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

#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#

. git-sh-setup || die "Not a git archive"

LF='
'

usage () {
    die "git-merge [-n] [-s <strategy>]... <merge-message> <head> <remote>+"
}

# all_strategies='resolve fredrik stupid octopus'

all_strategies='fredrik octopus resolve stupid'
default_strategies='resolve octopus'
use_strategies=

dropheads() {
	rm -f -- "$GIT_DIR/MERGE_HEAD" || exit 1
}

summary() {
	case "$no_summary" in
	'')
		git-diff-tree -p -M $head "$1" |
		git-apply --stat --summary
		;;
	esac
}

while case "$#" in 0) break ;; esac
do
	case "$1" in
	-n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
		--no-summa|--no-summar|--no-summary)
		no_summary=t ;;
	-s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
		--strateg=*|--strategy=*|\
	-s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
		case "$#,$1" in
		*,*=*)
			strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
		0,*)
			usage ;;
		*)
			strategy="$2"
			shift ;;
		esac
		case " $all_strategies " in
		*" $strategy "*)
			use_strategies="$use_strategies$strategy " ;;
		*)
			die "available strategies are: $all_strategies" ;;
		esac
		;;
	-*)	usage ;;
	*)	break ;;
	esac
	shift
done

case "$use_strategies" in
'')
	use_strategies=$default_strategies
	;;
esac
test "$#" -le 2 && usage ;# we need at least two heads.

merge_msg="$1"
shift
head=$(git-rev-parse --verify "$1"^0) || usage
shift

# All the rest are remote heads
for remote
do
	git-rev-parse --verify "$remote"^0 >/dev/null ||
	    die "$remote - not something we can merge"
done

common=$(git-show-branch --merge-base $head "$@")
echo "$head" >"$GIT_DIR/ORIG_HEAD"

case "$#,$common" in
*,'')
	die "Unable to find common commit between $head and $*"
	;;
1,"$1")
	# If head can reach all the merge then we are up to date.
	# but first the most common case of merging one remote
	echo "Already up-to-date. Yeeah!"
	dropheads
	exit 0
	;;
1,"$head")
	# Again the most common case of merging one remote.
	echo "Updating from $head to $1."
	git-update-index --refresh 2>/dev/null
	git-read-tree -u -m $head "$1" || exit 1
	git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD"
	summary "$1"
	dropheads
	exit 0
	;;
1,*)
	# We are not doing octopus and not fast forward.  Need a
	# real merge.
	;;
*)
	# An octopus.  If we can reach all the remote we are up to date.
	up_to_date=t
	for remote
	do
		common_one=$(git-merge-base $head $remote)
		if test "$common_one" != "$remote"
		then
			up_to_date=f
			break
		fi
	done
	if test "$up_to_date" = t
	then
		echo "Already up-to-date. Yeeah!"
		dropheads
		exit 0
	fi
	;;
esac

# At this point we need a real merge.  Require that the tree matches
# exactly our head.

git-update-index --refresh &&
test '' = "`git-diff-index --cached --name-only $head`" || {
	die "Need real merge but the working tree has local changes."
}

result_tree= best_cnt=-1 best_strategy= wt_strategy=
for strategy in $use_strategies
do
    test "$wt_strategy" = '' || {
	echo "Rewinding the tree to pristine..."
	git reset --hard $head
    }
    echo "Trying merge strategy $strategy..."
    wt_strategy=$strategy
    git-merge-$strategy $common -- $head "$@" || {

	# The backend exits with 1 when conflicts are left to be resolved,
	# with 2 when it does not handle the given merge at all.

	exit=$?
	if test "$exit" -eq 1
	then
	    cnt=`{
		git-diff-files --name-only
		git-ls-files --unmerged
	    } | wc -l`
	    if test $best_cnt -le 0 -o $cnt -le $best_cnt
	    then
		best_strategy=$strategy
		best_cnt=$cnt
	    fi
	fi
	continue
    }

