Merge branch 'da/difftool-mergtool-refactor'

* da/difftool-mergtool-refactor:
  mergetools/meld: Use '--output' when available
  mergetool--lib: Refactor tools into separate files
  mergetool--lib: Make style consistent with git
  difftool--helper: Make style consistent with git

Makefile

@@ -302,6 +302,7 @@ bindir = $(prefix)/$(bindir_relative)
 mandir = share/man
 infodir = share/info
 gitexecdir = libexec/git-core
+mergetoolsdir = $(gitexecdir)/mergetools
 sharedir = $(prefix)/share
 gitwebdir = $(sharedir)/gitweb
 template_dir = share/git-core/templates
@@ -2258,6 +2259,13 @@ endif
 gitexec_instdir_SQ = $(subst ','\'',$(gitexec_instdir))
 export gitexec_instdir
 
+ifneq ($(filter /%,$(firstword $(mergetoolsdir))),)
+mergetools_instdir = $(mergetoolsdir)
+else
+mergetools_instdir = $(prefix)/$(mergetoolsdir)
+endif
+mergetools_instdir_SQ = $(subst ','\'',$(mergetools_instdir))
+
 install_bindir_programs := $(patsubst %,%$X,$(BINDIR_PROGRAMS_NEED_X)) $(BINDIR_PROGRAMS_NO_X)
 
 install: all
@@ -2267,6 +2275,9 @@ install: all
 	$(INSTALL) -m 644 $(SCRIPT_LIB) '$(DESTDIR_SQ)$(gitexec_instdir_SQ)'
 	$(INSTALL) $(install_bindir_programs) '$(DESTDIR_SQ)$(bindir_SQ)'
 	$(MAKE) -C templates DESTDIR='$(DESTDIR_SQ)' install
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(mergetools_instdir_SQ)'
+	(cd mergetools && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)$(mergetools_instdir_SQ)' && umask 022 && $(TAR) xof -)
 ifndef NO_PERL
 	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
 	$(MAKE) -C gitweb install

git-difftool--helper.sh

@@ -13,7 +13,8 @@ TOOL_MODE=diff
 should_prompt () {
 	prompt_merge=$(git config --bool mergetool.prompt || echo true)
 	prompt=$(git config --bool difftool.prompt || echo $prompt_merge)
-	if test "$prompt" = true; then
+	if test "$prompt" = true
+	then
 		test -z "$GIT_DIFFTOOL_NO_PROMPT"
 	else
 		test -n "$GIT_DIFFTOOL_PROMPT"
@@ -37,9 +38,11 @@ launch_merge_tool () {
 
 	# $LOCAL and $REMOTE are temporary files so prompt
 	# the user with the real $MERGED name before launching $merge_tool.
-	if should_prompt; then
+	if should_prompt
+	then
 		printf "\nViewing: '$MERGED'\n"
-		if use_ext_cmd; then
+		if use_ext_cmd
+		then
 			printf "Hit return to launch '%s': " \
 				"$GIT_DIFFTOOL_EXTCMD"
 		else
@@ -48,7 +51,8 @@ launch_merge_tool () {
 		read ans
 	fi
 
-	if use_ext_cmd; then
+	if use_ext_cmd
+	then
 		export BASE
 		eval $GIT_DIFFTOOL_EXTCMD '"$LOCAL"' '"$REMOTE"'
 	else
@@ -56,8 +60,10 @@ launch_merge_tool () {
 	fi
 }
 
