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
  10set_reflog_action "merge $*"
  11require_work_tree
  12cd_to_toplevel
  13
  14test -z "$(git ls-files -u)" ||
  15        die "You are in the middle of a conflicted merge."
  16
  17LF='
  18'
  19
  20all_strategies='recur recursive octopus resolve stupid ours'
  21default_twohead_strategies='recursive'
  22default_octopus_strategies='octopus'
  23no_trivial_merge_strategies='ours'
  24use_strategies=
  25
  26index_merge=t
  27
  28dropsave() {
  29        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  30                 "$GIT_DIR/MERGE_SAVE" || exit 1
  31}
  32
  33savestate() {
  34        # Stash away any local modifications.
  35        git-diff-index -z --name-only $head |
  36        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  37}
  38
  39restorestate() {
  40        if test -f "$GIT_DIR/MERGE_SAVE"
  41        then
  42                git reset --hard $head >/dev/null
  43                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  44                git-update-index --refresh >/dev/null
  45        fi
  46}
  47
  48finish_up_to_date () {
  49        case "$squash" in
  50        t)
  51                echo "$1 (nothing to squash)" ;;
  52        '')
  53                echo "$1" ;;
  54        esac
  55        dropsave
  56}
  57
  58squash_message () {
  59        echo Squashed commit of the following:
  60        echo
  61        git-log --no-merges ^"$head" $remote
  62}
  63
  64finish () {
  65        if test '' = "$2"
  66        then
  67                rlogm="$GIT_REFLOG_ACTION"
  68        else
  69                echo "$2"
  70                rlogm="$GIT_REFLOG_ACTION: $2"
  71        fi
  72        case "$squash" in
  73        t)
  74                echo "Squash commit -- not updating HEAD"
  75                squash_message >"$GIT_DIR/SQUASH_MSG"
  76                ;;
  77        '')
  78                case "$merge_msg" in
  79                '')
  80                        echo "No merge message -- not updating HEAD"
  81                        ;;
  82                *)
  83                        git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
  84                        ;;
  85                esac
  86                ;;
  87        esac
  88        case "$1" in
  89        '')
  90                ;;
  91        ?*)
  92                case "$no_summary" in
  93                '')
  94                        git-diff-tree --stat --summary -M "$head" "$1"
  95                        ;;
  96                esac
  97                ;;
  98        esac
  99}
 100
 101merge_name () {
 102        remote="$1"
 103        rh=$(git-rev-parse --verify "$remote^0" 2>/dev/null) || return
 104        bh=$(git-show-ref -s --verify "refs/heads/$remote" 2>/dev/null)
 105        if test "$rh" = "$bh"
 106        then
 107                echo "$rh               branch '$remote' of ."
 108        elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') &&
 109                git-show-ref -q --verify "refs/heads/$truname" 2>/dev/null
 110        then
 111                echo "$rh               branch '$truname' (early part) of ."
 112        else
 113                echo "$rh               commit '$remote'"
 114        fi
 115}
 116
 117case "$#" in 0) usage ;; esac
 118
 119have_message=
 120while case "$#" in 0) break ;; esac
 121do
 122        case "$1" in
 123        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
 124                --no-summa|--no-summar|--no-summary)
 125                no_summary=t ;;
 126        --sq|--squ|--squa|--squas|--squash)
 127                squash=t no_commit=t ;;
 128        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 129                no_commit=t ;;
 130        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
 131                --strateg=*|--strategy=*|\
 132        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
 133                case "$#,$1" in
 134                *,*=*)
 135                        strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
 136                1,*)
 137                        usage ;;
 138                *)
 139                        strategy="$2"
 140                        shift ;;
 141                esac
 142                case " $all_strategies " in
 143                *" $strategy "*)
 144                        use_strategies="$use_strategies$strategy " ;;
 145                *)
 146                        die "available strategies are: $all_strategies" ;;
 147                esac
 148                ;;
 149        -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
 150                merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
 151                have_message=t
 152                ;;
 153        -m|--m|--me|--mes|--mess|--messa|--messag|--message)
 154                shift
 155                case "$#" in
 156                1)      usage ;;
 157                esac
 158                merge_msg="$1"
 159                have_message=t
 160                ;;
 161        -*)     usage ;;
 162        *)      break ;;
 163        esac
 164        shift
 165done
 166
 167# This could be traditional "merge <msg> HEAD <commit>..."  and the
 168# way we can tell it is to see if the second token is HEAD, but some
 169# people might have misused the interface and used a committish that
 170# is the same as HEAD there instead.  Traditional format never would
 171# have "-m" so it is an additional safety measure to check for it.
