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

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

LF='
'

# 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
91063bbc JH	11	# The first parameters up to -- are merge bases; the rest are heads.
	12	bases= head= remotes= sep_seen=
	13	for arg
	14	do
	15	case ",$sep_seen,$head,$arg," in
	16	*,--,)
	17	sep_seen=yes
	18	;;
	19	,yes,,*)
	20	head=$arg
	21	;;
	22	,yes,*)
	23	remotes="$remotes$arg "
	24	;;
	25	*)
	26	bases="$bases$arg "
	27	;;
	28	esac
	29	done
	30
	31	# Reject if this is not an Octopus -- resolve should be used instead.
	32	case "$remotes" in
	33	?' '?)
	34	;;
	35	*)
	36	exit 2 ;;
	37	esac
	38
	39	# MRC is the current "merge reference commit"
	40	# MRT is the current "merge result tree"
	41
	42	MRC=$head MSG= PARENT="-p $head"
	43	MRT=$(git-write-tree)
	44	CNT=1 ;# counting our head
	45	NON_FF_MERGE=0
	46	for SHA1 in $remotes
	47	do
17cf9397	48	common=$(git-merge-base --all $MRC $SHA1) \|\|
91063bbc JH	49	die "Unable to find common commit with $SHA1"
91063bbc JH	50
17cf9397 JH	51	case "$common" in
	52	?"$LF"?)
	53	die "Not trivially mergeable."
	54	;;
	55	$SHA1)
91063bbc JH	56	echo "Already up-to-date with $SHA1"
91063bbc JH	57	continue
17cf9397 JH	58	;;
17cf9397 JH	59	esac
91063bbc JH	60
	61	CNT=`expr $CNT + 1`
	62	PARENT="$PARENT -p $SHA1"
	63
	64	if test "$common,$NON_FF_MERGE" = "$MRC,0"
	65	then
	66	# The first head being merged was a fast-forward.
	67	# Advance MRC to the head being merged, and use that
	68	# tree as the intermediate result of the merge.
	69	# We still need to count this as part of the parent set.
	70
	71	echo "Fast forwarding to: $SHA1"
	72	git-read-tree -u -m $head $SHA1 \|\| exit
	73	MRC=$SHA1 MRT=$(git-write-tree)
	74	continue
	75	fi
	76
	77	NON_FF_MERGE=1
	78
	79	echo "Trying simple merge with $SHA1"
	80	git-read-tree -u -m $common $MRT $SHA1 \|\| exit 2
	81	next=$(git-write-tree 2>/dev/null)
	82	if test $? -ne 0
	83	then
	84	echo "Simple merge did not work, trying automatic merge."
	85	git-merge-index -o git-merge-one-file -a \|\|
	86	exit 2 ; # Automatic merge failed; should not be doing Octopus
	87	next=$(git-write-tree 2>/dev/null)
	88	fi
17cf9397 JH	89
	90	# We have merged the other branch successfully. Ideally
	91	# we could implement OR'ed heads in merge-base, and keep
	92	# a list of commits we have merged so far in MRC to feed
	93	# them to merge-base, but we approximate it by keep using
	94	# the current MRC. We used to update it to $common, which
	95	# was incorrectly doing AND'ed merge-base here, which was
	96	# unneeded.
	97
91063bbc JH	98	MRT=$next
	99	done
	100
	101	exit 0