-if ! use_ext_cmd; then
-	if test -n "$GIT_DIFF_TOOL"; then
+if ! use_ext_cmd
+then
+	if test -n "$GIT_DIFF_TOOL"
+	then
 		merge_tool="$GIT_DIFF_TOOL"
 	else
 		merge_tool="$(get_merge_tool)" || exit

git-mergetool--lib.sh

@@ -9,33 +9,16 @@ merge_mode() {
 }
 
 translate_merge_tool_path () {
-	case "$1" in
-	araxis)
-		echo compare
-		;;
-	bc3)
-		echo bcompare
-		;;
-	emerge)
-		echo emacs
-		;;
-	gvimdiff|gvimdiff2)
-		echo gvim
-		;;
-	vimdiff|vimdiff2)
-		echo vim
-		;;
-	*)
-		echo "$1"
-		;;
-	esac
+	echo "$1"
 }
 
 check_unchanged () {
-	if test "$MERGED" -nt "$BACKUP"; then
+	if test "$MERGED" -nt "$BACKUP"
+	then
 		status=0
 	else
-		while true; do
+		while true
+		do
 			echo "$MERGED seems unchanged."
 			printf "Was the merge successful? [y/n] "
 			read answer
@@ -47,37 +30,57 @@ check_unchanged () {
 	fi
 }
 
+valid_tool_config () {
+	if test -n "$(get_merge_tool_cmd "$1")"
+	then
+		return 0
+	else
+		return 1
+	fi
+}
+
 valid_tool () {
+	setup_tool "$1" || valid_tool_config "$1"
+}
+
+setup_tool () {
 	case "$1" in
-	araxis | bc3 | diffuse | ecmerge | emerge | gvimdiff | gvimdiff2 | \
-	kdiff3 | meld | opendiff | p4merge | tkdiff | vimdiff | vimdiff2 | xxdiff)
-		;; # happy
-	kompare)
-		if ! diff_mode; then
-			return 1
-		fi
-		;;
-	tortoisemerge)
-		if ! merge_mode; then
-			return 1
-		fi
+	vim*|gvim*)
+		tool=vim
 		;;
 	*)
-		if test -z "$(get_merge_tool_cmd "$1")"; then
-			return 1
-		fi
+		tool="$1"
 		;;
 	esac
+	mergetools="$(git --exec-path)/mergetools"
+
+	# Load the default definitions
+	. "$mergetools/defaults"
+	if ! test -f "$mergetools/$tool"
+	then
+		return 1
+	fi
+
+	# Load the redefined functions
+	. "$mergetools/$tool"
+
+	if merge_mode && ! can_merge
+	then
+		echo "error: '$tool' can not be used to resolve merges" >&2
+		exit 1
+	elif diff_mode && ! can_diff
+	then
+		echo "error: '$tool' can only be used to resolve merges" >&2
+		exit 1
+	fi
+	return 0
 }
 
 get_merge_tool_cmd () {
 	# Prints the custom command for a merge tool
-	if test -n "$1"; then
-		merge_tool="$1"
-	else
-		merge_tool="$(get_merge_tool)"
-	fi
-	if diff_mode; then
+	merge_tool="$1"
+	if diff_mode
+	then
 		echo "$(git config difftool.$merge_tool.cmd ||
 			git config mergetool.$merge_tool.cmd)"
 	else
@@ -85,6 +88,7 @@ get_merge_tool_cmd () {
 	fi
 }
 
+# Entry point for running tools
 run_merge_tool () {
 	# If GIT_PREFIX is empty then we cannot use it in tools
 	# that expect to be able to chdir() to its value.
@@ -95,271 +99,29 @@ run_merge_tool () {
 	base_present="$2"
 	status=0
 
