Andrew's git - gitweb.git/blob - git-merge-octopus.sh

   1#!/bin/sh
   2#
   3# Copyright (c) 2005 Junio C Hamano
   4#
   5# Resolve two or more trees.
   6#
   7
   8LF='
   9'
  10
  11die () {
  12    echo >&2 "$*"
  13    exit 1
  14}
  15
  16# The first parameters up to -- are merge bases; the rest are heads.
  17bases= head= remotes= sep_seen=
  18for arg
  19do
  20        case ",$sep_seen,$head,$arg," in
  21        *,--,)
  22                sep_seen=yes
  23                ;;
  24        ,yes,,*)
  25                head=$arg
  26                ;;
  27        ,yes,*)
  28                remotes="$remotes$arg "
  29                ;;
  30        *)
  31                bases="$bases$arg "
  32                ;;
  33        esac
  34done
  35
  36# Reject if this is not an Octopus -- resolve should be used instead.
  37case "$remotes" in
  38?*' '?*)
  39        ;;
  40*)
  41        exit 2 ;;
  42esac
  43
  44# MRC is the current "merge reference commit"
  45# MRT is the current "merge result tree"
  46
  47MRC=$head MSG= PARENT="-p $head"
  48MRT=$(git-write-tree)
  49CNT=1 ;# counting our head
  50NON_FF_MERGE=0
  51for SHA1 in $remotes
  52do
  53        common=$(git-merge-base --all $MRC $SHA1) ||
  54                die "Unable to find common commit with $SHA1"
  55
  56        case "$common" in
  57        ?*"$LF"?*)
  58                die "Not trivially mergeable."
  59                ;;
  60        $SHA1)
  61                echo "Already up-to-date with $SHA1"
  62                continue
  63                ;;
  64        esac
  65
  66        CNT=`expr $CNT + 1`
  67        PARENT="$PARENT -p $SHA1"
  68
  69        if test "$common,$NON_FF_MERGE" = "$MRC,0"
  70        then
  71                # The first head being merged was a fast-forward.
  72                # Advance MRC to the head being merged, and use that
  73                # tree as the intermediate result of the merge.
  74                # We still need to count this as part of the parent set.
  75
  76                echo "Fast forwarding to: $SHA1"
  77                git-read-tree -u -m $head $SHA1 || exit
  78                MRC=$SHA1 MRT=$(git-write-tree)
  79                continue
  80        fi
  81
  82        NON_FF_MERGE=1
  83
  84        echo "Trying simple merge with $SHA1"
  85        git-read-tree -u -m $common $MRT $SHA1 || exit 2
  86        next=$(git-write-tree 2>/dev/null)
  87        if test $? -ne 0
  88        then
  89                echo "Simple merge did not work, trying automatic merge."
  90                git-merge-index -o git-merge-one-file -a ||
  91                exit 2 ; # Automatic merge failed; should not be doing Octopus
  92                next=$(git-write-tree 2>/dev/null)
  93        fi
  94
  95        # We have merged the other branch successfully.  Ideally
  96        # we could implement OR'ed heads in merge-base, and keep
  97        # a list of commits we have merged so far in MRC to feed
  98        # them to merge-base, but we approximate it by keep using
  99        # the current MRC.  We used to update it to $common, which
 100        # was incorrectly doing AND'ed merge-base here, which was
 101        # unneeded.
 102
 103        MRT=$next
 104done
 105
 106exit 0