Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5
   6. git-sh-setup || die "Not a git archive"
   7
   8LF='
   9'
  10
  11usage () {
  12    die "git-merge [-n] [-s <strategy>]... <merge-message> <head> <remote>+"
  13}
  14
  15# all_strategies='resolve recursive stupid octopus'
  16
  17all_strategies='recursive octopus resolve stupid'
  18default_strategies='resolve octopus'
  19use_strategies=
  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 -r -z --name-only $head |
  29        cpio -0 -o >"$GIR_DIR/MERGE_SAVE"
  30}
  31
  32restorestate() {
  33        if test -f "$GIT_DIR/MERGE_SAVE"
  34        then
  35                git reset --hard $head
  36                cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  37                git-update-index --refresh >/dev/null
  38        fi
  39}
  40
  41summary() {
  42        case "$no_summary" in
  43        '')
  44                git-diff-tree -p -M $head "$1" |
  45                git-apply --stat --summary
  46                ;;
  47        esac
  48}
  49
  50while case "$#" in 0) break ;; esac
  51do
  52        case "$1" in
  53        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
  54                --no-summa|--no-summar|--no-summary)
  55                no_summary=t ;;
  56        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
  57                --strateg=*|--strategy=*|\
  58        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
  59                case "$#,$1" in
  60                *,*=*)
  61                        strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
  62                1,*)
  63                        usage ;;
  64                *)
  65                        strategy="$2"
  66                        shift ;;
  67                esac
  68                case " $all_strategies " in
  69                *" $strategy "*)
  70                        use_strategies="$use_strategies$strategy " ;;
  71                *)
  72                        die "available strategies are: $all_strategies" ;;
  73                esac
  74                ;;
  75        -*)     usage ;;
  76        *)      break ;;
  77        esac
  78        shift
  79done
  80
  81case "$use_strategies" in
  82'')
  83        use_strategies=$default_strategies
  84        ;;
  85esac
  86test "$#" -le 2 && usage ;# we need at least two heads.
  87
  88merge_msg="$1"
  89shift
  90head_arg="$1"
  91head=$(git-rev-parse --verify "$1"^0) || usage
  92shift
  93
  94# All the rest are remote heads
  95for remote
  96do
  97        git-rev-parse --verify "$remote"^0 >/dev/null ||
  98            die "$remote - not something we can merge"
  99done
 100
 101common=$(git-show-branch --merge-base $head "$@")
 102echo "$head" >"$GIT_DIR/ORIG_HEAD"
 103
 104case "$#,$common" in
 105*,'')
 106        die "Unable to find common commit between $head_arg and $*"
 107        ;;
 1081,"$1")
 109        # If head can reach all the merge then we are up to date.
 110        # but first the most common case of merging one remote
 111        echo "Already up-to-date. Yeeah!"
 112        dropsave
 113        exit 0
 114        ;;
 1151,"$head")
 116        # Again the most common case of merging one remote.
 117        echo "Updating from $head to $1."
 118        git-update-index --refresh 2>/dev/null
 119        git-read-tree -u -m $head "$1" &&
 120        new_head=$(git-rev-parse --verify "$1^0") &&
 121        git-update-ref HEAD "$new_head" "$head" || exit 1
 122        summary "$1"
 123        dropsave
 124        exit 0
 125        ;;
 1261,*)
 127        # We are not doing octopus and not fast forward.  Need a
 128        # real merge.
 129        ;;
 130*)
 131        # An octopus.  If we can reach all the remote we are up to date.
 132        up_to_date=t
 133        for remote
 134        do
 135                common_one=$(git-merge-base $head $remote)
 136                if test "$common_one" != "$remote"
 137                then
 138                        up_to_date=f
 139                        break
 140                fi
 141        done
 142        if test "$up_to_date" = t
 143        then
 144                echo "Already up-to-date. Yeeah!"
 145                dropsave
 146                exit 0
 147        fi
 148        ;;
 149esac
 150
 151# At this point, we need a real merge.  No matter what strategy
 152# we use, it would operate on the index, possibly affecting the
 153# working tree, and when resolved cleanly, have the desired tree
 154# in the index -- this means that the index must be in sync with
 155# the $head commit.  The strategies are responsible to ensure this.
 156
 157case "$use_strategies" in
 158?*' '?*)
 159    # Stash away the local changes so that we can try more than one.
 160    savestate
 161    single_strategy=no
 162    ;;
 163*)
 164    rm -f "$GIT_DIR/MERGE_SAVE"
 165    single_strategy=yes
 166    ;;
 167esac
 168
 169result_tree= best_cnt=-1 best_strategy= wt_strategy=
 170for strategy in $use_strategies
 171do
 172    test "$wt_strategy" = '' || {
 173        echo "Rewinding the tree to pristine..."
 174        restorestate
 175    }
 176    case "$single_strategy" in
 177    no)
 178        echo "Trying merge strategy $strategy..."
 179        ;;
 180    esac
 181
 182    # Remember which strategy left the state in the working tree
 183    wt_strategy=$strategy
 184
 185    git-merge-$strategy $common -- "$head_arg" "$@" || {
 186
 187        # The backend exits with 1 when conflicts are left to be resolved,
 188        # with 2 when it does not handle the given merge at all.
 189
 190        exit=$?
 191        if test "$exit" -eq 1
 192        then
 193            cnt=`{
 194                git-diff-files --name-only
 195                git-ls-files --unmerged
 196            } | wc -l`
 197            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 198            then
 199                best_strategy=$strategy
 200                best_cnt=$cnt
 201            fi
 202        fi
 203        continue
 204    }
 205
 206    # Automerge succeeded.
 207    result_tree=$(git-write-tree) && break
 208done
 209
 210# If we have a resulting tree, that means the strategy module
 211# auto resolved the merge cleanly.
 212if test '' != "$result_tree"
 213then
 214    parents="-p $head"
 215    for remote
 216    do
 217        parents="$parents -p $remote"
 218    done
 219    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
 220    echo "Committed merge $result_commit, made by $wt_strategy."
 221    git-update-ref HEAD $result_commit $head
 222    summary $result_commit
 223    dropsave
 224    exit 0
 225fi
 226
 227# Pick the result from the best strategy and have the user fix it up.
 228case "$best_strategy" in
 229'')
 230        restorestate
 231        die "No merge strategy handled the merge."
 232        ;;
 233"$wt_strategy")
 234        # We already have its result in the working tree.
 235        ;;
 236*)
 237        echo "Rewinding the tree to pristine..."
 238        restorestate
 239        echo "Using the $best_strategy to prepare resolving by hand."
 240        git-merge-$best_strategy $common -- "$head_arg" "$@"
 241        ;;
 242esac
 243for remote
 244do
 245        echo $remote
 246done >"$GIT_DIR/MERGE_HEAD"
 247echo $merge_msg >"$GIT_DIR/MERGE_MSG"
 248
 249die "Automatic merge failed; fix up by hand"