Andrew's git - gitweb.git/blob

25deb1e867ec01c65d223733a22edd98f18e241c
   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [--reflog-action=<action>] [-m=<merge-message>] <commit>+'
   7
   8. git-sh-setup
   9
  10LF='
  11'
  12
  13all_strategies='recur recursive octopus resolve stupid ours'
  14default_twohead_strategies='recursive'
  15default_octopus_strategies='octopus'
  16no_trivial_merge_strategies='ours'
  17use_strategies=
  18
  19index_merge=t
  20
  21dropsave() {
  22        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  23                 "$GIT_DIR/MERGE_SAVE" || exit 1
  24}
  25
  26savestate() {
  27        # Stash away any local modifications.
  28        git-diff-index -z --name-only $head |
  29        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  30}
  31
  32restorestate() {
  33        if test -f "$GIT_DIR/MERGE_SAVE"
  34        then
  35                git reset --hard $head
  36                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  37                git-update-index --refresh >/dev/null
  38        fi
  39}
  40
  41finish_up_to_date () {
  42        case "$squash" in
  43        t)
  44                echo "$1 (nothing to squash)" ;;
  45        '')
  46                echo "$1" ;;
  47        esac
  48        dropsave
  49}
  50
  51squash_message () {
  52        echo Squashed commit of the following:
  53        echo
  54        git-log --no-merges ^"$head" $remote
  55}
  56
  57finish () {
  58        if test '' = "$2"
  59        then
  60                rlogm="$rloga"
  61        else
  62                echo "$2"
  63                rlogm="$rloga: $2"
  64        fi
  65        case "$squash" in
  66        t)
  67                echo "Squash commit -- not updating HEAD"
  68                squash_message >"$GIT_DIR/SQUASH_MSG"
  69                ;;
  70        '')
  71                case "$merge_msg" in
  72                '')
  73                        echo "No merge message -- not updating HEAD"
  74                        ;;
  75                *)
  76                        git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
  77                        ;;
  78                esac
  79                ;;
  80        esac
  81        case "$1" in
  82        '')
  83                ;;
  84        ?*)
  85                case "$no_summary" in
  86                '')
  87                        git-diff-tree --stat --summary -M "$head" "$1"
  88                        ;;
  89                esac
  90                ;;
  91        esac
  92}
  93
  94case "$#" in 0) usage ;; esac
  95
  96rloga= have_message=
  97while case "$#" in 0) break ;; esac
  98do
  99        case "$1" in
 100        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 101                --no-summa|--no-summar|--no-summary)
 102                no_summary=t ;;
 103        --sq|--squ|--squa|--squas|--squash)
 104                squash=t no_commit=t ;;
 105        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 106                no_commit=t ;;
 107        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 108                --strateg=*|--strategy=*|\
 109        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 110                case "$#,$1" in
 111                *,*=*)
 112                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 113                1,*)
 114                        usage ;;
 115                *)
 116                        strategy="$2"
 117                        shift ;;
 118                esac
 119                case " $all_strategies " in
 120                *" $strategy "*)
 121                        use_strategies="$use_strategies$strategy " ;;
 122                *)
 123                        die "available strategies are: $all_strategies" ;;
 124                esac
 125                ;;
 126        --reflog-action=*)
 127                rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 128                ;;
 129        -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
 130                merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 131                have_message=t
 132                ;;
 133        -m|--m|--me|--mes|--mess|--messa|--messag|--message)
 134                shift
 135                case "$#" in
 136                1)      usage ;;
 137                esac
 138                merge_msg="$1"
 139                have_message=t
 140                ;;
 141        -*)     usage ;;
 142        *)      break ;;
 143        esac
 144        shift
 145done
 146
 147# This could be traditional "merge <msg> HEAD <commit>..."  and the
 148# way we can tell it is to see if the second token is HEAD, but some
 149# people might have misused the interface and used a committish that
 150# is the same as HEAD there instead.  Traditional format never would
 151# have "-m" so it is an additional safety measure to check for it.