-	case "$1" in
-	araxis)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" -wait -merge -3 -a1 \
-					"$BASE" "$LOCAL" "$REMOTE" "$MERGED" \
-					>/dev/null 2>&1
-			else
-				"$merge_tool_path" -wait -2 \
-					"$LOCAL" "$REMOTE" "$MERGED" \
-					>/dev/null 2>&1
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" -wait -2 "$LOCAL" "$REMOTE" \
-				>/dev/null 2>&1
-		fi
-		;;
-	bc3)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" "$LOCAL" "$REMOTE" "$BASE" \
-					-mergeoutput="$MERGED"
-			else
-				"$merge_tool_path" "$LOCAL" "$REMOTE" \
-					-mergeoutput="$MERGED"
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE"
-		fi
-		;;
-	diffuse)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" \
-					"$LOCAL" "$MERGED" "$REMOTE" \
-					"$BASE" | cat
-			else
-				"$merge_tool_path" \
-					"$LOCAL" "$MERGED" "$REMOTE" | cat
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
-		fi
-		;;
-	ecmerge)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" \
-					--default --mode=merge3 --to="$MERGED"
-			else
-				"$merge_tool_path" "$LOCAL" "$REMOTE" \
-					--default --mode=merge2 --to="$MERGED"
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" --default --mode=diff2 \
-				"$LOCAL" "$REMOTE"
-		fi
-		;;
-	emerge)
-		if merge_mode; then
-			if $base_present; then
-				"$merge_tool_path" \
-					-f emerge-files-with-ancestor-command \
-					"$LOCAL" "$REMOTE" "$BASE" \
-					"$(basename "$MERGED")"
-			else
-				"$merge_tool_path" \
-					-f emerge-files-command \
-					"$LOCAL" "$REMOTE" \
-					"$(basename "$MERGED")"
-			fi
-			status=$?
-		else
-			"$merge_tool_path" -f emerge-files-command \
-				"$LOCAL" "$REMOTE"
-		fi
-		;;
-	gvimdiff|vimdiff)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" -f -d -c "wincmd J" \
-					"$MERGED" "$LOCAL" "$BASE" "$REMOTE"
-			else
-				"$merge_tool_path" -f -d -c "wincmd l" \
-					"$LOCAL" "$MERGED" "$REMOTE"
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" -R -f -d -c "wincmd l" \
-				-c 'cd $GIT_PREFIX' \
-				"$LOCAL" "$REMOTE"
-		fi
-		;;
-	gvimdiff2|vimdiff2)
-		if merge_mode; then
-			touch "$BACKUP"
-			"$merge_tool_path" -f -d -c "wincmd l" \
-				"$LOCAL" "$MERGED" "$REMOTE"
-			check_unchanged
-		else
-			"$merge_tool_path" -R -f -d -c "wincmd l" \
-				-c 'cd $GIT_PREFIX' \
-				"$LOCAL" "$REMOTE"
-		fi
-		;;
-	kdiff3)
-		if merge_mode; then
-			if $base_present; then
-				("$merge_tool_path" --auto \
-					--L1 "$MERGED (Base)" \
-					--L2 "$MERGED (Local)" \
-					--L3 "$MERGED (Remote)" \
-					-o "$MERGED" \
-					"$BASE" "$LOCAL" "$REMOTE" \
-				> /dev/null 2>&1)
-			else
-				("$merge_tool_path" --auto \
-					--L1 "$MERGED (Local)" \
-					--L2 "$MERGED (Remote)" \
-					-o "$MERGED" \
-					"$LOCAL" "$REMOTE" \
-				> /dev/null 2>&1)
-			fi
-			status=$?
-		else
-			("$merge_tool_path" --auto \
-				--L1 "$MERGED (A)" \
-				--L2 "$MERGED (B)" "$LOCAL" "$REMOTE" \
-			> /dev/null 2>&1)
-		fi
-		;;
-	kompare)
-		"$merge_tool_path" "$LOCAL" "$REMOTE"
-		;;
-	meld)
-		if merge_mode; then
-			touch "$BACKUP"
-			"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"
-			check_unchanged
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE"
-		fi
-		;;
-	opendiff)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" "$LOCAL" "$REMOTE" \
-					-ancestor "$BASE" \
-					-merge "$MERGED" | cat
-			else
-				"$merge_tool_path" "$LOCAL" "$REMOTE" \
-					-merge "$MERGED" | cat
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
-		fi
-		;;
-	p4merge)
-		if merge_mode; then
-			touch "$BACKUP"
-			$base_present || >"$BASE"
-			"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" "$MERGED"
-			check_unchanged
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE"
-		fi
-		;;
-	tkdiff)
-		if merge_mode; then
-			if $base_present; then
-				"$merge_tool_path" -a "$BASE" \
-					-o "$MERGED" "$LOCAL" "$REMOTE"
-			else
-				"$merge_tool_path" \
-					-o "$MERGED" "$LOCAL" "$REMOTE"
-			fi
-			status=$?
-		else
-			"$merge_tool_path" "$LOCAL" "$REMOTE"
-		fi
-		;;
-	tortoisemerge)
-		if $base_present; then
-			touch "$BACKUP"
-			"$merge_tool_path" \
-				-base:"$BASE" -mine:"$LOCAL" \
-				-theirs:"$REMOTE" -merged:"$MERGED"
-			check_unchanged
-		else
-			echo "TortoiseMerge cannot be used without a base" 1>&2
-			status=1
-		fi
-		;;
-	xxdiff)
-		if merge_mode; then
-			touch "$BACKUP"
-			if $base_present; then
-				"$merge_tool_path" -X --show-merged-pane \
-					-R 'Accel.SaveAsMerged: "Ctrl-S"' \
-					-R 'Accel.Search: "Ctrl+F"' \
-					-R 'Accel.SearchForward: "Ctrl-G"' \
-					--merged-file "$MERGED" \
-					"$LOCAL" "$BASE" "$REMOTE"
-			else
-				"$merge_tool_path" -X $extra \
-					-R 'Accel.SaveAsMerged: "Ctrl-S"' \
-					-R 'Accel.Search: "Ctrl+F"' \
-					-R 'Accel.SearchForward: "Ctrl-G"' \
-					--merged-file "$MERGED" \
-					"$LOCAL" "$REMOTE"
-			fi
-			check_unchanged
-		else
-			"$merge_tool_path" \
-				-R 'Accel.Search: "Ctrl+F"' \
-				-R 'Accel.SearchForward: "Ctrl-G"' \
-				"$LOCAL" "$REMOTE"
-		fi
-		;;
-	*)
-		merge_tool_cmd="$(get_merge_tool_cmd "$1")"
-		if test -z "$merge_tool_cmd"; then
-			if merge_mode; then
-				status=1
-			fi
-			break
-		fi
-		if merge_mode; then
-			trust_exit_code="$(git config --bool \
-				mergetool."$1".trustExitCode || echo false)"
-			if test "$trust_exit_code" = "false"; then
-				touch "$BACKUP"
-				( eval $merge_tool_cmd )
-				check_unchanged
-			else
-				( eval $merge_tool_cmd )
-				status=$?
-			fi
-		else
-			( eval $merge_tool_cmd )
-		fi
-		;;
-	esac
+	# Bring tool-specific functions into scope
+	setup_tool "$1"
+
+	if merge_mode
+	then
+		merge_cmd "$1"
+	else
+		diff_cmd "$1"
+	fi
 	return $status
 }
 
