Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+'
   7
   8SUBDIRECTORY_OK=Yes
   9. git-sh-setup
  10require_work_tree
  11cd_to_toplevel
  12
  13test -z "$(git ls-files -u)" ||
  14        die "You are in the middle of a conflicted merge."
  15
  16LF='
  17'
  18
  19all_strategies='recur recursive octopus resolve stupid ours'
  20default_twohead_strategies='recursive'
  21default_octopus_strategies='octopus'
  22no_trivial_merge_strategies='ours'
  23use_strategies=
  24
  25index_merge=t
  26
  27dropsave() {
  28        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  29                 "$GIT_DIR/MERGE_SAVE" || exit 1
  30}
  31
  32savestate() {
  33        # Stash away any local modifications.
  34        git-diff-index -z --name-only $head |
  35        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  36}
  37
  38restorestate() {
  39        if test -f "$GIT_DIR/MERGE_SAVE"
  40        then
  41                git reset --hard $head >/dev/null
  42                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  43                git-update-index --refresh >/dev/null
  44        fi
  45}
  46
  47finish_up_to_date () {
  48        case "$squash" in
  49        t)
  50                echo "$1 (nothing to squash)" ;;
  51        '')
  52                echo "$1" ;;
  53        esac
  54        dropsave
  55}
  56
  57squash_message () {
  58        echo Squashed commit of the following:
  59        echo
  60        git-log --no-merges ^"$head" $remote
  61}
  62
  63finish () {
  64        if test '' = "$2"
  65        then
  66                rlogm="$GIT_REFLOG_ACTION"
  67        else
  68                echo "$2"
  69                rlogm="$GIT_REFLOG_ACTION: $2"
  70        fi
  71        case "$squash" in
  72        t)
  73                echo "Squash commit -- not updating HEAD"
  74                squash_message >"$GIT_DIR/SQUASH_MSG"
  75                ;;
  76        '')
  77                case "$merge_msg" in
  78                '')
  79                        echo "No merge message -- not updating HEAD"
  80                        ;;
  81                *)
  82                        git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
  83                        ;;
  84                esac
  85                ;;
  86        esac
  87        case "$1" in
  88        '')
  89                ;;
  90        ?*)
  91                case "$no_summary" in
  92                '')
  93                        git-diff-tree --stat --summary -M "$head" "$1"
  94                        ;;
  95                esac
  96                ;;
  97        esac
  98}
  99
 100merge_name () {
 101        remote="$1"
 102        rh=$(git-rev-parse --verify "$remote^0" 2>/dev/null) || return
 103        bh=$(git-show-ref -s --verify "refs/heads/$remote" 2>/dev/null)
 104        if test "$rh" = "$bh"
 105        then
 106                echo "$rh               branch '$remote' of ."
 107        elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') &&
 108                git-show-ref -q --verify "refs/heads/$truname" 2>/dev/null
 109        then
 110                echo "$rh               branch '$truname' (early part) of ."
 111        else
 112                echo "$rh               commit '$remote'"
 113        fi
 114}
 115
 116case "$#" in 0) usage ;; esac
 117
 118have_message=
 119while case "$#" in 0) break ;; esac
 120do
 121        case "$1" in
 122        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 123                --no-summa|--no-summar|--no-summary)
 124                no_summary=t ;;
 125        --sq|--squ|--squa|--squas|--squash)
 126                squash=t no_commit=t ;;
 127        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 128                no_commit=t ;;
 129        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 130                --strateg=*|--strategy=*|\
 131        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 132                case "$#,$1" in
 133                *,*=*)
 134                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 135                1,*)
 136                        usage ;;
 137                *)
 138                        strategy="$2"
 139                        shift ;;
 140                esac
 141                case " $all_strategies " in
 142                *" $strategy "*)
 143                        use_strategies="$use_strategies$strategy " ;;
 144                *)
 145                        die "available strategies are: $all_strategies" ;;
 146                esac
 147                ;;
 148        -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
 149                merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 150                have_message=t
 151                ;;
 152        -m|--m|--me|--mes|--mess|--messa|--messag|--message)
 153                shift
 154                case "$#" in
 155                1)      usage ;;
 156                esac
 157                merge_msg="$1"
 158                have_message=t
 159                ;;
 160        -*)     usage ;;
 161        *)      break ;;
 162        esac
 163        shift
 164done
 165
 166# This could be traditional "merge <msg> HEAD <commit>..."  and the
 167# way we can tell it is to see if the second token is HEAD, but some
 168# people might have misused the interface and used a committish that
 169# is the same as HEAD there instead.  Traditional format never would
 170# have "-m" so it is an additional safety measure to check for it.
