git.oblomov.eu Git - git/blob - contrib/examples/git-merge.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano
   4 #
   5
   6 OPTIONS_KEEPDASHDASH=
   7 OPTIONS_SPEC="\
   8 git merge [options] <remote>...
   9 git merge [options] <msg> HEAD <remote>
  10 --
  11 stat                 show a diffstat at the end of the merge
  12 n                    don't show a diffstat at the end of the merge
  13 summary              (synonym to --stat)
  14 log                  add list of one-line log to merge commit message
  15 squash               create a single commit instead of doing a merge
  16 commit               perform a commit if the merge succeeds (default)
  17 ff                   allow fast-forward (default)
  18 s,strategy=          merge strategy to use
  19 X=                   option for selected merge strategy
  20 m,message=           message to be used for the merge commit (if any)
  21 "
  22
  23 SUBDIRECTORY_OK=Yes
  24 . git-sh-setup
  25 require_work_tree
  26 cd_to_toplevel
  27
  28 test -z "$(git ls-files -u)" ||
  29         die "Merge is not possible because you have unmerged files."
  30
  31 ! test -e "$GIT_DIR/MERGE_HEAD" ||
  32         die 'You have not concluded your merge (MERGE_HEAD exists).'
  33
  34 LF='
  35 '
  36
  37 all_strategies='recur recursive octopus resolve stupid ours subtree'
  38 all_strategies="$all_strategies recursive-ours recursive-theirs"
  39 default_twohead_strategies='recursive'
  40 default_octopus_strategies='octopus'
  41 no_fast_forward_strategies='subtree ours'
  42 no_trivial_strategies='recursive recur subtree ours recursive-ours recursive-theirs'
  43 use_strategies=
  44 xopt=
  45
  46 allow_fast_forward=t
  47 allow_trivial_merge=t
  48 squash= no_commit= log_arg=
  49
  50 dropsave() {
  51         rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  52                  "$GIT_DIR/MERGE_STASH" || exit 1
  53 }
  54
  55 savestate() {
  56         # Stash away any local modifications.
  57         git stash create >"$GIT_DIR/MERGE_STASH"
  58 }
  59
  60 restorestate() {
  61         if test -f "$GIT_DIR/MERGE_STASH"
  62         then
  63                 git reset --hard $head >/dev/null
  64                 git stash apply $(cat "$GIT_DIR/MERGE_STASH")
  65                 git update-index --refresh >/dev/null
  66         fi
  67 }
  68
  69 finish_up_to_date () {
  70         case "$squash" in
  71         t)
  72                 echo "$1 (nothing to squash)" ;;
  73         '')
  74                 echo "$1" ;;
  75         esac
  76         dropsave
  77 }
  78
  79 squash_message () {
  80         echo Squashed commit of the following:
  81         echo
  82         git log --no-merges --pretty=medium ^"$head" $remoteheads
  83 }
  84
  85 finish () {
  86         if test '' = "$2"
  87         then
  88                 rlogm="$GIT_REFLOG_ACTION"
  89         else
  90                 echo "$2"
  91                 rlogm="$GIT_REFLOG_ACTION: $2"
  92         fi
  93         case "$squash" in
  94         t)
  95                 echo "Squash commit -- not updating HEAD"
  96                 squash_message >"$GIT_DIR/SQUASH_MSG"
  97                 ;;
  98         '')
  99                 case "$merge_msg" in
 100                 '')
 101                         echo "No merge message -- not updating HEAD"
 102                         ;;
 103                 *)
 104                         git update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
 105                         git gc --auto
 106                         ;;
 107                 esac
 108                 ;;
 109         esac
 110         case "$1" in
 111         '')
 112                 ;;
 113         ?*)
 114                 if test "$show_diffstat" = t
 115                 then
 116                         # We want color (if set), but no pager
 117                         GIT_PAGER='' git diff --stat --summary -M "$head" "$1"
 118                 fi
 119                 ;;
 120         esac
 121
 122         # Run a post-merge hook
 123         if test -x "$GIT_DIR"/hooks/post-merge
 124         then
 125             case "$squash" in
 126             t)
 127                 "$GIT_DIR"/hooks/post-merge 1
 128                 ;;
 129             '')
 130                 "$GIT_DIR"/hooks/post-merge 0
 131                 ;;
 132             esac
 133         fi
 134 }
 135
 136 merge_name () {
 137         remote="$1"
 138         rh=$(git rev-parse --verify "$remote^0" 2>/dev/null) || return
 139         if truname=$(expr "$remote" : '\(.*\)~[0-9]*$') &&
 140                 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null
 141         then
 142                 echo "$rh               branch '$truname' (early part) of ."
