Andrew's git - gitweb.git/blob

d25ae4b82d4208216bb7ce5b5d414ee8b2797865
   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6. git-sh-setup
   7
   8LF='
   9'
  10
  11usage () {
  12    die "git-merge [-n] [--no-commit] [-s <strategy>]... <merge-message> <head> <remote>+"
  13}
  14
  15all_strategies='recursive octopus resolve stupid ours'
  16default_strategies='recursive'
  17use_strategies=
  18
  19dropsave() {
  20        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  21                 "$GIT_DIR/MERGE_SAVE" || exit 1
  22}
  23
  24savestate() {
  25        # Stash away any local modifications.
  26        git-diff-index -z --name-only $head |
  27        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  28}
  29
  30restorestate() {
  31        if test -f "$GIT_DIR/MERGE_SAVE"
  32        then
  33                git reset --hard $head
  34                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  35                git-update-index --refresh >/dev/null
  36        fi
  37}
  38
  39finish () {
  40        test '' = "$2" || echo "$2"
  41        case "$merge_msg" in
  42        '')
  43                echo "No merge message -- not updating HEAD"
  44                ;;
  45        *)
  46                git-update-ref HEAD "$1" "$head" || exit 1
  47                ;;
  48        esac
  49
  50        case "$no_summary" in
  51        '')
  52                git-diff-tree -p -M "$head" "$1" |
  53                git-apply --stat --summary
  54                ;;
  55        esac
  56}
  57
  58while case "$#" in 0) break ;; esac
  59do
  60        case "$1" in
  61        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
  62                --no-summa|--no-summar|--no-summary)
  63                no_summary=t ;;
  64        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
  65                no_commit=t ;;
  66        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
  67                --strateg=*|--strategy=*|\
  68        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
  69                case "$#,$1" in
  70                *,*=*)
  71                        strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
  72                1,*)
  73                        usage ;;
  74                *)
  75                        strategy="$2"
  76                        shift ;;
  77                esac
  78                case " $all_strategies " in
  79                *" $strategy "*)
  80                        use_strategies="$use_strategies$strategy " ;;
  81                *)
  82                        die "available strategies are: $all_strategies" ;;
  83                esac
  84                ;;
  85        -*)     usage ;;
  86        *)      break ;;
  87        esac
  88        shift
  89done
  90
  91test "$#" -le 2 && usage ;# we need at least two heads.
  92
  93merge_msg="$1"
  94shift
  95head_arg="$1"
  96head=$(git-rev-parse --verify "$1"^0) || usage
  97shift
  98
  99# All the rest are remote heads
 100remoteheads=
 101for remote
 102do
 103        remotehead=$(git-rev-parse --verify "$remote"^0) ||
 104            die "$remote - not something we can merge"
 105        remoteheads="${remoteheads}$remotehead "
 106done
 107set x $remoteheads ; shift
 108
 109case "$#" in
 1101)
 111        common=$(git-merge-base --all $head "$@")
 112        ;;
 113*)
 114        common=$(git-show-branch --merge-base $head "$@")
 115        ;;
 116esac
 117echo "$head" >"$GIT_DIR/ORIG_HEAD"
 118
 119case "$#,$common,$no_commit" in
 120*,'',*)
 121        # No common ancestors found. We need a real merge.
 122        ;;
 1231,"$1",*)
 124        # If head can reach all the merge then we are up to date.
 125        # but first the most common case of merging one remote
 126        echo "Already up-to-date."
 127        dropsave
 128        exit 0
 129        ;;
 1301,"$head",*)
 131        # Again the most common case of merging one remote.
 132        echo "Updating from $head to $1."
 133        git-update-index --refresh 2>/dev/null
 134        new_head=$(git-rev-parse --verify "$1^0") &&
 135        git-read-tree -u -m $head "$new_head" &&
 136        finish "$new_head" "Fast forward"
 137        dropsave
 138        exit 0
 139        ;;
 1401,?*"$LF"?*,*)
 141        # We are not doing octopus and not fast forward.  Need a
 142        # real merge.
 143        ;;
 1441,*,)
 145        # We are not doing octopus, not fast forward, and have only
 146        # one common.  See if it is really trivial.
 147        echo "Trying really trivial in-index merge..."
 148        git-update-index --refresh 2>/dev/null
 149        if git-read-tree --trivial -m -u $common $head "$1" &&
 150           result_tree=$(git-write-tree)
 151        then
 152            echo "Wonderful."
