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=$(git rev-parse --verify -q $head)
  48 MRT=$(git write-tree)
  49 NON_FF_MERGE=0
  50 OCTOPUS_FAILURE=0
  51 for SHA1 in $remotes
  52 do
  53         case "$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
 107 done
 108
 109 exit "$OCTOPUS_FAILURE"