 152
 153if test -z "$have_message" &&
 154        second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
 155        head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
 156        test "$second_token" = "$head_commit"
 157then
 158        merge_msg="$1"
 159        shift
 160        head_arg="$1"
 161        shift
 162else
 163        # We are invoked directly as the first-class UI.
 164        head_arg=HEAD
 165
 166        # All the rest are the commits being merged; prepare
 167        # the standard merge summary message to be appended to
 168        # the given message.  If remote is invalid we will die
 169        # later in the common codepath so we discard the error
 170        # in this loop.
 171        merge_name=$(for remote
 172                do
 173                        rh=$(git-rev-parse --verify "$remote"^0 2>/dev/null)
 174                        if git show-ref -q --verify "refs/heads/$remote"
 175                        then
 176                                what=branch
 177                        else
 178                                what=commit
 179                        fi
 180                        echo "$rh               $what '$remote'"
 181                done | git-fmt-merge-msg
 182        )
 183        merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 184fi
 185head=$(git-rev-parse --verify "$head_arg"^0) || usage
 186
 187# All the rest are remote heads
 188test "$#" = 0 && usage ;# we need at least one remote head.
 189test "$rloga" = '' && rloga="merge: $@"
 190
 191remoteheads=
 192for remote
 193do
 194        remotehead=$(git-rev-parse --verify "$remote"^0) ||
 195            die "$remote - not something we can merge"
 196        remoteheads="${remoteheads}$remotehead "
 197done
 198set x $remoteheads ; shift
 199
 200case "$use_strategies" in
 201'')
 202        case "$#" in
 203        1)
 204                use_strategies="$default_twohead_strategies" ;;
 205        *)
 206                use_strategies="$default_octopus_strategies" ;;
 207        esac
 208        ;;
 209esac
 210
 211for s in $use_strategies
 212do
 213        case " $s " in
 214        *" $no_trivial_merge_strategies "*)
 215                index_merge=f
 216                break
 217                ;;
 218        esac
 219done
 220
 221case "$#" in
 2221)
 223        common=$(git-merge-base --all $head "$@")
 224        ;;
 225*)
 226        common=$(git-show-branch --merge-base $head "$@")
 227        ;;
 228esac
 229echo "$head" >"$GIT_DIR/ORIG_HEAD"
 230
 231case "$index_merge,$#,$common,$no_commit" in
 232f,*)
 233        # We've been told not to try anything clever.  Skip to real merge.
 234        ;;
 235?,*,'',*)
 236        # No common ancestors found. We need a real merge.
 237        ;;
 238?,1,"$1",*)
 239        # If head can reach all the merge then we are up to date.
 240        # but first the most common case of merging one remote.
 241        finish_up_to_date "Already up-to-date."
 242        exit 0
 243        ;;
 244?,1,"$head",*)
 245        # Again the most common case of merging one remote.
 246        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 247        git-update-index --refresh 2>/dev/null
 248        new_head=$(git-rev-parse --verify "$1^0") &&
 249        git-read-tree -u -v -m $head "$new_head" &&
 250        finish "$new_head" "Fast forward"
 251        dropsave
 252        exit 0
 253        ;;
 254?,1,?*"$LF"?*,*)
 255        # We are not doing octopus and not fast forward.  Need a
 256        # real merge.
 257        ;;
 258?,1,*,)
 259        # We are not doing octopus, not fast forward, and have only
 260        # one common.  See if it is really trivial.
 261        git var GIT_COMMITTER_IDENT >/dev/null || exit
 262
 263        echo "Trying really trivial in-index merge..."
 264        git-update-index --refresh 2>/dev/null
 265        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 266           result_tree=$(git-write-tree)
 267        then
 268            echo "Wonderful."
 269            result_commit=$(
 270                echo "$merge_msg" |
 271                git-commit-tree $result_tree -p HEAD -p "$1"
 272            ) || exit
 273            finish "$result_commit" "In-index merge"
 274            dropsave
 275            exit 0
 276        fi
 277        echo "Nope."
 278        ;;
 279*)
 280        # An octopus.  If we can reach all the remote we are up to date.