    # Automerge succeeded.
    result_tree=$(git-write-tree) && break
done

# If we have a resulting tree, that means the strategy module
# auto resolved the merge cleanly.
if test '' != "$result_tree"
then
    parents="-p $head"
    for remote
    do
        parents="$parents -p $remote"
    done
    result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents)
    echo "Committed merge $result_commit, made by $wt_strategy."
    echo $result_commit >"$GIT_DIR/HEAD"
    summary $result_commit
    dropheads
    exit 0
fi

# Pick the result from the best strategy and have the user fix it up.
case "$best_strategy" in
'')
	git reset --hard $head
	die "No merge strategy handled the merge."
	;;
"$wt_strategy")
	# We already have its result in the working tree.
	;;
*)
	echo "Rewinding the tree to pristine..."
	git reset --hard $head
	echo "Using the $best_strategy to prepare resolving by hand."
	git-merge-$best_strategy $common -- $head "$@"
	;;
esac
for remote
do
	echo $remote
done >"$GIT_DIR/MERGE_HEAD"
die "Automatic merge failed; fix up by hand"
Commit	Line	Data
91063bbc JH	1	#!/bin/sh
	2	#
	3	# Copyright (c) 2005 Junio C Hamano
	4	#
	5
	6	. git-sh-setup \|\| die "Not a git archive"
	7
	8	LF='
	9	'
	10
	11	usage () {
	12	die "git-merge [-n] [-s <strategy>]... <merge-message> <head> <remote>+"
	13	}
	14
2276aa6c	15	# all_strategies='resolve fredrik stupid octopus'
91063bbc	16
720d150c	17	all_strategies='fredrik octopus resolve stupid'
2276aa6c	18	default_strategies='resolve octopus'
91063bbc JH	19	use_strategies=
	20
	21	dropheads() {
	22	rm -f -- "$GIT_DIR/MERGE_HEAD" \|\| exit 1
	23	}
	24
	25	summary() {
	26	case "$no_summary" in
	27	'')
	28	git-diff-tree -p -M $head "$1" \|
	29	git-apply --stat --summary
	30	;;
	31	esac
	32	}
	33
	34	while case "$#" in 0) break ;; esac
	35	do
	36	case "$1" in
	37	-n\|--n\|--no\|--no-\|--no-s\|--no-su\|--no-sum\|--no-summ\|\
	38	--no-summa\|--no-summar\|--no-summary)
	39	no_summary=t ;;
	40	-s=\|--s=\|--st=\|--str=\|--stra=\|--strat=\|--strate=*\|\
	41	--strateg=\|--strategy=\|\
	42	-s\|--s\|--st\|--str\|--stra\|--strat\|--strate\|--strateg\|--strategy)
	43	case "$#,$1" in
	44	,=*)
	45	strategy=`expr "$1" : '-[^=]=\(.\)'` ;;
	46	0,*)
	47	usage ;;
	48	*)
	49	strategy="$2"
	50	shift ;;
	51	esac
	52	case " $all_strategies " in
	53	" $strategy ")
	54	use_strategies="$use_strategies$strategy " ;;
	55	*)
	56	die "available strategies are: $all_strategies" ;;
	57	esac
	58	;;
	59	-*) usage ;;
	60	*) break ;;
	61	esac
	62	shift
	63	done
	64
	65	case "$use_strategies" in
	66	'')
	67	use_strategies=$default_strategies
	68	;;
	69	esac
	70	test "$#" -le 2 && usage ;# we need at least two heads.
	71
	72	merge_msg="$1"
	73	shift
	74	head=$(git-rev-parse --verify "$1"^0) \|\| usage
	75	shift
	76
	77	# All the rest are remote heads
	78	for remote
	79	do
	80	git-rev-parse --verify "$remote"^0 >/dev/null \|\|
	81	die "$remote - not something we can merge"
	82	done
83
84	common=$(git-show-branch --merge-base $head "$@")
85	echo "$head" >"$GIT_DIR/ORIG_HEAD"
86
87	case "$#,$common" in
88	*,'')
89	die "Unable to find common commit between $head and $*"
90	;;
91	1,"$1")
