Andrew's git - gitweb.git/blob

413bfcae9ffdf3d4545235e8000d8545e42e5384
   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 -- "$GIT_DIR/MERGE_HEAD" \
  23                 "$GIT_DIR/MERGE_SAVE" || exit 1
  24}
  25
  26savestate() {
  27        git diff -r -z --name-only $head | cpio -0 -o >"$GIR_DIR/MERGE_SAVE"
  28}
  29
  30restorestate() {
  31        git reset --hard $head
  32        cpio -iuv <"$GIT_DIR/MERGE_SAVE"
  33        git-update-index --refresh >/dev/null
  34}
  35
  36summary() {
  37        case "$no_summary" in
  38        '')
  39                git-diff-tree -p -M $head "$1" |
  40                git-apply --stat --summary
  41                ;;
  42        esac
  43}
  44
  45while case "$#" in 0) break ;; esac
  46do
  47        case "$1" in
  48        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
  49                --no-summa|--no-summar|--no-summary)
  50                no_summary=t ;;
  51        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
  52                --strateg=*|--strategy=*|\
  53        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
  54                case "$#,$1" in
  55                *,*=*)
  56                        strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
  57                1,*)
  58                        usage ;;
  59                *)
  60                        strategy="$2"
  61                        shift ;;
  62                esac
  63                case " $all_strategies " in
  64                *" $strategy "*)
  65                        use_strategies="$use_strategies$strategy " ;;
  66                *)
  67                        die "available strategies are: $all_strategies" ;;
  68                esac
  69                ;;
  70        -*)     usage ;;
  71        *)      break ;;
  72        esac
  73        shift
  74done
  75
  76case "$use_strategies" in
  77'')
  78        use_strategies=$default_strategies
  79        ;;
  80esac
  81test "$#" -le 2 && usage ;# we need at least two heads.
  82
  83merge_msg="$1"
  84shift
  85head_arg="$1"
  86head=$(git-rev-parse --verify "$1"^0) || usage
  87shift
  88
  89# All the rest are remote heads
  90for remote
  91do
  92        git-rev-parse --verify "$remote"^0 >/dev/null ||
  93            die "$remote - not something we can merge"
  94done
  95
  96common=$(git-show-branch --merge-base $head "$@")
  97echo "$head" >"$GIT_DIR/ORIG_HEAD"
  98
  99case "$#,$common" in
 100*,'')
 101        die "Unable to find common commit between $head_arg and $*"
 102        ;;
 1031,"$1")
 104        # If head can reach all the merge then we are up to date.
 105        # but first the most common case of merging one remote
 106        echo "Already up-to-date. Yeeah!"
 107        dropsave
 108        exit 0
 109        ;;
 1101,"$head")
 111        # Again the most common case of merging one remote.
 112        echo "Updating from $head to $1."
 113        git-update-index --refresh 2>/dev/null
 114        git-read-tree -u -m $head "$1" || exit 1
 115        git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD"
 116        summary "$1"
 117        dropsave
 118        exit 0
 119        ;;
 1201,*)
 121        # We are not doing octopus and not fast forward.  Need a
 122        # real merge.
 123        ;;
 124*)
 125        # An octopus.  If we can reach all the remote we are up to date.
 126        up_to_date=t
 127        for remote
 128        do
 129                common_one=$(git-merge-base $head $remote)
 130                if test "$common_one" != "$remote"
 131                then
 132                        up_to_date=f
 133                        break
 134                fi
 135        done
 136        if test "$up_to_date" = t
 137        then
 138                echo "Already up-to-date. Yeeah!"
 139                dropsave
 140                exit 0
 141        fi
 142        ;;
 143esac
 144
 145# At this point, we need a real merge.  No matter what strategy
 146# we use, it would operate on the index, possibly affecting the
 147# working tree, and when resolved cleanly, have the desired tree
 148# in the index -- this means that the index must be in sync with
 149# the $head commit.
 150files=$(git-diff-index --cached --name-only $head) || exit
 151if [ "$files" ]; then
 152   echo >&2 "Dirty index: cannot merge (dirty: $files)"
 153   exit 1
 154fi
 155
 156case "$use_strategies" in
 157?*' '?*)
 158    # Stash away the local changes so that we can try more than one.
 159    savestate
 160    single_strategy=no
 161    ;;
 162*)
 163    single_strategy=yes
 164    ;;
 165esac
 166
 167result_tree= best_cnt=-1 best_strategy= wt_strategy=
 168for strategy in $use_strategies
 169do
 170    test "$wt_strategy" = '' || {
 171        echo "Rewinding the tree to pristine..."
 172        restorestate
 173    }
 174    case "$single_strategy" in
 175    no)
 176        echo "Trying merge strategy $strategy..."
 177        ;;
 178    esac
 179
 180    # Remember which strategy left the state in the working tree
 181    wt_strategy=$strategy
 182
 183    git-merge-$strategy $common -- "$head_arg" "$@" || {
 184
 185        # The backend exits with 1 when conflicts are left to be resolved,
 186        # with 2 when it does not handle the given merge at all.
 187
 188        exit=$?
 189        if test "$exit" -eq 1
 190        then
 191            cnt=`{
 192                git-diff-files --name-only
 193                git-ls-files --unmerged
 194            } | wc -l`
 195            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 196            then
 197                best_strategy=$strategy
 198                best_cnt=$cnt
 199            fi
 200        fi
 201        continue
 202    }
 203
 204    # Automerge succeeded.
 205    result_tree=$(git-write-tree) && break
 206done
 207
 208# If we have a resulting tree, that means the strategy module
 209# auto resolved the merge cleanly.
 210if test '' != "$result_tree"
 211then
 212    parents="-p $head"
 213    for remote
 214    do
 215        parents="$parents -p $remote"
 216    done
 217    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents)
 218    echo "Committed merge $result_commit, made by $wt_strategy."
 219    echo $result_commit >"$GIT_DIR/HEAD"
 220    summary $result_commit
 221    dropsave
 222    exit 0
 223fi
 224
 225# Pick the result from the best strategy and have the user fix it up.
 226case "$best_strategy" in
 227'')
 228        restorestate
 229        die "No merge strategy handled the merge."
 230        ;;
 231"$wt_strategy")
 232        # We already have its result in the working tree.
 233        ;;
 234*)
 235        echo "Rewinding the tree to pristine..."
 236        restorestate
 237        echo "Using the $best_strategy to prepare resolving by hand."
 238        git-merge-$best_strategy $common -- "$head_arg" "$@"
 239        ;;
 240esac
 241for remote
 242do
 243        echo $remote
 244done >"$GIT_DIR/MERGE_HEAD"
 245die "Automatic merge failed; fix up by hand"