[thirdparty/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 recursive stupid octopus'

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

dropsave() {
	rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
		 "$GIT_DIR/MERGE_SAVE" || exit 1
}

savestate() {
	git diff -r -z --name-only $head | cpio -0 -o >"$GIR_DIR/MERGE_SAVE"
}

restorestate() {
        if test -f "$GIT_DIR/MERGE_SAVE"
	then
		git reset --hard $head
		cpio -iuv <"$GIT_DIR/MERGE_SAVE"
		git-update-index --refresh >/dev/null
	fi
}

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" : '-[^=]*=\(.*\)'` ;;
		1,*)
			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_arg="$1"
head=$(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_arg and $*"
	;;
1,"$1")
	# If head can reach all the merge then we are up to date.
	# but first the most common case of merging one remote
	echo "Already up-to-date. Yeeah!"
	dropsave
	exit 0
	;;
1,"$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 "$1"
	dropsave
	exit 0
	;;
1,*)
	# We are not doing octopus and not fast forward.  Need a
	# real merge.
	;;
*)
	# An octopus.  If we can reach all the remote we are up to date.
	up_to_date=t
	for remote
	do
		common_one=$(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!"
		dropsave
		exit 0
	fi
	;;
esac

# At this point, we need a real merge.  No matter what strategy
# we use, it would operate on the index, possibly affecting the
# working tree, and when resolved cleanly, have the desired tree
# in the index -- this means that the index must be in sync with
# the $head commit.
files=$(git-diff-index --cached --name-only $head) || exit
if [ "$files" ]; then
   echo >&2 "Dirty index: cannot merge (dirty: $files)"
   exit 1
fi

case "$use_strategies" in
?*' '?*)
    # Stash away the local changes so that we can try more than one.
    savestate
    single_strategy=no
    ;;
*)
    rm -f "$GIT_DIR/MERGE_SAVE"
    single_strategy=yes
    ;;
esac

result_tree= best_cnt=-1 best_strategy= wt_strategy=
for strategy in $use_strategies
do
    test "$wt_strategy" = '' || {
	echo "Rewinding the tree to pristine..."
	restorestate
    }
    case "$single_strategy" in
    no)
	echo "Trying merge strategy $strategy..."
	;;
    esac

    # Remember which strategy left the state in the working tree
    wt_strategy=$strategy

    git-merge-$strategy $common -- "$head_arg" "$@" || {

	# 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
    dropsave
    exit 0
fi

# Pick the result from the best strategy and have the user fix it up.
case "$best_strategy" in
'')
	restorestate
	die "No merge strategy handled the merge."
	;;
"$wt_strategy")
	# We already have its result in the working tree.
	;;
*)
	echo "Rewinding the tree to pristine..."
	restorestate
	echo "Using the $best_strategy to prepare resolving by hand."
	git-merge-$best_strategy $common -- "$head_arg" "$@"
	;;
esac
for remote
do
	echo $remote
done >"$GIT_DIR/MERGE_HEAD"
echo $merge_msg >"$GIT_DIR/MERGE_MSG"