92	# If head can reach all the merge then we are up to date.
93	# but first the most common case of merging one remote
94	echo "Already up-to-date. Yeeah!"
95	dropheads
96	exit 0
97	;;
98	1,"$head")
99	# Again the most common case of merging one remote.
100	echo "Updating from $head to $1."
101	git-update-index --refresh 2>/dev/null
102	git-read-tree -u -m $head "$1" \|\| exit 1
103	git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD"
104	summary "$1"
105	dropheads
106	exit 0
107	;;
108	1,*)
109	# We are not doing octopus and not fast forward. Need a
110	# real merge.
111	;;
112	*)
113	# An octopus. If we can reach all the remote we are up to date.
114	up_to_date=t
115	for remote
116	do
117	common_one=$(git-merge-base $head $remote)
118	if test "$common_one" != "$remote"
119	then
120	up_to_date=f
121	break
122	fi
123	done
124	if test "$up_to_date" = t
125	then
126	echo "Already up-to-date. Yeeah!"
127	dropheads
128	exit 0
129	fi
130	;;
131	esac
132
133	# At this point we need a real merge. Require that the tree matches
134	# exactly our head.
135
136	git-update-index --refresh &&
137	test '' = "`git-diff-index --cached --name-only $head`" \|\| {
138	die "Need real merge but the working tree has local changes."
139	}
140
141	result_tree= best_cnt=-1 best_strategy= wt_strategy=
142	for strategy in $use_strategies
143	do
144	test "$wt_strategy" = '' \|\| {
145	echo "Rewinding the tree to pristine..."
146	git reset --hard $head
147	}
148	echo "Trying merge strategy $strategy..."
149	wt_strategy=$strategy
150	git-merge-$strategy $common -- $head "$@" \|\| {
151
152	# The backend exits with 1 when conflicts are left to be resolved,
153	# with 2 when it does not handle the given merge at all.
154
155	exit=$?
156	if test "$exit" -eq 1
157	then
158	cnt=`{
159	git-diff-files --name-only
160	git-ls-files --unmerged
161	} \| wc -l`
162	if test $best_cnt -le 0 -o $cnt -le $best_cnt
163	then
164	best_strategy=$strategy
165	best_cnt=$cnt
166	fi
167	fi
168	continue
169	}
170
171	# Automerge succeeded.
172	result_tree=$(git-write-tree) && break
173	done
174
175	# If we have a resulting tree, that means the strategy module
176	# auto resolved the merge cleanly.
177	if test '' != "$result_tree"
178	then
179	parents="-p $head"
180	for remote
181	do
182	parents="$parents -p $remote"
183	done
184	result_commit=$(echo "$merge_msg" \| git-commit-tree $result_tree $parents)
185	echo "Committed merge $result_commit, made by $wt_strategy."
186	echo $result_commit >"$GIT_DIR/HEAD"
187	summary $result_commit
188	dropheads
189	exit 0
190	fi
191
192	# Pick the result from the best strategy and have the user fix it up.
193	case "$best_strategy" in
194	'')
195	git reset --hard $head
196	die "No merge strategy handled the merge."
197	;;
198	"$wt_strategy")
199	# We already have its result in the working tree.
200	;;
201	*)
202	echo "Rewinding the tree to pristine..."
203	git reset --hard $head
204	echo "Using the $best_strategy to prepare resolving by hand."
205	git-merge-$best_strategy $common -- $head "$@"
206	;;
207	esac
208	for remote
209	do
210	echo $remote
211	done >"$GIT_DIR/MERGE_HEAD"
212	die "Automatic merge failed; fix up by hand"