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>] [--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 $head >/dev/null
  36                cpio -iuv <"$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
  94merge_name () {
  95        remote="$1"
  96        rh=$(git-rev-parse --verify "$remote^0" 2>/dev/null) || return
  97        bh=$(git-show-ref -s --verify "refs/heads/$remote" 2>/dev/null)
  98        if test "$rh" = "$bh"
  99        then
 100                echo "$rh               branch '$remote' of ."
 101        elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') &&
 102                git-show-ref -q --verify "refs/heads/$truname" 2>/dev/null
 103        then
 104                echo "$rh               branch '$truname' (early part) of ."
 105        else
 106                echo "$rh               commit '$remote'"
 107        fi
 108}
 109
 110case "$#" in 0) usage ;; esac
 111
 112rloga= have_message=
 113while case "$#" in 0) break ;; esac
 114do
 115        case "$1" in
 116        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 117                --no-summa|--no-summar|--no-summary)
 118                no_summary=t ;;
 119        --sq|--squ|--squa|--squas|--squash)
 120                squash=t no_commit=t ;;
 121        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 122                no_commit=t ;;
 123        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 124                --strateg=*|--strategy=*|\
 125        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 126                case "$#,$1" in
 127                *,*=*)
 128                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 129                1,*)
 130                        usage ;;
 131                *)
 132                        strategy="$2"
 133                        shift ;;
 134                esac
 135                case " $all_strategies " in
 136                *" $strategy "*)
 137                        use_strategies="$use_strategies$strategy " ;;
 138                *)
 139                        die "available strategies are: $all_strategies" ;;
 140                esac
 141                ;;
 142        --reflog-action=*)
 143                rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 144                ;;
 145        -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
 146                merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 147                have_message=t
 148                ;;
 149        -m|--m|--me|--mes|--mess|--messa|--messag|--message)
 150                shift
 151                case "$#" in
 152                1)      usage ;;
 153                esac
 154                merge_msg="$1"
 155                have_message=t
 156                ;;
 157        -*)     usage ;;
 158        *)      break ;;
 159        esac
 160        shift
 161done
 162
 163# This could be traditional "merge <msg> HEAD <commit>..."  and the
 164# way we can tell it is to see if the second token is HEAD, but some
 165# people might have misused the interface and used a committish that
 166# is the same as HEAD there instead.  Traditional format never would
 167# have "-m" so it is an additional safety measure to check for it.
 168
 169if test -z "$have_message" &&
 170        second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
 171        head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
 172        test "$second_token" = "$head_commit"
 173then
 174        merge_msg="$1"
 175        shift
 176        head_arg="$1"
 177        shift
 178elif ! git-rev-parse --verify HEAD >/dev/null 2>&1
 179then
 180        # If the merged head is a valid one there is no reason to
 181        # forbid "git merge" into a branch yet to be born.  We do
 182        # the same for "git pull".
 183        if test 1 -ne $#
 184        then
 185                echo >&2 "Can merge only exactly one commit into empty head"
 186                exit 1
 187        fi
 188
 189        rh=$(git rev-parse --verify "$1^0") ||
 190                die "$1 - not something we can merge"
 191
 192        git-update-ref -m "initial pull" HEAD "$rh" "" &&
 193        git-read-tree --reset -u HEAD
 194        exit
 195
 196else
 197        # We are invoked directly as the first-class UI.
 198        head_arg=HEAD
 199
 200        # All the rest are the commits being merged; prepare
 201        # the standard merge summary message to be appended to
 202        # the given message.  If remote is invalid we will die
 203        # later in the common codepath so we discard the error
 204        # in this loop.
 205        merge_name=$(for remote
 206                do
 207                        merge_name "$remote"
 208                done | git-fmt-merge-msg
 209        )
 210        merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 211fi
 212head=$(git-rev-parse --verify "$head_arg"^0) || usage
 213
 214# All the rest are remote heads
 215test "$#" = 0 && usage ;# we need at least one remote head.
 216test "$rloga" = '' && rloga="merge: $@"
 217
 218remoteheads=
 219for remote
 220do
 221        remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) ||
 222            die "$remote - not something we can merge"
 223        remoteheads="${remoteheads}$remotehead "
 224        eval GITHEAD_$remotehead='"$remote"'
 225        export GITHEAD_$remotehead
 226done
 227set x $remoteheads ; shift
 228
 229case "$use_strategies" in
 230'')
 231        case "$#" in
 232        1)
 233                use_strategies="$default_twohead_strategies" ;;
 234        *)
 235                use_strategies="$default_octopus_strategies" ;;
 236        esac
 237        ;;
 238esac
 239
 240for s in $use_strategies
 241do
 242        case " $s " in
 243        *" $no_trivial_merge_strategies "*)
 244                index_merge=f
 245                break
 246                ;;
 247        esac
 248done
 249
 250case "$#" in
 2511)
 252        common=$(git-merge-base --all $head "$@")
 253        ;;
 254*)
 255        common=$(git-show-branch --merge-base $head "$@")
 256        ;;
 257esac
 258echo "$head" >"$GIT_DIR/ORIG_HEAD"
 259
 260case "$index_merge,$#,$common,$no_commit" in
 261f,*)
 262        # We've been told not to try anything clever.  Skip to real merge.
 263        ;;
 264?,*,'',*)
 265        # No common ancestors found. We need a real merge.
 266        ;;
 267?,1,"$1",*)
 268        # If head can reach all the merge then we are up to date.
 269        # but first the most common case of merging one remote.
 270        finish_up_to_date "Already up-to-date."
 271        exit 0
 272        ;;
 273?,1,"$head",*)
 274        # Again the most common case of merging one remote.
