git-merge.sh - git - Git at Google

 #!/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=

 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" : '-[^=]*=\(.*\)'` ;;
 		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="$1"
 shift
 head=$(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"
	#!/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=

	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" : '-[^=]=\(.\)'` ;;
	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="$1"
	shift
	head=$(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"