 172
 173if test -z "$have_message" &&
 174        second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
 175        head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
 176        test "$second_token" = "$head_commit"
 177then
 178        merge_msg="$1"
 179        shift
 180        head_arg="$1"
 181        shift
 182elif ! git-rev-parse --verify HEAD >/dev/null 2>&1
 183then
 184        # If the merged head is a valid one there is no reason to
 185        # forbid "git merge" into a branch yet to be born.  We do
 186        # the same for "git pull".
 187        if test 1 -ne $#
 188        then
 189                echo >&2 "Can merge only exactly one commit into empty head"
 190                exit 1
 191        fi
 192
 193        rh=$(git rev-parse --verify "$1^0") ||
 194                die "$1 - not something we can merge"
 195
 196        git-update-ref -m "initial pull" HEAD "$rh" "" &&
 197        git-read-tree --reset -u HEAD
 198        exit
 199
 200else
 201        # We are invoked directly as the first-class UI.
 202        head_arg=HEAD
 203
 204        # All the rest are the commits being merged; prepare
 205        # the standard merge summary message to be appended to
 206        # the given message.  If remote is invalid we will die
 207        # later in the common codepath so we discard the error
 208        # in this loop.
 209        merge_name=$(for remote
 210                do
 211                        merge_name "$remote"
 212                done | git-fmt-merge-msg
 213        )
 214        merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
 215fi
 216head=$(git-rev-parse --verify "$head_arg"^0) || usage
 217
 218# All the rest are remote heads
 219test "$#" = 0 && usage ;# we need at least one remote head.
 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 "$#" in
 235        1)
 236                var="`git-repo-config --get pull.twohead`"
 237                if test -n "$var"
 238                then
 239                        use_strategies="$var"
 240                else
 241                        use_strategies="$default_twohead_strategies"
 242                fi ;;
 243        *)
 244                var="`git-repo-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        case " $s " in
 258        *" $no_trivial_merge_strategies "*)
 259                index_merge=f
 260                break
 261                ;;
 262        esac
 263done
 264
 265case "$#" in
 2661)
 267        common=$(git-merge-base --all $head "$@")
 268        ;;
 269*)
 270        common=$(git-show-branch --merge-base $head "$@")
 271        ;;
 272esac
 273echo "$head" >"$GIT_DIR/ORIG_HEAD"
 274
 275case "$index_merge,$#,$common,$no_commit" in
 276f,*)
 277        # We've been told not to try anything clever.  Skip to real merge.
 278        ;;
 279?,*,'',*)
 280        # No common ancestors found. We need a real merge.
 281        ;;
 282?,1,"$1",*)
 283        # If head can reach all the merge then we are up to date.
 284        # but first the most common case of merging one remote.
 285        finish_up_to_date "Already up-to-date."
 286        exit 0
 287        ;;
 288?,1,"$head",*)
 289        # Again the most common case of merging one remote.
 290        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 291        git-update-index --refresh 2>/dev/null
 292        new_head=$(git-rev-parse --verify "$1^0") &&
 293        git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 294        finish "$new_head" "Fast forward"
 295        dropsave
 296        exit 0
 297        ;;
 298?,1,?*"$LF"?*,*)
 299        # We are not doing octopus and not fast forward.  Need a
 300        # real merge.
 301        ;;
 302?,1,*,)
 303        # We are not doing octopus, not fast forward, and have only
 304        # one common.  See if it is really trivial.
 305        git var GIT_COMMITTER_IDENT >/dev/null || exit
 306
 307        echo "Trying really trivial in-index merge..."
 308        git-update-index --refresh 2>/dev/null
 309        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 310           result_tree=$(git-write-tree)
 311        then
 312            echo "Wonderful."
 313            result_commit=$(
 314                echo "$merge_msg" |
 315                git-commit-tree $result_tree -p HEAD -p "$1"
 316            ) || exit
 317            finish "$result_commit" "In-index merge"
 318            dropsave
 319            exit 0
 320        fi
 321        echo "Nope."
 322        ;;
 323*)
 324        # An octopus.  If we can reach all the remote we are up to date.