 275        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 276        git-update-index --refresh 2>/dev/null
 277        new_head=$(git-rev-parse --verify "$1^0") &&
 278        git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 279        finish "$new_head" "Fast forward"
 280        dropsave
 281        exit 0
 282        ;;
 283?,1,?*"$LF"?*,*)
 284        # We are not doing octopus and not fast forward.  Need a
 285        # real merge.
 286        ;;
 287?,1,*,)
 288        # We are not doing octopus, not fast forward, and have only
 289        # one common.  See if it is really trivial.
 290        git var GIT_COMMITTER_IDENT >/dev/null || exit
 291
 292        echo "Trying really trivial in-index merge..."
 293        git-update-index --refresh 2>/dev/null
 294        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 295           result_tree=$(git-write-tree)
 296        then
 297            echo "Wonderful."
 298            result_commit=$(
 299                echo "$merge_msg" |
 300                git-commit-tree $result_tree -p HEAD -p "$1"
 301            ) || exit
 302            finish "$result_commit" "In-index merge"
 303            dropsave
 304            exit 0
 305        fi
 306        echo "Nope."
 307        ;;
 308*)
 309        # An octopus.  If we can reach all the remote we are up to date.
 310        up_to_date=t
 311        for remote
 312        do
 313                common_one=$(git-merge-base --all $head $remote)
 314                if test "$common_one" != "$remote"
 315                then
 316                        up_to_date=f
 317                        break
 318                fi
 319        done
 320        if test "$up_to_date" = t
 321        then
 322                finish_up_to_date "Already up-to-date. Yeeah!"
 323                exit 0
 324        fi
 325        ;;
 326esac
 327
 328# We are going to make a new commit.
 329git var GIT_COMMITTER_IDENT >/dev/null || exit
 330
 331# At this point, we need a real merge.  No matter what strategy
 332# we use, it would operate on the index, possibly affecting the
 333# working tree, and when resolved cleanly, have the desired tree
 334# in the index -- this means that the index must be in sync with
 335# the $head commit.  The strategies are responsible to ensure this.
 336
 337case "$use_strategies" in
 338?*' '?*)
 339    # Stash away the local changes so that we can try more than one.
 340    savestate
 341    single_strategy=no
 342    ;;
 343*)
 344    rm -f "$GIT_DIR/MERGE_SAVE"
 345    single_strategy=yes
 346    ;;
 347esac
 348
 349result_tree= best_cnt=-1 best_strategy= wt_strategy=
 350merge_was_ok=
 351for strategy in $use_strategies
 352do
 353    test "$wt_strategy" = '' || {
 354        echo "Rewinding the tree to pristine..."
 355        restorestate
 356    }
 357    case "$single_strategy" in
 358    no)
 359        echo "Trying merge strategy $strategy..."
 360        ;;
 361    esac
 362
 363    # Remember which strategy left the state in the working tree
 364    wt_strategy=$strategy
 365
 366    git-merge-$strategy $common -- "$head_arg" "$@"
 367    exit=$?
 368    if test "$no_commit" = t && test "$exit" = 0
 369    then
 370        merge_was_ok=t
 371        exit=1 ;# pretend it left conflicts.
 372    fi
 373
 374    test "$exit" = 0 || {
 375
 376        # The backend exits with 1 when conflicts are left to be resolved,
 377        # with 2 when it does not handle the given merge at all.
 378
 379        if test "$exit" -eq 1
 380        then
 381            cnt=`{
 382                git-diff-files --name-only
 383                git-ls-files --unmerged
 384            } | wc -l`
 385            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 386            then
 387                best_strategy=$strategy
 388                best_cnt=$cnt
 389            fi
 390        fi
 391        continue
 392    }
 393
 394    # Automerge succeeded.
 395    result_tree=$(git-write-tree) && break
 396done
 397
 398# If we have a resulting tree, that means the strategy module
 399# auto resolved the merge cleanly.
 400if test '' != "$result_tree"
 401then
 402    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 403    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 404    finish "$result_commit" "Merge made by $wt_strategy."
 405    dropsave
 406    exit 0
 407fi
 408
 409# Pick the result from the best strategy and have the user fix it up.
 410case "$best_strategy" in
 411'')
 412        restorestate
 413        case "$use_strategies" in
 414        ?*' '?*)
 415                echo >&2 "No merge strategy handled the merge."
 416                ;;
 417        *)
 418                echo >&2 "Merge with strategy $use_strategies failed."
 419                ;;
 420        esac
 421        exit 2
 422        ;;
 423"$wt_strategy")
 424        # We already have its result in the working tree.
 425        ;;
 426*)
 427        echo "Rewinding the tree to pristine..."
 428        restorestate
 429        echo "Using the $best_strategy to prepare resolving by hand."
 430        git-merge-$best_strategy $common -- "$head_arg" "$@"
 431        ;;
 432esac
 433
 434if test "$squash" = t
 435then
 436        finish
 437else
 438        for remote
 439        do
 440                echo $remote
 441        done >"$GIT_DIR/MERGE_HEAD"
 442        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 443fi
 444
 445if test "$merge_was_ok" = t
 446then
 447        echo >&2 \
 448        "Automatic merge went well; stopped before committing as requested"
 449        exit 0
 450else
 451        {
 452            echo '
 453Conflicts:
 454'
 455                git ls-files --unmerged |
 456                sed -e 's/^[^   ]*      /       /' |
 457                uniq
 458        } >>"$GIT_DIR/MERGE_MSG"
 459        if test -d "$GIT_DIR/rr-cache"
 460        then
 461                git-rerere
 462        fi
 463        die "Automatic merge failed; fix conflicts and then commit the result."
 464fi