 143                 return
 144         fi
 145         if found_ref=$(git rev-parse --symbolic-full-name --verify \
 146                                                         "$remote" 2>/dev/null)
 147         then
 148                 if test "${found_ref#refs/heads/}" != "$found_ref"
 149                 then
 150                         echo "$rh               branch '$remote' of ."
 151                         return
 152                 elif test "${found_ref#refs/remotes/}" != "$found_ref"
 153                 then
 154                         echo "$rh               remote branch '$remote' of ."
 155                         return
 156                 fi
 157         fi
 158         if test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD"
 159         then
 160                 sed -e 's/      not-for-merge   /               /' -e 1q \
 161                         "$GIT_DIR/FETCH_HEAD"
 162                 return
 163         fi
 164         echo "$rh               commit '$remote'"
 165 }
 166
 167 parse_config () {
 168         while test $# != 0; do
 169                 case "$1" in
 170                 -n|--no-stat|--no-summary)
 171                         show_diffstat=false ;;
 172                 --stat|--summary)
 173                         show_diffstat=t ;;
 174                 --log|--no-log)
 175                         log_arg=$1 ;;
 176                 --squash)
 177                         test "$allow_fast_forward" = t ||
 178                                 die "You cannot combine --squash with --no-ff."
 179                         squash=t no_commit=t ;;
 180                 --no-squash)
 181                         squash= no_commit= ;;
 182                 --commit)
 183                         no_commit= ;;
 184                 --no-commit)
 185                         no_commit=t ;;
 186                 --ff)
 187                         allow_fast_forward=t ;;
 188                 --no-ff)
 189                         test "$squash" != t ||
 190                                 die "You cannot combine --squash with --no-ff."
 191                         allow_fast_forward=f ;;
 192                 -s|--strategy)
 193                         shift
 194                         case " $all_strategies " in
 195                         *" $1 "*)
 196                                 use_strategies="$use_strategies$1 "
 197                                 ;;
 198                         *)
 199                                 type "git-merge-$1" >/dev/null 2>&1 ||
 200                                         die "available strategies are: $all_strategies"
 201                                 use_strategies="$use_strategies$1 "
 202                                 ;;
 203                         esac
 204                         ;;
 205                 -X)
 206                         shift
 207                         xopt="${xopt:+$xopt }$(git rev-parse --sq-quote "--$1")"
 208                         ;;
 209                 -m|--message)
 210                         shift
 211                         merge_msg="$1"
 212                         have_message=t
 213                         ;;
 214                 --)
 215                         shift
 216                         break ;;
 217                 *)      usage ;;
 218                 esac
 219                 shift
 220         done
 221         args_left=$#
 222 }
 223
 224 test $# != 0 || usage
 225
 226 have_message=
 227
 228 if branch=$(git-symbolic-ref -q HEAD)
 229 then
 230         mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions")
 231         if test -n "$mergeopts"
 232         then
 233                 parse_config $mergeopts --
 234         fi
 235 fi
 236
 237 parse_config "$@"
 238 while test $args_left -lt $#; do shift; done
 239
 240 if test -z "$show_diffstat"; then
 241     test "$(git config --bool merge.diffstat)" = false && show_diffstat=false
 242     test "$(git config --bool merge.stat)" = false && show_diffstat=false
 243     test -z "$show_diffstat" && show_diffstat=t
 244 fi
 245
 246 # This could be traditional "merge <msg> HEAD <commit>..."  and the
 247 # way we can tell it is to see if the second token is HEAD, but some
 248 # people might have misused the interface and used a committish that
 249 # is the same as HEAD there instead.  Traditional format never would
 250 # have "-m" so it is an additional safety measure to check for it.
 251
 252 if test -z "$have_message" &&
 253         second_token=$(git rev-parse --verify "$2^0" 2>/dev/null) &&
 254         head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null) &&
 255         test "$second_token" = "$head_commit"
 256 then
 257         merge_msg="$1"
 258         shift
 259         head_arg="$1"
 260         shift
 261 elif ! git rev-parse --verify HEAD >/dev/null 2>&1
 262 then
 263         # If the merged head is a valid one there is no reason to
 264         # forbid "git merge" into a branch yet to be born.  We do
 265         # the same for "git pull".
 266         if test 1 -ne $#
 267         then
 268                 echo >&2 "Can merge only exactly one commit into empty head"
 269                 exit 1
 270         fi
 271
 272         test "$squash" != t ||
 273                 die "Squash commit into empty head not supported yet"
 274         test "$allow_fast_forward" = t ||
 275                 die "Non-fast-forward into an empty head does not make sense"
 276         rh=$(git rev-parse --verify "$1^0") ||
 277                 die "$1 - not something we can merge"
 278
 279         git update-ref -m "initial pull" HEAD "$rh" "" &&
 280         git read-tree --reset -u HEAD
 281         exit
 282
 283 else
 284         # We are invoked directly as the first-class UI.