 guess_merge_tool () {
-	if merge_mode; then
+	if merge_mode
+	then
 		tools="tortoisemerge"
 	else
 		tools="kompare"
 	fi
-	if test -n "$DISPLAY"; then
-		if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
+	if test -n "$DISPLAY"
+	then
+		if test -n "$GNOME_DESKTOP_SESSION_ID"
+		then
 			tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
 		else
 			tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
@@ -380,7 +142,8 @@ guess_merge_tool () {
 	for i in $tools
 	do
 		merge_tool_path="$(translate_merge_tool_path "$i")"
-		if type "$merge_tool_path" > /dev/null 2>&1; then
+		if type "$merge_tool_path" >/dev/null 2>&1
+		then
 			echo "$i"
 			return 0
 		fi
@@ -393,12 +156,14 @@ guess_merge_tool () {
 get_configured_merge_tool () {
 	# Diff mode first tries diff.tool and falls back to merge.tool.
 	# Merge mode only checks merge.tool
-	if diff_mode; then
+	if diff_mode
+	then
 		merge_tool=$(git config diff.tool || git config merge.tool)
 	else
 		merge_tool=$(git config merge.tool)
 	fi
-	if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
+	if test -n "$merge_tool" && ! valid_tool "$merge_tool"
+	then
 		echo >&2 "git config option $TOOL_MODE.tool set to unknown tool: $merge_tool"
 		echo >&2 "Resetting to default..."
 		return 1
@@ -408,26 +173,26 @@ get_configured_merge_tool () {
 
