Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6
   7USAGE='[-n] [--no-commit] [-s <strategy>]... <merge-message> <head> <remote>+'
   8. git-sh-setup
   9
  10LF='
  11'
  12
  13all_strategies='recursive octopus resolve stupid ours'
  14default_strategies='recursive'
  15use_strategies=
  16
  17dropsave() {
  18        rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
  19                 "$GIT_DIR/MERGE_SAVE" || exit 1
  20}
  21
  22savestate() {
  23        # Stash away any local modifications.
  24        git-diff-index -z --name-only $head |
  25        cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
  26}
  27
  28restorestate() {
  29        if test -f "$GIT_DIR/MERGE_SAVE"
  30        then
  31                git reset --hard $head
  32                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  33                git-update-index --refresh >/dev/null
  34        fi
  35}
  36
  37finish () {
  38        test '' = "$2" || echo "$2"
  39        case "$merge_msg" in
  40        '')
  41                echo "No merge message -- not updating HEAD"
  42                ;;
  43        *)
  44                git-update-ref HEAD "$1" "$head" || exit 1
  45                ;;
  46        esac
  47
  48        case "$no_summary" in
  49        '')
  50                git-diff-tree -p -M "$head" "$1" |
  51                git-apply --stat --summary
  52                ;;
  53        esac
  54}
  55
  56while case "$#" in 0) break ;; esac
  57do
  58        case "$1" in
  59        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
  60                --no-summa|--no-summar|--no-summary)
  61                no_summary=t ;;
  62        --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
  63                no_commit=t ;;
  64        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
  65                --strateg=*|--strategy=*|\
  66        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
  67                case "$#,$1" in
  68                *,*=*)
  69                        strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
  70                1,*)
  71                        usage ;;
  72                *)
  73                        strategy="$2"
  74                        shift ;;
  75                esac
  76                case " $all_strategies " in
  77                *" $strategy "*)
  78                        use_strategies="$use_strategies$strategy " ;;
  79                *)
  80                        die "available strategies are: $all_strategies" ;;
  81                esac
  82                ;;
  83        -*)     usage ;;
  84        *)      break ;;
  85        esac
  86        shift
  87done
  88
  89test "$#" -le 2 && usage ;# we need at least two heads.
  90
  91merge_msg="$1"
  92shift
  93head_arg="$1"
  94head=$(git-rev-parse --verify "$1"^0) || usage
  95shift
  96
  97# All the rest are remote heads
  98remoteheads=
  99for remote
 100do
 101        remotehead=$(git-rev-parse --verify "$remote"^0) ||
 102            die "$remote - not something we can merge"
 103        remoteheads="${remoteheads}$remotehead "
 104done
 105set x $remoteheads ; shift
 106
 107case "$#" in
 1081)
 109        common=$(git-merge-base --all $head "$@")
 110        ;;
 111*)
 112        common=$(git-show-branch --merge-base $head "$@")
 113        ;;
 114esac
 115echo "$head" >"$GIT_DIR/ORIG_HEAD"
 116
 117case "$#,$common,$no_commit" in
 118*,'',*)
 119        # No common ancestors found. We need a real merge.
 120        ;;
 1211,"$1",*)
 122        # If head can reach all the merge then we are up to date.
 123        # but first the most common case of merging one remote
 124        echo "Already up-to-date."
 125        dropsave
 126        exit 0
 127        ;;
 1281,"$head",*)
 129        # Again the most common case of merging one remote.
 130        echo "Updating from $head to $1."
 131        git-update-index --refresh 2>/dev/null
 132        new_head=$(git-rev-parse --verify "$1^0") &&
 133        git-read-tree -u -m $head "$new_head" &&
 134        finish "$new_head" "Fast forward"
 135        dropsave
 136        exit 0
 137        ;;
 1381,?*"$LF"?*,*)
 139        # We are not doing octopus and not fast forward.  Need a
 140        # real merge.
 141        ;;
 1421,*,)
 143        # We are not doing octopus, not fast forward, and have only
 144        # one common.  See if it is really trivial.
