[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
OCTOPUS_FAILURE=0
for SHA1 in $remotes
do
	case "$OCTOPUS_FAILURE" in
	1)
		# We allow only last one to have a hand-resolvable
		# conflicts.  Last round failed and we still had
		# a head to merge.
		echo "Automated merge did not work."
		echo "Should not be doing an Octopus."
		exit 2
	esac

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

	case "$LF$common$LF" in
	*"$LF$SHA1$LF"*)
		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 $? -ne 0
	then
		echo "Simple merge did not work, trying automatic merge."
		git-merge-index -o git-merge-one-file -a ||
		OCTOPUS_FAILURE=1
		next=$(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 "$OCTOPUS_FAILURE"
Commit	Line	Data
91063bbc JH	1	#!/bin/sh
	2	#
	3	# Copyright (c) 2005 Junio C Hamano
	4	#
	5	# Resolve two or more trees.
	6	#
	7
17cf9397 JH	8	LF='
	9	'
	10
d165fa14 JH	11	die () {
	12	echo >&2 "$*"
	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
98efc8f3	51	OCTOPUS_FAILURE=0
91063bbc JH	52	for SHA1 in $remotes
91063bbc JH	53	do
98efc8f3 JH	54	case "$OCTOPUS_FAILURE" in
	55	1)
	56	# We allow only last one to have a hand-resolvable
	57	# conflicts. Last round failed and we still had
	58	# a head to merge.
	59	echo "Automated merge did not work."
	60	echo "Should not be doing an Octopus."
	61	exit 2
	62	esac
	63
17cf9397	64	common=$(git-merge-base --all $MRC $SHA1) \|\|
91063bbc JH	65	die "Unable to find common commit with $SHA1"
91063bbc JH	66
c884dd9a JH	67	case "$LF$common$LF" in
c884dd9a JH	68	"$LF$SHA1$LF")
91063bbc JH	69	echo "Already up-to-date with $SHA1"
91063bbc JH	70	continue
17cf9397 JH	71	;;
17cf9397 JH	72	esac
91063bbc JH	73
	74	CNT=`expr $CNT + 1`
	75	PARENT="$PARENT -p $SHA1"
	76
	77	if test "$common,$NON_FF_MERGE" = "$MRC,0"
	78	then
	79	# The first head being merged was a fast-forward.
	80	# Advance MRC to the head being merged, and use that
	81	# tree as the intermediate result of the merge.
	82	# We still need to count this as part of the parent set.
	83
	84	echo "Fast forwarding to: $SHA1"
	85	git-read-tree -u -m $head $SHA1 \|\| exit
	86	MRC=$SHA1 MRT=$(git-write-tree)
	87	continue
	88	fi
	89
	90	NON_FF_MERGE=1
	91
	92	echo "Trying simple merge with $SHA1"
	93	git-read-tree -u -m $common $MRT $SHA1 \|\| exit 2
	94	next=$(git-write-tree 2>/dev/null)
	95	if test $? -ne 0
	96	then
	97	echo "Simple merge did not work, trying automatic merge."
98efc8f3 JH	98	git-merge-index -o git-merge-one-file -a \|\|
98efc8f3 JH	99	OCTOPUS_FAILURE=1
91063bbc JH	100	next=$(git-write-tree 2>/dev/null)
91063bbc JH	101	fi
17cf9397 JH	102
	103	# We have merged the other branch successfully. Ideally
	104	# we could implement OR'ed heads in merge-base, and keep
	105	# a list of commits we have merged so far in MRC to feed
	106	# them to merge-base, but we approximate it by keep using
	107	# the current MRC. We used to update it to $common, which
	108	# was incorrectly doing AND'ed merge-base here, which was
	109	# unneeded.
	110
91063bbc JH	111	MRT=$next
	112	done
	113
98efc8f3	114	exit "$OCTOPUS_FAILURE"