 get_merge_tool_path () {
 	# A merge tool has been set, so verify that it's valid.
-	if test -n "$1"; then
-		merge_tool="$1"
-	else
-		merge_tool="$(get_merge_tool)"
-	fi
-	if ! valid_tool "$merge_tool"; then
+	merge_tool="$1"
+	if ! valid_tool "$merge_tool"
+	then
 		echo >&2 "Unknown merge tool $merge_tool"
 		exit 1
 	fi
-	if diff_mode; then
+	if diff_mode
+	then
 		merge_tool_path=$(git config difftool."$merge_tool".path ||
 				  git config mergetool."$merge_tool".path)
 	else
 		merge_tool_path=$(git config mergetool."$merge_tool".path)
 	fi
-	if test -z "$merge_tool_path"; then
+	if test -z "$merge_tool_path"
+	then
 		merge_tool_path="$(translate_merge_tool_path "$merge_tool")"
 	fi
 	if test -z "$(get_merge_tool_cmd "$merge_tool")" &&
-	! type "$merge_tool_path" > /dev/null 2>&1; then
+		! type "$merge_tool_path" >/dev/null 2>&1
+	then
 		echo >&2 "The $TOOL_MODE tool $merge_tool is not available as"\
 			 "'$merge_tool_path'"
 		exit 1
@@ -437,9 +202,10 @@ get_merge_tool_path () {
 
 get_merge_tool () {
 	# Check if a merge tool has been configured
-	merge_tool=$(get_configured_merge_tool)
+	merge_tool="$(get_configured_merge_tool)"
 	# Try to guess an appropriate merge tool if no tool has been set.
-	if test -z "$merge_tool"; then
+	if test -z "$merge_tool"
+	then
 		merge_tool="$(guess_merge_tool)" || exit
 	fi
 	echo "$merge_tool"

mergetools/araxis

@@ -0,0 +1,20 @@
+diff_cmd () {
+	"$merge_tool_path" -wait -2 "$LOCAL" "$REMOTE" >/dev/null 2>&1
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" -wait -merge -3 -a1 \
+			"$BASE" "$LOCAL" "$REMOTE" "$MERGED" >/dev/null 2>&1
+	else
+		"$merge_tool_path" -wait -2 \
+			"$LOCAL" "$REMOTE" "$MERGED" >/dev/null 2>&1
+	fi
+	check_unchanged
+}
+
+translate_merge_tool_path() {
+	echo compare
+}

mergetools/bc3

@@ -0,0 +1,20 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" "$LOCAL" "$REMOTE" "$BASE" \
+			-mergeoutput="$MERGED"
+	else
+		"$merge_tool_path" "$LOCAL" "$REMOTE" \
+			-mergeoutput="$MERGED"
+	fi
+	check_unchanged
+}
+
+translate_merge_tool_path() {
+	echo bcompare
+}

