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 if ! git diff-index --quiet --cached HEAD --
  48 then
  49     echo "Error: Your local changes to the following files would be overwritten by merge"
  50     git diff-index --cached --name-only HEAD -- | sed -e 's/^/    /'
  51     exit 2
  52 fi
  53 MRC=$(git rev-parse --verify -q $head)
  54 MRT=$(git write-tree)
  55 NON_FF_MERGE=0
  56 OCTOPUS_FAILURE=0
  57 for SHA1 in $remotes
  58 do
  59         case "$OCTOPUS_FAILURE" in
  60         1)
  61                 # We allow only last one to have a hand-resolvable
  62                 # conflicts.  Last round failed and we still had
  63                 # a head to merge.
  64                 echo "Automated merge did not work."
  65                 echo "Should not be doing an Octopus."
  66                 exit 2
  67         esac
  68
  69         eval pretty_name=\${GITHEAD_$SHA1:-$SHA1}
  70         if test "$SHA1" = "$pretty_name"
  71         then
  72                 SHA1_UP="$(echo "$SHA1" | tr a-z A-Z)"
  73                 eval pretty_name=\${GITHEAD_$SHA1_UP:-$pretty_name}
  74         fi
  75         common=$(git merge-base --all $SHA1 $MRC) ||
  76                 die "Unable to find common commit with $pretty_name"
  77
  78         case "$LF$common$LF" in
  79         *"$LF$SHA1$LF"*)
  80                 echo "Already up-to-date with $pretty_name"
  81                 continue
  82                 ;;
  83         esac
  84
  85         if test "$common,$NON_FF_MERGE" = "$MRC,0"
  86         then
  87                 # The first head being merged was a fast-forward.
  88                 # Advance MRC to the head being merged, and use that
  89                 # tree as the intermediate result of the merge.
  90                 # We still need to count this as part of the parent set.
  91
  92                 echo "Fast-forwarding to: $pretty_name"
  93                 git read-tree -u -m $head $SHA1 || exit
  94                 MRC=$SHA1 MRT=$(git write-tree)
  95                 continue
  96         fi
  97
  98         NON_FF_MERGE=1
  99
 100         echo "Trying simple merge with $pretty_name"
 101         git read-tree -u -m --aggressive  $common $MRT $SHA1 || exit 2
 102         next=$(git write-tree 2>/dev/null)
 103         if test $? -ne 0
 104         then
 105                 echo "Simple merge did not work, trying automatic merge."
 106                 git-merge-index -o git-merge-one-file -a ||
 107                 OCTOPUS_FAILURE=1
 108                 next=$(git write-tree 2>/dev/null)
 109         fi
 110
 111         MRC="$MRC $SHA1"
 112         MRT=$next
 113 done
 114
 115 exit "$OCTOPUS_FAILURE"