 153            result_commit=$(
 154                echo "$merge_msg" |
 155                git-commit-tree $result_tree -p HEAD -p "$1"
 156            ) || exit
 157            finish "$result_commit" "In-index merge"
 158            dropsave
 159            exit 0
 160        fi
 161        echo "Nope."
 162        ;;
 163*)
 164        # An octopus.  If we can reach all the remote we are up to date.
 165        up_to_date=t
 166        for remote
 167        do
 168                common_one=$(git-merge-base --all $head $remote)
 169                if test "$common_one" != "$remote"
 170                then
 171                        up_to_date=f
 172                        break
 173                fi
 174        done
 175        if test "$up_to_date" = t
 176        then
 177                echo "Already up-to-date. Yeeah!"
 178                dropsave
 179                exit 0
 180        fi
 181        ;;
 182esac
 183
 184case "$use_strategies" in
 185'')
 186        case "$#" in
 187        1)
 188                use_strategies="$default_strategies" ;;
 189        *)
 190                use_strategies=octopus ;;
 191        esac            
 192        ;;
 193esac
 194
 195# At this point, we need a real merge.  No matter what strategy
 196# we use, it would operate on the index, possibly affecting the
 197# working tree, and when resolved cleanly, have the desired tree
 198# in the index -- this means that the index must be in sync with
 199# the $head commit.  The strategies are responsible to ensure this.
 200
 201case "$use_strategies" in
 202?*' '?*)
 203    # Stash away the local changes so that we can try more than one.
 204    savestate
 205    single_strategy=no
 206    ;;
 207*)
 208    rm -f "$GIT_DIR/MERGE_SAVE"
 209    single_strategy=yes
 210    ;;
 211esac
 212
 213result_tree= best_cnt=-1 best_strategy= wt_strategy=
 214for strategy in $use_strategies
 215do
 216    test "$wt_strategy" = '' || {
 217        echo "Rewinding the tree to pristine..."
 218        restorestate
 219    }
 220    case "$single_strategy" in
 221    no)
 222        echo "Trying merge strategy $strategy..."
 223        ;;
 224    esac
 225
 226    # Remember which strategy left the state in the working tree
 227    wt_strategy=$strategy
 228
 229    git-merge-$strategy $common -- "$head_arg" "$@"
 230    exit=$?
 231    if test "$no_commit" = t && test "$exit" = 0
 232    then
 233        exit=1 ;# pretend it left conflicts.
 234    fi
 235
 236    test "$exit" = 0 || {
 237
 238        # The backend exits with 1 when conflicts are left to be resolved,
 239        # with 2 when it does not handle the given merge at all.
 240
 241        if test "$exit" -eq 1
 242        then
 243            cnt=`{
 244                git-diff-files --name-only
 245                git-ls-files --unmerged
 246            } | wc -l`
 247            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 248            then
 249                best_strategy=$strategy
 250                best_cnt=$cnt
 251            fi
 252        fi
 253        continue
 254    }
 255
 256    # Automerge succeeded.
 257    result_tree=$(git-write-tree) && break
 258done
 259
 260# If we have a resulting tree, that means the strategy module
 261# auto resolved the merge cleanly.
 262if test '' != "$result_tree"
 263then
 264    parents="-p $head"
 265    for remote
 266    do
 267        parents="$parents -p $remote"
 268    done
 269    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 270    finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
 271    dropsave
 272    exit 0
 273fi
 274
 275# Pick the result from the best strategy and have the user fix it up.
 276case "$best_strategy" in
 277'')
 278        restorestate
 279        echo >&2 "No merge strategy handled the merge."
 280        exit 2
 281        ;;
 282"$wt_strategy")
 283        # We already have its result in the working tree.
 284        ;;
 285*)
 286        echo "Rewinding the tree to pristine..."
 287        restorestate
 288        echo "Using the $best_strategy to prepare resolving by hand."
 289        git-merge-$best_strategy $common -- "$head_arg" "$@"
 290        ;;
 291esac
 292for remote
 293do
 294        echo $remote
 295done >"$GIT_DIR/MERGE_HEAD"
 296echo $merge_msg >"$GIT_DIR/MERGE_MSG"
 297
 298die "Automatic merge failed/prevented; fix up by hand"