mergetools/defaults

@@ -0,0 +1,46 @@
+# Redefined by builtin tools
+can_merge () {
+	return 0
+}
+
+can_diff () {
+	return 0
+}
+
+diff_cmd () {
+	merge_tool_cmd="$(get_merge_tool_cmd "$1")"
+	if test -z "$merge_tool_cmd"
+	then
+		status=1
+		break
+	fi
+	( eval $merge_tool_cmd )
+	status=$?
+	return $status
+}
+
+merge_cmd () {
+	merge_tool_cmd="$(get_merge_tool_cmd "$1")"
+	if test -z "$merge_tool_cmd"
+	then
+		status=1
+		break
+	fi
+	trust_exit_code="$(git config --bool \
+		mergetool."$1".trustExitCode || echo false)"
+	if test "$trust_exit_code" = "false"
+	then
+		touch "$BACKUP"
+		( eval $merge_tool_cmd )
+		status=$?
+		check_unchanged
+	else
+		( eval $merge_tool_cmd )
+		status=$?
+	fi
+	return $status
+}
+
+translate_merge_tool_path () {
+	echo "$1"
+}

mergetools/diffuse

@@ -0,0 +1,17 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" \
+			"$LOCAL" "$MERGED" "$REMOTE" \
+			"$BASE" | cat
+	else
+		"$merge_tool_path" \
+			"$LOCAL" "$MERGED" "$REMOTE" | cat
+	fi
+	check_unchanged
+}

mergetools/ecmerge

@@ -0,0 +1,16 @@
+diff_cmd () {
+	"$merge_tool_path" --default --mode=diff2 "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" \
+			--default --mode=merge3 --to="$MERGED"
+	else
+		"$merge_tool_path" "$LOCAL" "$REMOTE" \
+			--default --mode=merge2 --to="$MERGED"
+	fi
+	check_unchanged
+}

mergetools/emerge

@@ -0,0 +1,23 @@
+diff_cmd () {
+	"$merge_tool_path" -f emerge-files-command "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	if $base_present
+	then
+		"$merge_tool_path" \
+			-f emerge-files-with-ancestor-command \
+			"$LOCAL" "$REMOTE" "$BASE" \
+			"$(basename "$MERGED")"
+	else
+		"$merge_tool_path" \
+			-f emerge-files-command \
+			"$LOCAL" "$REMOTE" \
+			"$(basename "$MERGED")"
+	fi
+	status=$?
+}
+
+translate_merge_tool_path() {
+	echo emacs
+}

mergetools/kdiff3

@@ -0,0 +1,24 @@
+diff_cmd () {
+	"$merge_tool_path" --auto \
+		--L1 "$MERGED (A)" --L2 "$MERGED (B)" \
+		"$LOCAL" "$REMOTE" >/dev/null 2>&1
+}
+
+merge_cmd () {
+	if $base_present
+	then
+		"$merge_tool_path" --auto \
+			--L1 "$MERGED (Base)" \
+			--L2 "$MERGED (Local)" \
+			--L3 "$MERGED (Remote)" \
+			-o "$MERGED" "$BASE" "$LOCAL" "$REMOTE" \
+		>/dev/null 2>&1
+	else
+		"$merge_tool_path" --auto \
+			--L1 "$MERGED (Local)" \
+			--L2 "$MERGED (Remote)" \
+			-o "$MERGED" "$LOCAL" "$REMOTE" \
+		>/dev/null 2>&1
+	fi
+	status=$?
+}

mergetools/kompare

@@ -0,0 +1,7 @@
+can_merge () {
+	return 1
+}
+
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}

mergetools/meld

@@ -0,0 +1,32 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	if test -z "${meld_has_output_option:+set}"
+	then
+		check_meld_for_output_version
+	fi
+	touch "$BACKUP"
+	if test "$meld_has_output_option" = true
+	then
+		"$merge_tool_path" --output "$MERGED" \
+			"$LOCAL" "$BASE" "$REMOTE"
+	else
+		"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"
+	fi
+	check_unchanged
+}
+
+# Check whether 'meld --output <file>' is supported
+check_meld_for_output_version () {
+	meld_path="$(git config mergetool.meld.path)"
+	meld_path="${meld_path:-meld}"
+
+	if "$meld_path" --output /dev/null --help >/dev/null 2>&1
+	then
+		meld_has_output_option=true
+	else
+		meld_has_output_option=false
+	fi
+}

