debug "cache: $rev"
 887                         cache_set "$rev" "$rev"
 888                 done || exit $?
 889         fi
 890
 891         unrevs="$(find_existing_splits "$dir" "$rev")" || exit $?
 892
 893         # We can't restrict rev-list to only $dir here, because some of our
 894         # parents have the $dir contents the root, and those won't match.
 895         # (and rev-list --follow doesn't seem to solve this)
 896         grl='git rev-list --topo-order --reverse --parents $rev $unrevs'
 897         revmax=$(eval "$grl" | wc -l)
 898         revcount=0
 899         createcount=0
 900         extracount=0
 901         eval "$grl" |
 902         while read rev parents
 903         do
 904                 process_split_commit "$rev" "$parents"
 905         done || exit $?
 906
 907         latest_new=$(cache_get latest_new) || exit $?
 908         if test -z "$latest_new"
 909         then
 910                 die "No new revisions were found"
 911         fi
 912
 913         if test -n "$arg_split_rejoin"
 914         then
 915                 debug "Merging split branch into HEAD..."
 916                 latest_old=$(cache_get latest_old) || exit $?
 917                 arg_addmerge_message="$(rejoin_msg "$dir" "$latest_old" "$latest_new")" || exit $?
 918                 if test -z "$(find_latest_squash "$dir")"
 919                 then
 920                         cmd_add "$latest_new" >&2 || exit $?
 921                 else
 922                         cmd_merge "$latest_new" >&2 || exit $?
 923                 fi
 924         fi
 925         if test -n "$arg_split_branch"
 926         then
 927                 if rev_exists "refs/heads/$arg_split_branch"
 928                 then
 929                         if ! git merge-base --is-ancestor "$arg_split_branch" "$latest_new"
 930                         then
 931                                 die "Branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
 932                         fi
 933                         action='Updated'
 934                 else
 935                         action='Created'
 936                 fi
 937                 git update-ref -m 'subtree split' \
 938                         "refs/heads/$arg_split_branch" "$latest_new" || exit $?
 939                 say >&2 "$action branch '$arg_split_branch'"
 940         fi
 941         echo "$latest_new"
 942         exit 0
 943 }
 944
 945 # Usage: cmd_merge REV
 946 cmd_merge () {
 947         test $# -eq 1 ||
 948                 die "You must provide exactly one revision.  Got: '$*'"
 949         rev=$(git rev-parse -q --verify "$1^{commit}") ||
 950                 die "'$1' does not refer to a commit"
 951         ensure_clean
 952
 953         if test -n "$arg_addmerge_squash"
 954         then
 955                 first_split="$(find_latest_squash "$dir")" || exit $?
 956                 if test -z "$first_split"
 957                 then
 958                         die "Can't squash-merge: '$dir' was never added."
 959                 fi
 960                 set $first_split
 961                 old=$1
 962                 sub=$2
 963                 if test "$sub" = "$rev"
 964                 then
 965                         say >&2 "Subtree is already at commit $rev."
 966                         exit 0
 967                 fi
 968                 new=$(new_squash_commit "$old" "$sub" "$rev") || exit $?
 969                 debug "New squash commit: $new"
 970                 rev="$new"
 971         fi
 972
 973         if test -n "$arg_addmerge_message"
 974         then
 975                 git merge -Xsubtree="$arg_prefix" \
 976                         --message="$arg_addmerge_message" "$rev"
 977         else
 978                 git merge -Xsubtree="$arg_prefix" $rev
 979         fi
 980 }
 981
 982 # Usage: cmd_pull REPOSITORY REMOTEREF
 983 cmd_pull () {
 984         if test $# -ne 2
 985         then
 986                 die "You must provide <repository> <ref>"
 987         fi
 988         ensure_clean
 989         ensure_valid_ref_format "$2"
 990         git fetch "$@" || exit $?
 991         cmd_merge FETCH_HEAD
 992 }
 993
 994 # Usage: cmd_push REPOSITORY [+][LOCALREV:]REMOTEREF
 995 cmd_push () {
 996         if test $# -ne 2
 997         then
 998                 die "You must provide <repository> <refspec>"
 999         fi
1000         if test -e "$dir"
1001         then
1002                 repository=$1
1003                 refspec=${2#+}
1004                 remoteref=${refspec#*:}
1005                 if test "$remoteref" = "$refspec"
1006                 then
1007                         localrevname_presplit=HEAD
1008                 else
1009                         localrevname_presplit=${refspec%%:*}
1010                 fi
1011                 ensure_valid_ref_format "$remoteref"
1012                 localrev_presplit=$(git rev-parse -q --verify "$localrevname_presplit^{commit}") ||
1013                         die "'$localrevname_presplit' does not refer to a commit"
1014
1015                 echo "git push using: " "$repository" "$refspec"
1016                 localrev=$(cmd_split "$localrev_presplit") || die
1017                 git push "$repository" "$localrev":"refs/heads/$remoteref"
1018         else
1019                 die "'$dir' must already exist. Try 'git subtree add'."
1020         fi
1021 }
1022
1023 main "$@"