difftool/mergetool: refactor commands to use git-mergetool--lib

This consolidates the common functionality from git-mergetool and
git-difftool--helper into a single git-mergetool--lib scriptlet.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 378 insertions, 0 deletions

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
new file mode 100644
index 0000000000..c5db24e45d
--- /dev/null
+++ b/git-mergetool--lib.sh
@@ -0,0 +1,378 @@
+# git-mergetool--lib is a library for common merge tool functions
+diff_mode() {
+	test "$TOOL_MODE" = diff
+}
+
+merge_mode() {
+	test "$TOOL_MODE" = merge
+}
+
+translate_merge_tool_path () {
+	if test -n "$2"; then
+		echo "$2"
+	else
+		case "$1" in
+		vimdiff)
+			path=vim
+			;;
+		gvimdiff)
+			path=gvim
+			;;
+		emerge)
+			path=emacs
+			;;
+		*)
+			path="$1"
+			;;
+		esac
+		echo "$path"
+	fi
+}
+
+check_unchanged () {
+	if test "$MERGED" -nt "$BACKUP"; then
+		status=0
+	else
+		while true; do
+			echo "$MERGED seems unchanged."
+			printf "Was the merge successful? [y/n] "
+			read answer < /dev/tty
+			case "$answer" in
+			y*|Y*) status=0; break ;;
+			n*|N*) status=1; break ;;
+			esac
+		done
+	fi
+}
+
+valid_tool () {
+	case "$1" in
+	kdiff3 | tkdiff | xxdiff | meld | opendiff | \
+	emerge | vimdiff | gvimdiff | ecmerge | diffuse)
+		;; # happy
+	tortoisemerge)
+		if ! merge_mode; then
+			return 1
+		fi
+		;;
+	kompare)
+		if ! diff_mode; then
+			return 1
+		fi
+		;;
+	*)
+		if test -z "$(get_merge_tool_cmd "$1")"; then
+			return 1
+		fi
+		;;
+	esac
+}
+
+get_merge_tool_cmd () {
+	diff_mode &&
+	custom_cmd="$(git config difftool.$1.cmd)"
+	test -z "$custom_cmd" &&
+	custom_cmd="$(git config mergetool.$1.cmd)"
+	test -n "$custom_cmd" &&
+	echo "$custom_cmd"
+}
+
+run_merge_tool () {
+	base_present="$2"
+	status=0
+
+	case "$1" in
+	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"
+		;;
+	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
+		;;
+	meld)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"
+			check_unchanged
+		else
+			"$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" "$REMOTE" | cat
+		fi
+		;;
+	vimdiff)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" -d -c "wincmd l" \
+				"$LOCAL" "$MERGED" "$REMOTE"
+			check_unchanged
+		else
+			"$merge_tool_path" -d -c "wincmd l" \
+				"$LOCAL" "$REMOTE"
+		fi
+		;;
+	gvimdiff)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" -d -c "wincmd l" -f \
+				"$LOCAL" "$MERGED" "$REMOTE"
+			check_unchanged
+		else
+			"$merge_tool_path" -d -c "wincmd l" -f \
+				"$LOCAL" "$REMOTE"
+		fi
+		;;
+	xxdiff)
+		if merge_mode; then
+			touch "$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" "$REMOTE"
+		fi
+		;;
+	opendiff)
+		if merge_mode; then
+			touch "$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" "$REMOTE" | cat
+		fi
+		;;
+	ecmerge)
+		if merge_mode; then
+			touch "$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
+			"$merge_tool_path" "$LOCAL" "$REMOTE" \
+				--default --mode=merge2 --to="$MERGED"
+		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" "$(basename "$MERGED")"
+		fi
+		;;
+	tortoisemerge)
+		if $base_present; then
+			touch "$BACKUP"
+			"$merge_tool_path" \
+				-base:"$BASE" -mine:"$LOCAL" \
+				-theirs:"$REMOTE" -merged:"$MERGED"
+			check_unchanged
+		else
+			echo "TortoiseMerge cannot be used without a base" 1>&2
+			status=1
+		fi
+		;;
+	*)
+		if test -z "$merge_tool_cmd"; then
+			if merge_mode; then
+				status=1
+			fi
+			break
+		fi
+		if merge_mode; then
+			if test "$merge_tool_trust_exit_code" = "false"; then
+				touch "$BACKUP"
+				( eval $merge_tool_cmd )
+				check_unchanged
+			else
+				( eval $merge_tool_cmd )
+				status=$?
+			fi
+		else
+			( eval $merge_tool_cmd )
+		fi
+		;;
+	esac
+	return $status
+}
+
+guess_merge_tool () {
+	if merge_mode; then
+		tools="tortoisemerge"
+	else
+		tools="kompare"
+	fi
+	if test -n "$DISPLAY"; then
+		if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
+			tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
+		else
+			tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
+		fi
+		tools="$tools gvimdiff diffuse ecmerge"
+	fi
+	if echo "${VISUAL:-$EDITOR}" | grep emacs > /dev/null 2>&1; then
+		# $EDITOR is emacs so add emerge as a candidate
+		tools="$tools emerge vimdiff"
+	elif echo "${VISUAL:-$EDITOR}" | grep vim > /dev/null 2>&1; then
+		# $EDITOR is vim so add vimdiff as a candidate
+		tools="$tools vimdiff emerge"
+	else
+		tools="$tools emerge vimdiff"
+	fi
+	echo >&2 "merge tool candidates: $tools"
+
+	# Loop over each candidate and stop when a valid merge tool is found.
+	for i in $tools
+	do
+		merge_tool_path="$(translate_merge_tool_path "$i")"
+		if type "$merge_tool_path" > /dev/null 2>&1; then
+			merge_tool="$i"
+			break
+		fi
+	done
+
+	if test -z "$merge_tool" ; then
+		echo >&2 "No known merge resolution program available."
+		return 1
+	fi
+	echo "$merge_tool"
+}
+
+get_configured_merge_tool () {
+	# Diff mode first tries diff.tool and falls back to merge.tool.
+	# Merge mode only checks merge.tool
+	if diff_mode; then
+		tool=$(git config diff.tool)
+	fi
+	if test -z "$tool"; then
+		tool=$(git config merge.tool)
+	fi
+	if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
+		echo >&2 "git config option $TOOL_MODE.tool set to unknown tool: $merge_tool"
+		echo >&2 "Resetting to default..."
+		return 1
+	fi
+	echo "$tool"
+}
+
+get_merge_tool_path () {
+	# A merge tool has been set, so verify that it's valid.
+	if ! valid_tool "$merge_tool"; then
+		echo >&2 "Unknown merge tool $merge_tool"
+		exit 1
+	fi
+	if diff_mode; then
+		merge_tool_path=$(git config difftool."$merge_tool".path)
+	fi
+	if test -z "$merge_tool_path"; then
+		merge_tool_path=$(git config mergetool."$merge_tool".path)
+	fi
+	merge_tool_path="$(translate_merge_tool_path "$merge_tool" "$merge_tool_path")"
+	if test -z "$merge_tool_cmd" && ! 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
+	fi
+	echo "$merge_tool_path"
+}
+
+get_merge_tool () {
+	merge_tool="$1"
+	# Check if a merge tool has been configured
+	if test -z "$merge_tool"; then
+		merge_tool=$(get_configured_merge_tool)
+	fi
+	# Try to guess an appropriate merge tool if no tool has been set.
+	if test -z "$merge_tool"; then
+		merge_tool=$(guess_merge_tool) || exit
+	fi
+	echo "$merge_tool"
+}