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 "
 224done
 225set x $remoteheads ; shift
 226
 227case "$use_strategies" in
 228'')
 229        case "$#" in
 230        1)
 231                use_strategies="$default_twohead_strategies" ;;
 232        *)
 233                use_strategies="$default_octopus_strategies" ;;
 234        esac
 235        ;;
 236esac
 237
 238for s in $use_strategies
 239do
 240        case " $s " in
 241        *" $no_trivial_merge_strategies "*)
 242                index_merge=f
 243                break
 244                ;;
 245        esac
 246done
 247
 248case "$#" in
 2491)
 250        common=$(git-merge-base --all $head "$@")
 251        ;;
 252*)
 253        common=$(git-show-branch --merge-base $head "$@")
 254        ;;
 255esac
 256echo "$head" >"$GIT_DIR/ORIG_HEAD"
 257
 258case "$index_merge,$#,$common,$no_commit" in
 259f,*)
 260        # We've been told not to try anything clever.  Skip to real merge.
 261        ;;
 262?,*,'',*)
 263        # No common ancestors found. We need a real merge.
 264        ;;
 265?,1,"$1",*)
 266        # If head can reach all the merge then we are up to date.
 267        # but first the most common case of merging one remote.
 268        finish_up_to_date "Already up-to-date."
 269        exit 0
 270        ;;
 271?,1,"$head",*)
 272        # Again the most common case of merging one remote.
 273        echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 274        git-update-index --refresh 2>/dev/null
 275        new_head=$(git-rev-parse --verify "$1^0") &&
 276        git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 277        finish "$new_head" "Fast forward"
 278        dropsave
 279        exit 0
 280        ;;
 281?,1,?*"$LF"?*,*)
 282        # We are not doing octopus and not fast forward.  Need a
 283        # real merge.
 284        ;;
 285?,1,*,)
 286        # We are not doing octopus, not fast forward, and have only
 287        # one common.  See if it is really trivial.
 288        git var GIT_COMMITTER_IDENT >/dev/null || exit
 289
 290        echo "Trying really trivial in-index merge..."
 291        git-update-index --refresh 2>/dev/null
 292        if git-read-tree --trivial -m -u -v $common $head "$1" &&
 293           result_tree=$(git-write-tree)
 294        then
 295            echo "Wonderful."
 296            result_commit=$(
 297                echo "$merge_msg" |
 298                git-commit-tree $result_tree -p HEAD -p "$1"
 299            ) || exit
 300            finish "$result_commit" "In-index merge"
 301            dropsave
 302            exit 0
 303        fi
 304        echo "Nope."
 305        ;;
 306*)
 307        # An octopus.  If we can reach all the remote we are up to date.
 308        up_to_date=t
 309        for remote
 310        do
 311                common_one=$(git-merge-base --all $head $remote)
 312                if test "$common_one" != "$remote"
 313                then
 314                        up_to_date=f
 315                        break
 316                fi
 317        done
 318        if test "$up_to_date" = t
 319        then
 320                finish_up_to_date "Already up-to-date. Yeeah!"
 321                exit 0
 322        fi
 323        ;;
 324esac
 325
 326# We are going to make a new commit.
 327git var GIT_COMMITTER_IDENT >/dev/null || exit
 328
 329# At this point, we need a real merge.  No matter what strategy
 330# we use, it would operate on the index, possibly affecting the
 331# working tree, and when resolved cleanly, have the desired tree
 332# in the index -- this means that the index must be in sync with
 333# the $head commit.  The strategies are responsible to ensure this.
 334
 335case "$use_strategies" in
 336?*' '?*)
 337    # Stash away the local changes so that we can try more than one.
 338    savestate
 339    single_strategy=no
 340    ;;
 341*)
 342    rm -f "$GIT_DIR/MERGE_SAVE"
 343    single_strategy=yes
 344    ;;
 345esac
 346
 347result_tree= best_cnt=-1 best_strategy= wt_strategy=
 348merge_was_ok=
 349for strategy in $use_strategies
 350do
 351    test "$wt_strategy" = '' || {
 352        echo "Rewinding the tree to pristine..."
 353        restorestate
 354    }
 355    case "$single_strategy" in
 356    no)
 357        echo "Trying merge strategy $strategy..."
 358        ;;
 359    esac
 360
 361    # Remember which strategy left the state in the working tree
 362    wt_strategy=$strategy
 363
 364    git-merge-$strategy $common -- "$head_arg" "$@"
 365    exit=$?
 366    if test "$no_commit" = t && test "$exit" = 0
 367    then
 368        merge_was_ok=t
 369        exit=1 ;# pretend it left conflicts.
 370    fi
 371
 372    test "$exit" = 0 || {
 373
 374        # The backend exits with 1 when conflicts are left to be resolved,
 375        # with 2 when it does not handle the given merge at all.
 376
 377        if test "$exit" -eq 1
 378        then
 379            cnt=`{
 380                git-diff-files --name-only
 381                git-ls-files --unmerged
 382            } | wc -l`
 383            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 384            then
 385                best_strategy=$strategy
 386                best_cnt=$cnt
 387            fi
 388        fi
 389        continue
 390    }
 391
 392    # Automerge succeeded.
 393    result_tree=$(git-write-tree) && break
 394done
 395
 396# If we have a resulting tree, that means the strategy module
 397# auto resolved the merge cleanly.
 398if test '' != "$result_tree"
 399then
 400    parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
 401    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 402    finish "$result_commit" "Merge made by $wt_strategy."
 403    dropsave
 404    exit 0
 405fi
 406
 407# Pick the result from the best strategy and have the user fix it up.
 408case "$best_strategy" in
 409'')
 410        restorestate
 411        case "$use_strategies" in
 412        ?*' '?*)
 413                echo >&2 "No merge strategy handled the merge."
 414                ;;
 415        *)
 416                echo >&2 "Merge with strategy $use_strategies failed."
 417                ;;
 418        esac
 419        exit 2
 420        ;;
 421"$wt_strategy")
 422        # We already have its result in the working tree.
 423        ;;
 424*)
 425        echo "Rewinding the tree to pristine..."
 426        restorestate
 427        echo "Using the $best_strategy to prepare resolving by hand."
 428        git-merge-$best_strategy $common -- "$head_arg" "$@"
 429        ;;
 430esac
 431
 432if test "$squash" = t
 433then
 434        finish
 435else
 436        for remote
 437        do
 438                echo $remote
 439        done >"$GIT_DIR/MERGE_HEAD"
 440        echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 441fi
 442
 443if test "$merge_was_ok" = t
 444then
 445        echo >&2 \
 446        "Automatic merge went well; stopped before committing as requested"
 447        exit 0
 448else
 449        {
 450            echo '
 451Conflicts:
 452'
 453                git ls-files --unmerged |
 454                sed -e 's/^[^   ]*      /       /' |
 455                uniq
 456        } >>"$GIT_DIR/MERGE_MSG"
 457        if test -d "$GIT_DIR/rr-cache"
 458        then
 459                git-rerere
 460        fi
 461        die "Automatic merge failed; fix conflicts and then commit the result."
 462fi