mergetools/opendiff

@@ -0,0 +1,16 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" "$LOCAL" "$REMOTE" \
+			-ancestor "$BASE" -merge "$MERGED" | cat
+	else
+		"$merge_tool_path" "$LOCAL" "$REMOTE" \
+			-merge "$MERGED" | cat
+	fi
+	check_unchanged
+}

mergetools/p4merge

@@ -0,0 +1,10 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	$base_present || >"$BASE"
+	"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" "$MERGED"
+	check_unchanged
+}

mergetools/tkdiff

@@ -0,0 +1,12 @@
+diff_cmd () {
+	"$merge_tool_path" "$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	if $base_present
+	then
+		"$merge_tool_path" -a "$BASE" -o "$MERGED" "$LOCAL" "$REMOTE"
+	else
+		"$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
+	fi
+}

mergetools/tortoisemerge

@@ -0,0 +1,17 @@
+can_diff () {
+	return 1
+}
+
+merge_cmd () {
+	if $base_present
+	then
+		touch "$BACKUP"
+		"$merge_tool_path" \
+			-base:"$BASE" -mine:"$LOCAL" \
+			-theirs:"$REMOTE" -merged:"$MERGED"
+		check_unchanged
+	else
+		echo "TortoiseMerge cannot be used without a base" 1>&2
+		return 1
+	fi
+}

mergetools/vim

@@ -0,0 +1,44 @@
+diff_cmd () {
+	case "$1" in
+	gvimdiff|vimdiff)
+		"$merge_tool_path" -R -f -d \
+			-c 'wincmd l' -c 'cd $GIT_PREFIX' "$LOCAL" "$REMOTE"
+		;;
+	gvimdiff2|vimdiff2)
+		"$merge_tool_path" -R -f -d \
+			-c 'wincmd l' -c 'cd $GIT_PREFIX' "$LOCAL" "$REMOTE"
+		;;
+	esac
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	case "$1" in
+	gvimdiff|vimdiff)
+		if $base_present
+		then
+			"$merge_tool_path" -f -d -c 'wincmd J' \
+				"$MERGED" "$LOCAL" "$BASE" "$REMOTE"
+		else
+			"$merge_tool_path" -f -d -c 'wincmd l' \
+				"$LOCAL" "$MERGED" "$REMOTE"
+		fi
+		;;
+	gvimdiff2|vimdiff2)
+		"$merge_tool_path" -f -d -c 'wincmd l' \
+			"$LOCAL" "$MERGED" "$REMOTE"
+		;;
+	esac
+	check_unchanged
+}
+
+translate_merge_tool_path() {
+	case "$1" in
+	gvimdiff|gvimdiff2)
+		echo gvim
+		;;
+	vimdiff|vimdiff2)
+		echo vim
+		;;
+	esac
+}

mergetools/xxdiff

@@ -0,0 +1,25 @@
+diff_cmd () {
+	"$merge_tool_path" \
+		-R 'Accel.Search: "Ctrl+F"' \
+		-R 'Accel.SearchForward: "Ctrl-G"' \
+		"$LOCAL" "$REMOTE"
+}
+
+merge_cmd () {
+	touch "$BACKUP"
+	if $base_present
+	then
+		"$merge_tool_path" -X --show-merged-pane \
+			-R 'Accel.SaveAsMerged: "Ctrl-S"' \
+			-R 'Accel.Search: "Ctrl+F"' \
+			-R 'Accel.SearchForward: "Ctrl-G"' \
+			--merged-file "$MERGED" "$LOCAL" "$BASE" "$REMOTE"
+	else
+		"$merge_tool_path" -X $extra \
+			-R 'Accel.SaveAsMerged: "Ctrl-S"' \
+			-R 'Accel.Search: "Ctrl+F"' \
+			-R 'Accel.SearchForward: "Ctrl-G"' \
+			--merged-file "$MERGED" "$LOCAL" "$REMOTE"
+	fi
+	check_unchanged
+}