 325        up_to_date=t
 326        for remote
 327        do
 328                common_one=$(git-merge-base --all $head $remote)
 329                if test "$common_one" != "$remote"
 330                then
 331                        up_to_date=f
 332                        break
 333                fi
 334        done
 335        if test "$up_to_date" = t
 336        then
 337                finish_up_to_date "Already up-to-date. Yeeah!"
 338                exit 0
 339        fi
 340        ;;
 341esac
 342
 343# We are going to make a new commit.
 344git var GIT_COMMITTER_IDENT >/dev/null || exit
 345
 346# At this point, we need a real merge.  No matter what strategy
 347# we use, it would operate on the index, possibly affecting the
 348# working tree, and when resolved cleanly, have the desired tree
 349# in the index -- this means that the index must be in sync with
 350# the $head commit.  The strategies are responsible to ensure this.
 351
 352case "$use_strategies" in
 353?*' '?*)
 354    # Stash away the local changes so that we can try more than one.
 355    savestate
 356    single_strategy=no
 357    ;;
 358*)
 359    rm -f "$GIT_DIR/MERGE_SAVE"
 360    single_strategy=yes
 361    ;;
 362esac
 363
 364result_tree= best_cnt=-1 best_strategy= wt_strategy=
 365merge_was_ok=
 366for strategy in $use_strategies
 367do
 368    test "$wt_strategy" = '' || {
 369        echo "Rewinding the tree to pristine..."
 370        restorestate
 371    }
 372    case "$single_strategy" in
 373    no)
 374        echo "Trying merge strategy $strategy..."
 375        ;;
 376    esac
 377
 378    # Remember which strategy left the state in the working tree
 379    wt_strategy=$strategy
 380
 381    git-merge-$strategy $common -- "$head_arg" "$@"
 382    exit=$?
 383    if test "$no_commit" = t && test "$exit" = 0
 384    then
 385        merge_was_ok=t
 386        exit=1 ;# pretend it left conflicts.
 387    fi
 388
 389    test "$exit" = 0 || {
 390
 391        # The backend exits with 1 when conflicts are left to be resolved,
 392        # with 2 when it does not handle the given merge at all.
 393
 394        if test "$exit" -eq 1
 395        then
 396            cnt=`{
 397                git-diff-files --name-only
 398                git-ls-files --unmerged
 399            } | wc -l`
 400            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 401            then
 402                best_strategy=$strategy
 403                best_cnt=$cnt
 404            fi
 405        fi
 406        continue
 407    }
 408
 409    # Automerge succeeded.
 410    result_tree=$(git-write-tree) && break
 411done
 412
 413# If we have a resulting tree, that means the strategy module
 414# auto resolved the merge cleanly.
 415if test '' != "$result_tree"
 416then
 417    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 418    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 419    finish "$result_commit" "Merge made by $wt_strategy."
 420    dropsave
 421    exit 0
 422fi
 423
 424# Pick the result from the best strategy and have the user fix it up.
 425case "$best_strategy" in
 426'')
 427        restorestate
 428        case "$use_strategies" in
 429        ?*' '?*)
 430                echo >&2 "No merge strategy handled the merge."
 431                ;;
 432        *)
 433                echo >&2 "Merge with strategy $use_strategies failed."
 434                ;;
 435        esac
 436        exit 2
 437        ;;
 438"$wt_strategy")
 439        # We already have its result in the working tree.
 440        ;;
 441*)
 442        echo "Rewinding the tree to pristine..."
 443        restorestate
 444        echo "Using the $best_strategy to prepare resolving by hand."
 445        git-merge-$best_strategy $common -- "$head_arg" "$@"
 446        ;;
 447esac
 448
 449if test "$squash" = t
 450then
 451        finish
 452else
 453        for remote
 454        do
 455                echo $remote
 456        done >"$GIT_DIR/MERGE_HEAD"
 457        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 458fi
 459
 460if test "$merge_was_ok" = t
 461then
 462        echo >&2 \
 463        "Automatic merge went well; stopped before committing as requested"
 464        exit 0
 465else
 466        {
 467            echo '
 468Conflicts:
 469'
 470                git ls-files --unmerged |
 471                sed -e 's/^[^   ]*      /       /' |
 472                uniq
 473        } >>"$GIT_DIR/MERGE_MSG"
 474        if test -d "$GIT_DIR/rr-cache"
 475        then
 476                git-rerere
 477        fi
 478        die "Automatic merge failed; fix conflicts and then commit the result."
 479fi