Andrew's git / gitweb.git / git-merge.sh
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git-merge.shon commit [PATCH] fetch.c: Make process() look at each object only once (a82d07e)
   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
  21dropheads() {
  22        rm -f -- "$GIT_DIR/MERGE_HEAD" || exit 1
  23}
  24
  25summary() {
  26        case "$no_summary" in
  27        '')
  28                git-diff-tree -p -M $head "$1" |
  29                git-apply --stat --summary
  30                ;;
  31        esac
  32}
  33
  34while case "$#" in 0) break ;; esac
  35do
  36        case "$1" in
  37        -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
  38                --no-summa|--no-summar|--no-summary)
  39                no_summary=t ;;
  40        -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
  41                --strateg=*|--strategy=*|\
  42        -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
  43                case "$#,$1" in
  44                *,*=*)
  45                        strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
  46                1,*)
  47                        usage ;;
  48                *)
  49                        strategy="$2"
  50                        shift ;;
  51                esac
  52                case " $all_strategies " in
  53                *" $strategy "*)
  54                        use_strategies="$use_strategies$strategy " ;;
  55                *)
  56                        die "available strategies are: $all_strategies" ;;
  57                esac
  58                ;;
  59        -*)     usage ;;
  60        *)      break ;;
  61        esac
  62        shift
  63done
  64
  65case "$use_strategies" in
  66'')
  67        use_strategies=$default_strategies
  68        ;;
  69esac
  70test "$#" -le 2 && usage ;# we need at least two heads.
  71
  72merge_msg="$1"
  73shift
  74head=$(git-rev-parse --verify "$1"^0) || usage
  75shift
  76
  77# All the rest are remote heads
  78for remote
  79do
  80        git-rev-parse --verify "$remote"^0 >/dev/null ||
  81            die "$remote - not something we can merge"
  82done
  83
  84common=$(git-show-branch --merge-base $head "$@")
  85echo "$head" >"$GIT_DIR/ORIG_HEAD"
  86
  87case "$#,$common" in
  88*,'')
  89        die "Unable to find common commit between $head and $*"
  90        ;;
  911,"$1")
  92        # If head can reach all the merge then we are up to date.
  93        # but first the most common case of merging one remote
  94        echo "Already up-to-date. Yeeah!"
  95        dropheads
  96        exit 0
  97        ;;
  981,"$head")
  99        # Again the most common case of merging one remote.
 100        echo "Updating from $head to $1."
 101        git-update-index --refresh 2>/dev/null
 102        git-read-tree -u -m $head "$1" || exit 1
 103        git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD"
 104        summary "$1"
 105        dropheads
 106        exit 0
 107        ;;
 1081,*)
 109        # We are not doing octopus and not fast forward.  Need a
 110        # real merge.
 111        ;;
 112*)
 113        # An octopus.  If we can reach all the remote we are up to date.
 114        up_to_date=t
 115        for remote
 116        do
 117                common_one=$(git-merge-base $head $remote)
 118                if test "$common_one" != "$remote"
 119                then
 120                        up_to_date=f
 121                        break
 122                fi
 123        done
 124        if test "$up_to_date" = t
 125        then
 126                echo "Already up-to-date. Yeeah!"
 127                dropheads
 128                exit 0
 129        fi
 130        ;;
 131esac
 132
 133# At this point we need a real merge.  Require that the tree matches
 134# exactly our head.
 135
 136git-update-index --refresh &&
 137test '' = "`git-diff-index --cached --name-only $head`" || {
 138        die "Need real merge but the working tree has local changes."
 139}
 140
 141result_tree= best_cnt=-1 best_strategy= wt_strategy=
 142for strategy in $use_strategies
 143do
 144    test "$wt_strategy" = '' || {
 145        echo "Rewinding the tree to pristine..."
 146        git reset --hard $head
 147    }
 148    echo "Trying merge strategy $strategy..."
 149    wt_strategy=$strategy
 150    git-merge-$strategy $common -- $head "$@" || {
 151
 152        # The backend exits with 1 when conflicts are left to be resolved,
 153        # with 2 when it does not handle the given merge at all.
 154
 155        exit=$?
 156        if test "$exit" -eq 1
 157        then
 158            cnt=`{
 159                git-diff-files --name-only
 160                git-ls-files --unmerged
 161            } | wc -l`
 162            if test $best_cnt -le 0 -o $cnt -le $best_cnt
 163            then
 164                best_strategy=$strategy
 165                best_cnt=$cnt
 166            fi
 167        fi
 168        continue
 169    }
 170
 171    # Automerge succeeded.
 172    result_tree=$(git-write-tree) && break
 173done
 174
 175# If we have a resulting tree, that means the strategy module
 176# auto resolved the merge cleanly.
 177if test '' != "$result_tree"
 178then
 179    parents="-p $head"
 180    for remote
 181    do
 182        parents="$parents -p $remote"
 183    done
 184    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents)
 185    echo "Committed merge $result_commit, made by $wt_strategy."
 186    echo $result_commit >"$GIT_DIR/HEAD"
 187    summary $result_commit
 188    dropheads
 189    exit 0
 190fi
 191
 192# Pick the result from the best strategy and have the user fix it up.
 193case "$best_strategy" in
 194'')
 195        git reset --hard $head
 196        die "No merge strategy handled the merge."
 197        ;;
 198"$wt_strategy")
 199        # We already have its result in the working tree.
 200        ;;
 201*)
 202        echo "Rewinding the tree to pristine..."
 203        git reset --hard $head
 204        echo "Using the $best_strategy to prepare resolving by hand."
 205        git-merge-$best_strategy $common -- $head "$@"
 206        ;;
 207esac
 208for remote
 209do
 210        echo $remote
 211done >"$GIT_DIR/MERGE_HEAD"
 212die "Automatic merge failed; fix up by hand"