 171
 172if test -z "$have_message" &&
 173        second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
 174        head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
 175        test "$second_token" = "$head_commit"
 176then
 177        merge_msg="$1"
 178        shift
 179        head_arg="$1"
 180        shift
 181elif ! git-rev-parse --verify HEAD >/dev/null 2>&1
 182then
 183        # If the merged head is a valid one there is no reason to
 184        # forbid "git merge" into a branch yet to be born.  We do
 185        # the same for "git pull".
 186        if test 1 -ne $#
 187        then
 188                echo >&2 "Can merge only exactly one commit into empty head"
 189                exit 1
 190        fi
 191
 192        rh=$(git rev-parse --verify "$1^0") ||
 193                die "$1 - not something we can merge"
 194
 195        git-update-ref -m "initial pull" HEAD "$rh" "" &&
 196        git-read-tree --reset -u HEAD
 197        exit
 198
 199else
 200        # We are invoked directly as the first-class UI.
 201        head_arg=HEAD
 202
 203        # All the rest are the commits being merged; prepare
 204        # the standard merge summary message to be appended to
 205        # the given message.  If remote is invalid we will die
 206        # later in the common codepath so we discard the error
 207        # in this loop.
 208        merge_name=$(for remote
 209                do
 210                        merge_name "$remote"
 211                done | git-fmt-merge-msg
 212        )
 213        merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 214fi
 215head=$(git-rev-parse --verify "$head_arg"^0) || usage
 216
 217# All the rest are remote heads
 218test "$#" = 0 && usage ;# we need at least one remote head.
 219set_reflog_action "merge $*"
 220
 221remoteheads=
 222for remote
 223do
 224        remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) ||
 225            die "$remote - not something we can merge"
 226        remoteheads="${remoteheads}$remotehead "
 227        eval GITHEAD_$remotehead='"$remote"'
 228        export GITHEAD_$remotehead
 229done
 230set x $remoteheads ; shift
 231
 232case "$use_strategies" in
 233'')
 234        case "$#" in
 235        1)
 236                var="`git-config --get pull.twohead`"
 237                if test -n "$var"
 238                then
 239                        use_strategies="$var"
 240                else
 241                        use_strategies="$default_twohead_strategies"
 242                fi ;;
 243        *)
 244                var="`git-config --get pull.octopus`"
 245                if test -n "$var"
 246                then
 247                        use_strategies="$var"
 248                else
 249                        use_strategies="$default_octopus_strategies"
 250                fi ;;
 251        esac
 252        ;;
 253esac
 254
 255for s in $use_strategies
 256do
 257        for nt in $no_trivial_merge_strategies
 258        do
 259                case " $s " in
 260                *" $nt "*)
 261                        index_merge=f
 262                        break
 263                        ;;
 264                esac
 265        done
 266done
 267
 268case "$#" in
 2691)
 270        common=$(git-merge-base --all $head "$@")
 271        ;;
 272*)
 273        common=$(git-show-branch --merge-base $head "$@")
 274        ;;
 275esac
 276echo "$head" >"$GIT_DIR/ORIG_HEAD"
 277
 278case "$index_merge,$#,$common,$no_commit" in
 279f,*)
 280        # We've been told not to try anything clever.  Skip to real merge.
 281        ;;
 282?,*,'',*)
 283        # No common ancestors found. We need a real merge.
 284        ;;
 285?,1,"$1",*)
 286        # If head can reach all the merge then we are up to date.
 287        # but first the most common case of merging one remote.
 288        finish_up_to_date "Already up-to-date."
 289        exit 0
 290        ;;
 291?,1,"$head",*)
 292        # Again the most common case of merging one remote.
 293        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 294        git-update-index --refresh 2>/dev/null
 295        msg="Fast forward"
 296        if test -n "$have_message"
 297        then
 298                msg="$msg (no commit created; -m option ignored)"
 299        fi
 300        new_head=$(git-rev-parse --verify "$1^0") &&
 301        git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 302        finish "$new_head" "$msg" || exit
 303        dropsave
 304        exit 0
 305        ;;
 306?,1,?*"$LF"?*,*)
 307        # We are not doing octopus and not fast forward.  Need a
 308        # real merge.
 309        ;;
 310?,1,*,)
 311        # We are not doing octopus, not fast forward, and have only
 312        # one common.
 313        git-update-index --refresh 2>/dev/null
 314        case " $use_strategies " in
 315        *' recursive '*|*' recur '*)
 316                : run merge later
 317                ;;
 318        *)
 319                # See if it is really trivial.
 320                git var GIT_COMMITTER_IDENT >/dev/null || exit
 321                echo "Trying really trivial in-index merge..."
 322                if git-read-tree --trivial -m -u -v $common $head "$1" &&
 323                   result_tree=$(git-write-tree)
 324                then
 325                        echo "Wonderful."
