git-merge-octopus.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano
   4 #
   5 # Resolve two or more trees.
   6 #
   7
   8 LF='
   9 '
  10
  11 die () {
  12     echo >&2 "$*"
  13     exit 1
  14 }
  15
  16 # The first parameters up to -- are merge bases; the rest are heads.
  17 bases= head= remotes= sep_seen=
  18 for arg
  19 do
  20         case ",$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$arg "
  32                 ;;
  33         esac
  34 done
  35
  36 # Reject if this is not an Octopus -- resolve should be used instead.
  37 case "$remotes" in
  38 ?*' '?*)
  39         ;;
  40 *)
  41         exit 2 ;;
  42 esac
  43
  44 # MRC is the current "merge reference commit"
  45 # MRT is the current "merge result tree"
  46
  47 MRC=$head MSG= PARENT="-p $head"
  48 MRT=$(git write-tree)
  49 CNT=1 ;# counting our head
  50 NON_FF_MERGE=0
  51 OCTOPUS_FAILURE=0
  52 for SHA1 in $remotes
  53 do
  54         case "$OCTOPUS_FAILURE" in
  55         1)
  56                 # We allow only last one to have a hand-resolvable
  57                 # conflicts.  Last round failed and we still had
  58                 # a head to merge.
  59                 echo "Automated merge did not work."
  60                 echo "Should not be doing an Octopus."
  61                 exit 2
  62         esac
  63
  64         eval pretty_name=\${GITHEAD_$SHA1:-$SHA1}
  65         common=$(git merge-base --all $SHA1 $MRC) ||
  66                 die "Unable to find common commit with $pretty_name"
  67
  68         case "$LF$common$LF" in
  69         *"$LF$SHA1$LF"*)
  70                 echo "Already up-to-date with $pretty_name"
  71                 continue
  72                 ;;
  73         esac
  74
  75         CNT=`expr $CNT + 1`
  76         PARENT="$PARENT -p $SHA1"
  77
  78         if test "$common,$NON_FF_MERGE" = "$MRC,0"
  79         then
  80                 # The first head being merged was a fast-forward.
  81                 # Advance MRC to the head being merged, and use that
  82                 # tree as the intermediate result of the merge.
  83                 # We still need to count this as part of the parent set.
  84
  85                 echo "Fast-forwarding to: $pretty_name"
  86                 git read-tree -u -m $head $SHA1 || exit
  87                 MRC=$SHA1 MRT=$(git write-tree)
  88                 continue
  89         fi
  90
  91         NON_FF_MERGE=1
  92
  93         echo "Trying simple merge with $pretty_name"
  94         git read-tree -u -m --aggressive  $common $MRT $SHA1 || exit 2
  95         next=$(git write-tree 2>/dev/null)
  96         if test $? -ne 0
  97         then
  98                 echo "Simple merge did not work, trying automatic merge."
  99                 git-merge-index -o git-merge-one-file -a ||
 100                 OCTOPUS_FAILURE=1
 101                 next=$(git write-tree 2>/dev/null)
 102         fi
 103
 104         MRC="$MRC $SHA1"
 105         MRT=$next
 106 done
 107
 108 exit "$OCTOPUS_FAILURE"