 281        up_to_date=t
 282        for remote
 283        do
 284                common_one=$(git-merge-base --all $head $remote)
 285                if test "$common_one" != "$remote"
 286                then
 287                        up_to_date=f
 288                        break
 289                fi
 290        done
 291        if test "$up_to_date" = t
 292        then
 293                finish_up_to_date "Already up-to-date. Yeeah!"
 294                exit 0
 295        fi
 296        ;;
 297esac
 298
 299# We are going to make a new commit.
 300git var GIT_COMMITTER_IDENT >/dev/null || exit
 301
 302# At this point, we need a real merge.  No matter what strategy
 303# we use, it would operate on the index, possibly affecting the
 304# working tree, and when resolved cleanly, have the desired tree
 305# in the index -- this means that the index must be in sync with
 306# the $head commit.  The strategies are responsible to ensure this.
 307
 308case "$use_strategies" in
 309?*' '?*)
 310    # Stash away the local changes so that we can try more than one.
 311    savestate
 312    single_strategy=no
 313    ;;
 314*)
 315    rm -f "$GIT_DIR/MERGE_SAVE"
 316    single_strategy=yes
 317    ;;
 318esac
 319
 320result_tree= best_cnt=-1 best_strategy= wt_strategy=
 321merge_was_ok=
 322for strategy in $use_strategies
 323do
 324    test "$wt_strategy" = '' || {
 325        echo "Rewinding the tree to pristine..."
 326        restorestate
 327    }
 328    case "$single_strategy" in
 329    no)
 330        echo "Trying merge strategy $strategy..."
 331        ;;
 332    esac
 333
 334    # Remember which strategy left the state in the working tree
 335    wt_strategy=$strategy
 336
 337    git-merge-$strategy $common -- "$head_arg" "$@"
 338    exit=$?
 339    if test "$no_commit" = t && test "$exit" = 0
 340    then
 341        merge_was_ok=t
 342        exit=1 ;# pretend it left conflicts.
 343    fi
 344
 345    test "$exit" = 0 || {
 346
 347        # The backend exits with 1 when conflicts are left to be resolved,
 348        # with 2 when it does not handle the given merge at all.
 349
 350        if test "$exit" -eq 1
 351        then
 352            cnt=`{
 353                git-diff-files --name-only
 354                git-ls-files --unmerged
 355            } | wc -l`
 356            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 357            then
 358                best_strategy=$strategy
 359                best_cnt=$cnt
 360            fi
 361        fi
 362        continue
 363    }
 364
 365    # Automerge succeeded.
 366    result_tree=$(git-write-tree) && break
 367done
 368
 369# If we have a resulting tree, that means the strategy module
 370# auto resolved the merge cleanly.
 371if test '' != "$result_tree"
 372then
 373    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 374    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 375    finish "$result_commit" "Merge made by $wt_strategy."
 376    dropsave
 377    exit 0
 378fi
 379
 380# Pick the result from the best strategy and have the user fix it up.
 381case "$best_strategy" in
 382'')
 383        restorestate
 384        echo >&2 "No merge strategy handled the merge."
 385        exit 2
 386        ;;
 387"$wt_strategy")
 388        # We already have its result in the working tree.
 389        ;;
 390*)
 391        echo "Rewinding the tree to pristine..."
 392        restorestate
 393        echo "Using the $best_strategy to prepare resolving by hand."
 394        git-merge-$best_strategy $common -- "$head_arg" "$@"
 395        ;;
 396esac
 397
 398if test "$squash" = t
 399then
 400        finish
 401else
 402        for remote
 403        do
 404                echo $remote
 405        done >"$GIT_DIR/MERGE_HEAD"
 406        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 407fi
 408
 409if test "$merge_was_ok" = t
 410then
 411        echo >&2 \
 412        "Automatic merge went well; stopped before committing as requested"
 413        exit 0
 414else
 415        {
 416            echo '
 417Conflicts:
 418'
 419                git ls-files --unmerged |
 420                sed -e 's/^[^   ]*      /       /' |
 421                uniq
 422        } >>"$GIT_DIR/MERGE_MSG"
 423        if test -d "$GIT_DIR/rr-cache"
 424        then
 425                git-rerere
 426        fi
 427        die "Automatic merge failed; fix conflicts and then commit the result."
 428fi