 326                        result_commit=$(
 327                                echo "$merge_msg" |
 328                                git-commit-tree $result_tree -p HEAD -p "$1"
 329                        ) || exit
 330                        finish "$result_commit" "In-index merge"
 331                        dropsave
 332                        exit 0
 333                fi
 334                echo "Nope."
 335        esac
 336        ;;
 337*)
 338        # An octopus.  If we can reach all the remote we are up to date.
 339        up_to_date=t
 340        for remote
 341        do
 342                common_one=$(git-merge-base --all $head $remote)
 343                if test "$common_one" != "$remote"
 344                then
 345                        up_to_date=f
 346                        break
 347                fi
 348        done
 349        if test "$up_to_date" = t
 350        then
 351                finish_up_to_date "Already up-to-date. Yeeah!"
 352                exit 0
 353        fi
 354        ;;
 355esac
 356
 357# We are going to make a new commit.
 358git var GIT_COMMITTER_IDENT >/dev/null || exit
 359
 360# At this point, we need a real merge.  No matter what strategy
 361# we use, it would operate on the index, possibly affecting the
 362# working tree, and when resolved cleanly, have the desired tree
 363# in the index -- this means that the index must be in sync with
 364# the $head commit.  The strategies are responsible to ensure this.
 365
 366case "$use_strategies" in
 367?*' '?*)
 368    # Stash away the local changes so that we can try more than one.
 369    savestate
 370    single_strategy=no
 371    ;;
 372*)
 373    rm -f "$GIT_DIR/MERGE_SAVE"
 374    single_strategy=yes
 375    ;;
 376esac
 377
 378result_tree= best_cnt=-1 best_strategy= wt_strategy=
 379merge_was_ok=
 380for strategy in $use_strategies
 381do
 382    test "$wt_strategy" = '' || {
 383        echo "Rewinding the tree to pristine..."
 384        restorestate
 385    }
 386    case "$single_strategy" in
 387    no)
 388        echo "Trying merge strategy $strategy..."
 389        ;;
 390    esac
 391
 392    # Remember which strategy left the state in the working tree
 393    wt_strategy=$strategy
 394
 395    git-merge-$strategy $common -- "$head_arg" "$@"
 396    exit=$?
 397    if test "$no_commit" = t && test "$exit" = 0
 398    then
 399        merge_was_ok=t
 400        exit=1 ;# pretend it left conflicts.
 401    fi
 402
 403    test "$exit" = 0 || {
 404
 405        # The backend exits with 1 when conflicts are left to be resolved,
 406        # with 2 when it does not handle the given merge at all.
 407
 408        if test "$exit" -eq 1
 409        then
 410            cnt=`{
 411                git-diff-files --name-only
 412                git-ls-files --unmerged
 413            } | wc -l`
 414            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 415            then
 416                best_strategy=$strategy
 417                best_cnt=$cnt
 418            fi
 419        fi
 420        continue
 421    }
 422
 423    # Automerge succeeded.
 424    result_tree=$(git-write-tree) && break
 425done
 426
 427# If we have a resulting tree, that means the strategy module
 428# auto resolved the merge cleanly.
 429if test '' != "$result_tree"
 430then
 431    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 432    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 433    finish "$result_commit" "Merge made by $wt_strategy."
 434    dropsave
 435    exit 0
 436fi
 437
 438# Pick the result from the best strategy and have the user fix it up.
 439case "$best_strategy" in
 440'')
 441        restorestate
 442        case "$use_strategies" in
 443        ?*' '?*)
 444                echo >&2 "No merge strategy handled the merge."
 445                ;;
 446        *)
 447                echo >&2 "Merge with strategy $use_strategies failed."
 448                ;;
 449        esac
 450        exit 2
 451        ;;
 452"$wt_strategy")
 453        # We already have its result in the working tree.
 454        ;;
 455*)
 456        echo "Rewinding the tree to pristine..."
 457        restorestate
 458        echo "Using the $best_strategy to prepare resolving by hand."
 459        git-merge-$best_strategy $common -- "$head_arg" "$@"
 460        ;;
 461esac
 462
 463if test "$squash" = t
 464then
 465        finish
 466else
 467        for remote
 468        do
 469                echo $remote
 470        done >"$GIT_DIR/MERGE_HEAD"
 471        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 472fi
 473
 474if test "$merge_was_ok" = t
 475then
 476        echo >&2 \
 477        "Automatic merge went well; stopped before committing as requested"
 478        exit 0
 479else
 480        {
 481            echo '
 482Conflicts:
 483'
 484                git ls-files --unmerged |
 485                sed -e 's/^[^   ]*      /       /' |
 486                uniq
 487        } >>"$GIT_DIR/MERGE_MSG"
 488        if test -d "$GIT_DIR/rr-cache"
 489        then
 490                git-rerere
 491        fi
 492        die "Automatic merge failed; fix conflicts and then commit the result."
 493fi