git-merge-octopus.shon commit commit: allow associating auxiliary info on-demand (96c4f4a)
   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=$(git rev-parse --verify -q $head)
  48MRT=$(git write-tree)
  49NON_FF_MERGE=0
  50OCTOPUS_FAILURE=0
  51for SHA1 in $remotes
  52do
  53        case "$OCTOPUS_FAILURE" in
  54        1)
  55                # We allow only last one to have a hand-resolvable
  56                # conflicts.  Last round failed and we still had
  57                # a head to merge.
  58                echo "Automated merge did not work."
  59                echo "Should not be doing an Octopus."
  60                exit 2
  61        esac
  62
  63        eval pretty_name=\${GITHEAD_$SHA1:-$SHA1}
  64        if test "$SHA1" = "$pretty_name"
  65        then
  66                SHA1_UP="$(echo "$SHA1" | tr a-z A-Z)"
  67                eval pretty_name=\${GITHEAD_$SHA1_UP:-$pretty_name}
  68        fi
  69        common=$(git merge-base --all $SHA1 $MRC) ||
  70                die "Unable to find common commit with $pretty_name"
  71
  72        case "$LF$common$LF" in
  73        *"$LF$SHA1$LF"*)
  74                echo "Already up-to-date with $pretty_name"
  75                continue
  76                ;;
  77        esac
  78
  79        if test "$common,$NON_FF_MERGE" = "$MRC,0"
  80        then
  81                # The first head being merged was a fast-forward.
  82                # Advance MRC to the head being merged, and use that
  83                # tree as the intermediate result of the merge.
  84                # We still need to count this as part of the parent set.
  85
  86                echo "Fast-forwarding to: $pretty_name"
  87                git read-tree -u -m $head $SHA1 || exit
  88                MRC=$SHA1 MRT=$(git write-tree)
  89                continue
  90        fi
  91
  92        NON_FF_MERGE=1
  93
  94        echo "Trying simple merge with $pretty_name"
  95        git read-tree -u -m --aggressive  $common $MRT $SHA1 || exit 2
  96        next=$(git write-tree 2>/dev/null)
  97        if test $? -ne 0
  98        then
  99                echo "Simple merge did not work, trying automatic merge."
 100                git-merge-index -o git-merge-one-file -a ||
 101                OCTOPUS_FAILURE=1
 102                next=$(git write-tree 2>/dev/null)
 103        fi
 104
 105        MRC="$MRC $SHA1"
 106        MRT=$next
 107done
 108
 109exit "$OCTOPUS_FAILURE"