[thirdparty/git.git] / git-merge-octopus.sh

#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#
# Resolve two or more trees.
#

LF='
'

die () {
    echo >&2 "$*"
    exit 1
}

# The first parameters up to -- are merge bases; the rest are heads.
bases= head= remotes= sep_seen=
for arg
do
	case ",$sep_seen,$head,$arg," in
	*,--,)
		sep_seen=yes
		;;
	,yes,,*)
		head=$arg
		;;
	,yes,*)
		remotes="$remotes$arg "
		;;
	*)
		bases="$bases$arg "
		;;
	esac
done

# Reject if this is not an Octopus -- resolve should be used instead.
case "$remotes" in
?*' '?*)
	;;
*)
	exit 2 ;;
esac

# 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
for SHA1 in $remotes
do
	common=$(git-merge-base --all $MRC $SHA1) ||
		die "Unable to find common commit with $SHA1"

	case "$common" in
	?*"$LF"?*)
		die "Not trivially mergeable."
		;;
	$SHA1)
		echo "Already up-to-date with $SHA1"
		continue
		;;
	esac

	CNT=`expr $CNT + 1`
	PARENT="$PARENT -p $SHA1"

	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: $SHA1"
		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 $SHA1"
	git-read-tree -u -m $common $MRT $SHA1 || exit 2
	next=$(git-write-tree 2>/dev/null)
	if test $? -ne 0
	then
		echo "Simple merge did not work, trying automatic merge."
		git-merge-index -o git-merge-one-file -a ||
		exit 2 ; # Automatic merge failed; should not be doing Octopus
		next=$(git-write-tree 2>/dev/null)
	fi

	# We have merged the other branch successfully.  Ideally
	# we could implement OR'ed heads in merge-base, and keep
	# a list of commits we have merged so far in MRC to feed
	# them to merge-base, but we approximate it by keep using
	# the current MRC.  We used to update it to $common, which
	# was incorrectly doing AND'ed merge-base here, which was
	# unneeded.

	MRT=$next
done

exit 0
Commit	Line	Data
91063bbc JH	1	#!/bin/sh
	2	#
	3	# Copyright (c) 2005 Junio C Hamano
	4	#
	5	# Resolve two or more trees.
	6	#
	7
17cf9397 JH	8	LF='
	9	'
	10
d165fa14 JH	11	die () {
	12	echo >&2 "$*"
	13	exit 1
	14	}
	15
91063bbc JH	16	# The first parameters up to -- are merge bases; the rest are heads.
	17	bases= head= remotes= sep_seen=
	18	for arg
	19	do
	20	case ",$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	for SHA1 in $remotes
	52	do
17cf9397	53	common=$(git-merge-base --all $MRC $SHA1) \|\|
91063bbc JH	54	die "Unable to find common commit with $SHA1"
91063bbc JH	55
17cf9397 JH	56	case "$common" in
	57	?"$LF"?)
	58	die "Not trivially mergeable."
	59	;;
	60	$SHA1)
91063bbc JH	61	echo "Already up-to-date with $SHA1"
91063bbc JH	62	continue
17cf9397 JH	63	;;
17cf9397 JH	64	esac
91063bbc JH	65
	66	CNT=`expr $CNT + 1`
	67	PARENT="$PARENT -p $SHA1"
	68
	69	if test "$common,$NON_FF_MERGE" = "$MRC,0"
	70	then
	71	# The first head being merged was a fast-forward.
	72	# Advance MRC to the head being merged, and use that
	73	# tree as the intermediate result of the merge.
	74	# We still need to count this as part of the parent set.
	75
	76	echo "Fast forwarding to: $SHA1"
	77	git-read-tree -u -m $head $SHA1 \|\| exit
	78	MRC=$SHA1 MRT=$(git-write-tree)
	79	continue
	80	fi
	81
	82	NON_FF_MERGE=1
	83
	84	echo "Trying simple merge with $SHA1"
	85	git-read-tree -u -m $common $MRT $SHA1 \|\| exit 2
	86	next=$(git-write-tree 2>/dev/null)
	87	if test $? -ne 0
	88	then
	89	echo "Simple merge did not work, trying automatic merge."
	90	git-merge-index -o git-merge-one-file -a \|\|
	91	exit 2 ; # Automatic merge failed; should not be doing Octopus
	92	next=$(git-write-tree 2>/dev/null)
	93	fi
17cf9397 JH	94
	95	# We have merged the other branch successfully. Ideally
	96	# we could implement OR'ed heads in merge-base, and keep
	97	# a list of commits we have merged so far in MRC to feed
	98	# them to merge-base, but we approximate it by keep using
	99	# the current MRC. We used to update it to $common, which
	100	# was incorrectly doing AND'ed merge-base here, which was
	101	# unneeded.
	102
91063bbc JH	103	MRT=$next
	104	done
	105
	106	exit 0