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
e4cf17ce	15	# all_strategies='resolve recursive stupid octopus'
91063bbc	16
e4cf17ce	17	all_strategies='recursive octopus resolve stupid'
2276aa6c	18	default_strategies='resolve octopus'
91063bbc JH	19	use_strategies=
91063bbc JH	20
a9358240	21	dropsave() {
deca7e8c	22	rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
a9358240 JH	23	"$GIT_DIR/MERGE_SAVE" \|\| exit 1
	24	}
	25
	26	savestate() {
	27	git diff -r -z --name-only $head \| cpio -0 -o >"$GIR_DIR/MERGE_SAVE"
	28	}
	29
	30	restorestate() {
deca7e8c JH	31	if test -f "$GIT_DIR/MERGE_SAVE"
	32	then
	33	git reset --hard $head
	34	cpio -iuv <"$GIT_DIR/MERGE_SAVE"
	35	git-update-index --refresh >/dev/null
	36	fi
91063bbc JH	37	}
	38
	39	summary() {
	40	case "$no_summary" in
	41	'')
	42	git-diff-tree -p -M $head "$1" \|
	43	git-apply --stat --summary
	44	;;
	45	esac
	46	}
	47
	48	while case "$#" in 0) break ;; esac
	49	do
	50	case "$1" in
	51	-n\|--n\|--no\|--no-\|--no-s\|--no-su\|--no-sum\|--no-summ\|\
	52	--no-summa\|--no-summar\|--no-summary)
	53	no_summary=t ;;
	54	-s=\|--s=\|--st=\|--str=\|--stra=\|--strat=\|--strate=*\|\
	55	--strateg=\|--strategy=\|\
	56	-s\|--s\|--st\|--str\|--stra\|--strat\|--strate\|--strateg\|--strategy)
	57	case "$#,$1" in
	58	,=*)
	59	strategy=`expr "$1" : '-[^=]=\(.\)'` ;;
f88ed172	60	1,*)
91063bbc JH	61	usage ;;
	62	*)
	63	strategy="$2"
	64	shift ;;
	65	esac
	66	case " $all_strategies " in
	67	" $strategy ")
	68	use_strategies="$use_strategies$strategy " ;;
	69	*)
	70	die "available strategies are: $all_strategies" ;;
	71	esac
	72	;;
	73	-*) usage ;;
	74	*) break ;;
	75	esac
	76	shift
	77	done
	78
	79	case "$use_strategies" in
	80	'')
	81	use_strategies=$default_strategies
	82	;;
	83	esac
	84	test "$#" -le 2 && usage ;# we need at least two heads.
	85
	86	merge_msg="$1"
	87	shift
8cc01e50	88	head_arg="$1"
91063bbc JH	89	head=$(git-rev-parse --verify "$1"^0) \|\| usage
	90	shift
	91
	92	# All the rest are remote heads
	93	for remote
	94	do
	95	git-rev-parse --verify "$remote"^0 >/dev/null \|\|
	96	die "$remote - not something we can merge"
	97	done
	98
	99	common=$(git-show-branch --merge-base $head "$@")
	100	echo "$head" >"$GIT_DIR/ORIG_HEAD"
	101
	102	case "$#,$common" in
	103	*,'')
8cc01e50	104	die "Unable to find common commit between $head_arg and $*"
91063bbc JH	105	;;
	106	1,"$1")
	107	# If head can reach all the merge then we are up to date.
	108	# but first the most common case of merging one remote
	109	echo "Already up-to-date. Yeeah!"
a9358240	110	dropsave
91063bbc JH	111	exit 0
	112	;;
	113	1,"$head")
	114	# Again the most common case of merging one remote.
	115	echo "Updating from $head to $1."
	116	git-update-index --refresh 2>/dev/null
	117	git-read-tree -u -m $head "$1" \|\| exit 1
	118	git-rev-parse --verify "$1^0" > "$GIT_DIR/HEAD"
	119	summary "$1"
a9358240	120	dropsave
91063bbc JH	121	exit 0
	122	;;
	123	1,*)
	124	# We are not doing octopus and not fast forward. Need a
	125	# real merge.
	126	;;
	127	*)
	128	# An octopus. If we can reach all the remote we are up to date.
	129	up_to_date=t
	130	for remote
	131	do
	132	common_one=$(git-merge-base $head $remote)
	133	if test "$common_one" != "$remote"
	134	then
	135	up_to_date=f
	136	break
	137	fi
	138	done
	139	if test "$up_to_date" = t
	140	then
	141	echo "Already up-to-date. Yeeah!"
a9358240	142	dropsave
91063bbc JH	143	exit 0
	144	fi
	145	;;
	146	esac
	147
a9358240 JH	148	# At this point, we need a real merge. No matter what strategy
	149	# we use, it would operate on the index, possibly affecting the
	150	# working tree, and when resolved cleanly, have the desired tree
	151	# in the index -- this means that the index must be in sync with
	152	# the $head commit.
	153	files=$(git-diff-index --cached --name-only $head) \|\| exit
	154	if [ "$files" ]; then
	155	echo >&2 "Dirty index: cannot merge (dirty: $files)"
	156	exit 1
	157	fi
91063bbc	158
a9358240 JH	159	case "$use_strategies" in
	160	?' '?)
	161	# Stash away the local changes so that we can try more than one.
	162	savestate
	163	single_strategy=no
	164	;;
	165	*)
deca7e8c	166	rm -f "$GIT_DIR/MERGE_SAVE"
a9358240 JH	167	single_strategy=yes
	168	;;
	169	esac
91063bbc JH	170
	171	result_tree= best_cnt=-1 best_strategy= wt_strategy=
	172	for strategy in $use_strategies
	173	do
	174	test "$wt_strategy" = '' \|\| {
	175	echo "Rewinding the tree to pristine..."
a9358240	176	restorestate
91063bbc	177	}
a9358240 JH	178	case "$single_strategy" in
	179	no)
	180	echo "Trying merge strategy $strategy..."
	181	;;
	182	esac
	183
	184	# Remember which strategy left the state in the working tree
91063bbc	185	wt_strategy=$strategy
a9358240 JH	186
a9358240 JH	187	git-merge-$strategy $common -- "$head_arg" "$@" \|\| {
91063bbc JH	188
	189	# The backend exits with 1 when conflicts are left to be resolved,
	190	# with 2 when it does not handle the given merge at all.
	191
	192	exit=$?
	193	if test "$exit" -eq 1
	194	then
	195	cnt=`{
	196	git-diff-files --name-only
	197	git-ls-files --unmerged
	198	} \| wc -l`
	199	if test $best_cnt -le 0 -o $cnt -le $best_cnt
	200	then
	201	best_strategy=$strategy
	202	best_cnt=$cnt
	203	fi
	204	fi
	205	continue
	206	}
	207
	208	# Automerge succeeded.
	209	result_tree=$(git-write-tree) && break
	210	done
	211
	212	# If we have a resulting tree, that means the strategy module
	213	# auto resolved the merge cleanly.
	214	if test '' != "$result_tree"
	215	then
	216	parents="-p $head"
	217	for remote
	218	do
	219	parents="$parents -p $remote"
	220	done
	221	result_commit=$(echo "$merge_msg" \| git-commit-tree $result_tree $parents)
	222	echo "Committed merge $result_commit, made by $wt_strategy."
	223	echo $result_commit >"$GIT_DIR/HEAD"
	224	summary $result_commit
a9358240	225	dropsave
91063bbc JH	226	exit 0
	227	fi
	228
	229	# Pick the result from the best strategy and have the user fix it up.
	230	case "$best_strategy" in
	231	'')
a9358240	232	restorestate
91063bbc JH	233	die "No merge strategy handled the merge."
	234	;;
	235	"$wt_strategy")
	236	# We already have its result in the working tree.
	237	;;
	238	*)
	239	echo "Rewinding the tree to pristine..."
a9358240	240	restorestate
91063bbc	241	echo "Using the $best_strategy to prepare resolving by hand."
a9358240	242	git-merge-$best_strategy $common -- "$head_arg" "$@"
91063bbc JH	243	;;
	244	esac
	245	for remote
	246	do
	247	echo $remote
	248	done >"$GIT_DIR/MERGE_HEAD"
deca7e8c JH	249	echo $merge_msg >"$GIT_DIR/MERGE_MSG"
deca7e8c JH	250
91063bbc	251	die "Automatic merge failed; fix up by hand"