git-commit-vandalism/git-octopus-script
Junio C Hamano d9f3be7e2e [PATCH] Infamous 'octopus merge'
This script uses the list of heads and their origin multi-head "git
fetch" left in the $GIT_DIR/FETCH_HEAD file, and makes an octopus
merge on top of the current HEAD using them.

The implementation tries to be strict for the sake of safety.  It
insists that your working tree is clean (no local changes) and matches
the HEAD, and when any of the merged heads does not automerge, the
whole process is aborted and tries to rewind your working tree is to
the original state.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-24 16:50:51 -07:00

104 lines
2.5 KiB
Bash
Executable File

#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#
# Resolve two or more trees recorded in $GIT_DIR/FETCH_HEAD.
#
. git-sh-setup-script || die "Not a git archive"
usage () {
die "usage: git octopus"
}
# Sanity check the heads early.
while read SHA1 REPO
do
test $(git-cat-file -t $SHA1) = "commit" ||
die "$REPO given to octopus is not a commit"
done <"$GIT_DIR/FETCH_HEAD"
head=$(git-rev-parse --verify HEAD) || exit
git-update-cache --refresh ||
die "Your working tree is dirty."
test "$(git-diff-cache --cached "$head")" = "" ||
die "Your working tree does not match HEAD."
# MRC is the current "merge reference commit"
# MRT is the current "merge result tree"
MRC=$head MSG= PARENT="-p $head"
MRT=$(git-write-tree)
CNT=1 ;# counting our head
NON_FF_MERGE=0
while read SHA1 REPO
do
common=$(git-merge-base $MRC $SHA1) ||
die "Unable to find common commit with $SHA1 from $REPO"
if test "$common" = $SHA1
then
echo "Already up-to-date: $REPO"
continue
fi
CNT=`expr $CNT + 1`
PARENT="$PARENT -p $SHA1"
MSG="$MSG
$REPO"
if test "$common,$NON_FF_MERGE" = "$MRC,0"
then
# The first head being merged was a fast-forward.
# Advance MRC to the head being merged, and use that
# tree as the intermediate result of the merge.
# We still need to count this as part of the parent set.
echo "Fast forwarding to: $REPO"
git-read-tree -u -m $head $SHA1 || exit
MRC=$SHA1 MRT=$(git-write-tree)
continue
fi
NON_FF_MERGE=1
echo "Trying simple merge with $REPO"
git-read-tree -u -m $common $MRT $SHA1 || exit
next=$(git-write-tree 2>/dev/null)
if test $? -ne 0
then
echo "Simple merge did not work, trying automatic merge."
git-merge-cache -o git-merge-one-file-script -a || {
git-read-tree --reset "$head"
git-checkout-cache -f -q -u -a
die "Automatic merge failed; should not be doing Octopus"
}
next=$(git-write-tree 2>/dev/null)
fi
MRC=$common
MRT=$next
done <"$GIT_DIR/FETCH_HEAD"
# Just to be careful in case the user feeds nonsense to us.
case "$CNT" in
1)
echo "No changes."
exit 0 ;;
2)
echo "Not an Octopus; making an ordinary commit."
MSG="Merge "`expr "$MSG" : '. \(.*\)'` ; # remove LF and TAB
;;
*)
# In an octopus, the original head is just one of the equals,
# so we should list it as such.
HEAD_LINK=`readlink "$GIT_DIR/HEAD"`
MSG="Octopus merge of the following:
$HEAD_LINK from .$MSG"
;;
esac
result_commit=$(echo "$MSG" | git-commit-tree $MRT $PARENT)
echo "Committed merge $result_commit"
echo $result_commit >"$GIT_DIR"/HEAD
git-diff-tree -p $head $result_commit | git-apply --stat