git-octopus.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano
   4 #
   5 # Resolve two or more trees recorded in $GIT_DIR/FETCH_HEAD.
   6 #
   7 . git-sh-setup || die "Not a git archive"
   8
   9 usage () {
  10     die "usage: git octopus"
  11 }
  12
  13 # Sanity check the heads early.
  14 while read SHA1 REPO
  15 do
  16         test $(git-cat-file -t $SHA1) = "commit" ||
  17                 die "$REPO given to octopus is not a commit"
  18 done <"$GIT_DIR/FETCH_HEAD"
  19
  20 head=$(git-rev-parse --verify HEAD) || exit
  21
  22 git-update-index --refresh ||
  23         die "Your working tree is dirty."
  24 test "$(git-diff-index --cached "$head")" = "" ||
  25         die "Your working tree does not match HEAD."
  26
  27 # MRC is the current "merge reference commit"
  28 # MRT is the current "merge result tree"
  29
  30 MRC=$head MSG= PARENT="-p $head"
  31 MRT=$(git-write-tree)
  32 CNT=1 ;# counting our head
  33 NON_FF_MERGE=0
  34 while read SHA1 REPO
  35 do
  36         common=$(git-merge-base $MRC $SHA1) ||
  37                 die "Unable to find common commit with $SHA1 from $REPO"
  38
  39         if test "$common" = $SHA1
  40         then
  41                 echo "Already up-to-date: $REPO"
  42                 continue
  43         fi
  44
  45         CNT=`expr $CNT + 1`
  46         PARENT="$PARENT -p $SHA1"
  47         MSG="$MSG
  48         $REPO"
  49
  50         if test "$common,$NON_FF_MERGE" = "$MRC,0"
  51         then
  52                 # The first head being merged was a fast-forward.
  53                 # Advance MRC to the head being merged, and use that
  54                 # tree as the intermediate result of the merge.
  55                 # We still need to count this as part of the parent set.
  56
  57                 echo "Fast forwarding to: $REPO"
  58                 git-read-tree -u -m $head $SHA1 || exit
  59                 MRC=$SHA1 MRT=$(git-write-tree)
  60                 continue
  61         fi
  62
  63         NON_FF_MERGE=1
  64
  65         echo "Trying simple merge with $REPO"
  66         git-read-tree -u -m $common $MRT $SHA1 || exit
  67         next=$(git-write-tree 2>/dev/null)
  68         if test $? -ne 0
  69         then
  70                 echo "Simple merge did not work, trying automatic merge."
  71                 git-merge-index -o git-merge-one-file -a || {
  72                 git-read-tree --reset "$head"
  73                 git-checkout-index -f -q -u -a
  74                 die "Automatic merge failed; should not be doing Octopus"
  75                 }
  76                 next=$(git-write-tree 2>/dev/null)
  77         fi
  78         MRC=$common
  79         MRT=$next
  80 done <"$GIT_DIR/FETCH_HEAD"
  81
  82 # Just to be careful in case the user feeds nonsense to us.
  83 case "$CNT" in
  84 1)
  85         echo "No changes."
  86         exit 0 ;;
  87 2)
  88         echo "Not an Octopus; making an ordinary commit."
  89         MSG="Merge "`expr "$MSG" : '.   \(.*\)'` ; # remove LF and TAB
  90         ;;
  91 *)
  92         # In an octopus, the original head is just one of the equals,
  93         # so we should list it as such.
  94         HEAD_LINK=`readlink "$GIT_DIR/HEAD"`
  95         MSG="Octopus merge of the following:
  96
  97         $HEAD_LINK from .$MSG"
  98         ;;
  99 esac
 100 result_commit=$(echo "$MSG" | git-commit-tree $MRT $PARENT)
 101 echo "Committed merge $result_commit"
 102 echo $result_commit >"$GIT_DIR"/HEAD
 103 git-diff-tree -p $head $result_commit | git-apply --stat