 285         head_arg=HEAD
 286
 287         # All the rest are the commits being merged; prepare
 288         # the standard merge summary message to be appended to
 289         # the given message.  If remote is invalid we will die
 290         # later in the common codepath so we discard the error
 291         # in this loop.
 292         merge_name=$(for remote
 293                 do
 294                         merge_name "$remote"
 295                 done | git fmt-merge-msg $log_arg
 296         )
 297         merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 298 fi
 299 head=$(git rev-parse --verify "$head_arg"^0) || usage
 300
 301 # All the rest are remote heads
 302 test "$#" = 0 && usage ;# we need at least one remote head.
 303 set_reflog_action "merge $*"
 304
 305 remoteheads=
 306 for remote
 307 do
 308         remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null) ||
 309             die "$remote - not something we can merge"
 310         remoteheads="${remoteheads}$remotehead "
 311         eval GITHEAD_$remotehead='"$remote"'
 312         export GITHEAD_$remotehead
 313 done
 314 set x $remoteheads ; shift
 315
 316 case "$use_strategies" in
 317 '')
 318         case "$#" in
 319         1)
 320                 var="`git config --get pull.twohead`"
 321                 if test -n "$var"
 322                 then
 323                         use_strategies="$var"
 324                 else
 325                         use_strategies="$default_twohead_strategies"
 326                 fi ;;
 327         *)
 328                 var="`git config --get pull.octopus`"
 329                 if test -n "$var"
 330                 then
 331                         use_strategies="$var"
 332                 else
 333                         use_strategies="$default_octopus_strategies"
 334                 fi ;;
 335         esac
 336         ;;
 337 esac
 338
 339 for s in $use_strategies
 340 do
 341         for ss in $no_fast_forward_strategies
 342         do
 343                 case " $s " in
 344                 *" $ss "*)
 345                         allow_fast_forward=f
 346                         break
 347                         ;;
 348                 esac
 349         done
 350         for ss in $no_trivial_strategies
 351         do
 352                 case " $s " in
 353                 *" $ss "*)
 354                         allow_trivial_merge=f
 355                         break
 356                         ;;
 357                 esac
 358         done
 359 done
 360
 361 case "$#" in
 362 1)
 363         common=$(git merge-base --all $head "$@")
 364         ;;
 365 *)
 366         common=$(git show-branch --merge-base $head "$@")
 367         ;;
 368 esac
 369 echo "$head" >"$GIT_DIR/ORIG_HEAD"
 370
 371 case "$allow_fast_forward,$#,$common,$no_commit" in
 372 ?,*,'',*)
 373         # No common ancestors found. We need a real merge.
 374         ;;
 375 ?,1,"$1",*)
 376         # If head can reach all the merge then we are up to date.
 377         # but first the most common case of merging one remote.
 378         finish_up_to_date "Already up-to-date."
 379         exit 0
 380         ;;
 381 t,1,"$head",*)
 382         # Again the most common case of merging one remote.
 383         echo "Updating $(git rev-parse --short $head)..$(git rev-parse --short $1)"
 384         git update-index --refresh 2>/dev/null
 385         msg="Fast-forward"
 386         if test -n "$have_message"
 387         then
 388                 msg="$msg (no commit created; -m option ignored)"
 389         fi
 390         new_head=$(git rev-parse --verify "$1^0") &&
 391         git read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 392         finish "$new_head" "$msg" || exit
 393         dropsave
 394         exit 0
 395         ;;
 396 ?,1,?*"$LF"?*,*)
 397         # We are not doing octopus and not fast-forward.  Need a
 398         # real merge.
 399         ;;
 400 ?,1,*,)
 401         # We are not doing octopus, not fast-forward, and have only
 402         # one common.
 403         git update-index --refresh 2>/dev/null
 404         case "$allow_trivial_merge" in
 405         t)
 406                 # See if it is really trivial.
 407                 git var GIT_COMMITTER_IDENT >/dev/null || exit
 408                 echo "Trying really trivial in-index merge..."
 409                 if git read-tree --trivial -m -u -v $common $head "$1" &&
 410                    result_tree=$(git write-tree)
 411                 then
 412                         echo "Wonderful."
 413                         result_commit=$(
 414                                 printf '%s\n' "$merge_msg" |
 415                                 git commit-tree $result_tree -p HEAD -p "$1"
 416                         ) || exit
 417                         finish "$result_commit" "In-index merge"
 418                         dropsave
 419                         exit 0
 420                 fi
 421                 echo "Nope."
 422         esac
 423         ;;
 424 *)
 425         # An octopus.  If we can reach all the remote we are up to date.