 145        git var GIT_COMMITTER_IDENT >/dev/null || exit
 146
 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
 184# We are going to make a new commit.
 185git var GIT_COMMITTER_IDENT >/dev/null || exit
 186
 187case "$use_strategies" in
 188'')
 189        case "$#" in
 190        1)
 191                use_strategies="$default_strategies" ;;
 192        *)
 193                use_strategies=octopus ;;
 194        esac            
 195        ;;
 196esac
 197
 198# At this point, we need a real merge.  No matter what strategy
 199# we use, it would operate on the index, possibly affecting the
 200# working tree, and when resolved cleanly, have the desired tree
 201# in the index -- this means that the index must be in sync with
 202# the $head commit.  The strategies are responsible to ensure this.
 203
 204case "$use_strategies" in
 205?*' '?*)
 206    # Stash away the local changes so that we can try more than one.
 207    savestate
 208    single_strategy=no
 209    ;;
 210*)
 211    rm -f "$GIT_DIR/MERGE_SAVE"
 212    single_strategy=yes
 213    ;;
 214esac
 215
 216result_tree= best_cnt=-1 best_strategy= wt_strategy=
 217merge_was_ok=
 218for strategy in $use_strategies
 219do
 220    test "$wt_strategy" = '' || {
 221        echo "Rewinding the tree to pristine..."
 222        restorestate
 223    }
 224    case "$single_strategy" in
 225    no)
 226        echo "Trying merge strategy $strategy..."
 227        ;;
 228    esac
 229
 230    # Remember which strategy left the state in the working tree
 231    wt_strategy=$strategy
 232
 233    git-merge-$strategy $common -- "$head_arg" "$@"
 234    exit=$?
 235    if test "$no_commit" = t && test "$exit" = 0
 236    then
 237        merge_was_ok=t
 238        exit=1 ;# pretend it left conflicts.
 239    fi
 240
 241    test "$exit" = 0 || {
 242
 243        # The backend exits with 1 when conflicts are left to be resolved,
 244        # with 2 when it does not handle the given merge at all.
 245
 246        if test "$exit" -eq 1
 247        then
 248            cnt=`{
 249                git-diff-files --name-only
 250                git-ls-files --unmerged
 251            } | wc -l`
 252            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 253            then
 254                best_strategy=$strategy
 255                best_cnt=$cnt
 256            fi
 257        fi
 258        continue
 259    }
 260
 261    # Automerge succeeded.
 262    result_tree=$(git-write-tree) && break
 263done
 264
 265# If we have a resulting tree, that means the strategy module
 266# auto resolved the merge cleanly.
 267if test '' != "$result_tree"
 268then
 269    parents="-p $head"
 270    for remote
 271    do
 272        parents="$parents -p $remote"
 273    done
 274    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 275    finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
 276    dropsave
 277    exit 0
 278fi
 279
 280# Pick the result from the best strategy and have the user fix it up.
 281case "$best_strategy" in
 282'')
 283        restorestate
 284        echo >&2 "No merge strategy handled the merge."
 285        exit 2
 286        ;;
 287"$wt_strategy")
 288        # We already have its result in the working tree.
 289        ;;
 290*)
 291        echo "Rewinding the tree to pristine..."
 292        restorestate
 293        echo "Using the $best_strategy to prepare resolving by hand."
 294        git-merge-$best_strategy $common -- "$head_arg" "$@"
 295        ;;
 296esac
 297for remote
 298do
 299        echo $remote
 300done >"$GIT_DIR/MERGE_HEAD"
 301echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
 302
 303if test "$merge_was_ok" = t
 304then
 305        echo >&2 \
 306        "Automatic merge went well; stopped before committing as requested"
 307        exit 0
 308else
 309        {
 310            echo '
 311Conflicts:
 312'
 313                git ls-files --unmerged |
 314                sed -e 's/^[^   ]*      /       /' |
 315                uniq
 316        } >>"$GIT_DIR/MERGE_MSG"
 317        if test -d "$GIT_DIR/rr-cache"
 318        then
 319                git-rerere
 320        fi
 321        die "Automatic merge failed; fix up by hand"
 322fi