 426         up_to_date=t
 427         for remote
 428         do
 429                 common_one=$(git merge-base --all $head $remote)
 430                 if test "$common_one" != "$remote"
 431                 then
 432                         up_to_date=f
 433                         break
 434                 fi
 435         done
 436         if test "$up_to_date" = t
 437         then
 438                 finish_up_to_date "Already up-to-date. Yeeah!"
 439                 exit 0
 440         fi
 441         ;;
 442 esac
 443
 444 # We are going to make a new commit.
 445 git var GIT_COMMITTER_IDENT >/dev/null || exit
 446
 447 # At this point, we need a real merge.  No matter what strategy
 448 # we use, it would operate on the index, possibly affecting the
 449 # working tree, and when resolved cleanly, have the desired tree
 450 # in the index -- this means that the index must be in sync with
 451 # the $head commit.  The strategies are responsible to ensure this.
 452
 453 case "$use_strategies" in
 454 ?*' '?*)
 455     # Stash away the local changes so that we can try more than one.
 456     savestate
 457     single_strategy=no
 458     ;;
 459 *)
 460     rm -f "$GIT_DIR/MERGE_STASH"
 461     single_strategy=yes
 462     ;;
 463 esac
 464
 465 result_tree= best_cnt=-1 best_strategy= wt_strategy=
 466 merge_was_ok=
 467 for strategy in $use_strategies
 468 do
 469     test "$wt_strategy" = '' || {
 470         echo "Rewinding the tree to pristine..."
 471         restorestate
 472     }
 473     case "$single_strategy" in
 474     no)
 475         echo "Trying merge strategy $strategy..."
 476         ;;
 477     esac
 478
 479     # Remember which strategy left the state in the working tree
 480     wt_strategy=$strategy
 481
 482     eval 'git-merge-$strategy '"$xopt"' $common -- "$head_arg" "$@"'
 483     exit=$?
 484     if test "$no_commit" = t && test "$exit" = 0
 485     then
 486         merge_was_ok=t
 487         exit=1 ;# pretend it left conflicts.
 488     fi
 489
 490     test "$exit" = 0 || {
 491
 492         # The backend exits with 1 when conflicts are left to be resolved,
 493         # with 2 when it does not handle the given merge at all.
 494
 495         if test "$exit" -eq 1
 496         then
 497             cnt=`{
 498                 git diff-files --name-only
 499                 git ls-files --unmerged
 500             } | wc -l`
 501             if test $best_cnt -le 0 -o $cnt -le $best_cnt
 502             then
 503                 best_strategy=$strategy
 504                 best_cnt=$cnt
 505             fi
 506         fi
 507         continue
 508     }
 509
 510     # Automerge succeeded.
 511     result_tree=$(git write-tree) && break
 512 done
 513
 514 # If we have a resulting tree, that means the strategy module
 515 # auto resolved the merge cleanly.
 516 if test '' != "$result_tree"
 517 then
 518     if test "$allow_fast_forward" = "t"
 519     then
 520         parents=$(git show-branch --independent "$head" "$@")
 521     else
 522         parents=$(git rev-parse "$head" "$@")
 523     fi
 524     parents=$(echo "$parents" | sed -e 's/^/-p /')
 525     result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents) || exit
 526     finish "$result_commit" "Merge made by $wt_strategy."
 527     dropsave
 528     exit 0
 529 fi
 530
 531 # Pick the result from the best strategy and have the user fix it up.
 532 case "$best_strategy" in
 533 '')
 534         restorestate
 535         case "$use_strategies" in
 536         ?*' '?*)
 537                 echo >&2 "No merge strategy handled the merge."
 538                 ;;
 539         *)
 540                 echo >&2 "Merge with strategy $use_strategies failed."
 541                 ;;
 542         esac
 543         exit 2
 544         ;;
 545 "$wt_strategy")
 546         # We already have its result in the working tree.
 547         ;;
 548 *)
 549         echo "Rewinding the tree to pristine..."
 550         restorestate
 551         echo "Using the $best_strategy to prepare resolving by hand."
 552         git-merge-$best_strategy $common -- "$head_arg" "$@"
 553         ;;
 554 esac
 555
 556 if test "$squash" = t
 557 then
 558         finish
 559 else
 560         for remote
 561         do
 562                 echo $remote
 563         done >"$GIT_DIR/MERGE_HEAD"
 564         printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 565 fi
 566
 567 if test "$merge_was_ok" = t
 568 then
 569         echo >&2 \
 570         "Automatic merge went well; stopped before committing as requested"
 571         exit 0
 572 else
 573         {
 574             echo '
 575 Conflicts:
 576 '
 577                 git ls-files --unmerged |
 578                 sed -e 's/^[^   ]*      /       /' |
 579                 uniq
 580         } >>"$GIT_DIR/MERGE_MSG"
 581         git rerere
 582         die "Automatic merge failed; fix conflicts and then commit the result."
 583 fi