Merge branch 'pd/mergetool-nvimdiff'

The existing backends for "git mergetool" based on variants of vim
have been refactored and then support for "nvim" has been added.

* pd/mergetool-nvimdiff:
  mergetools: add support for nvimdiff (neovim) family
  mergetool--lib: improve support for vimdiff-style tool variants

contrib/completion/git-completion.bash

@@ -1712,8 +1712,8 @@ _git_diff ()
 }
 
 __git_mergetools_common="diffuse diffmerge ecmerge emerge kdiff3 meld opendiff
-			tkdiff vimdiff gvimdiff xxdiff araxis p4merge bc
-			codecompare smerge
+			tkdiff vimdiff nvimdiff gvimdiff xxdiff araxis p4merge
+			bc codecompare smerge
 "
 
 _git_difftool ()

git-mergetool--lib.sh

@@ -43,7 +43,14 @@ show_tool_names () {
 
 	shown_any=
 	( cd "$MERGE_TOOLS_DIR" && ls ) | {
-		while read toolname
+		while read scriptname
+		do
+			setup_tool "$scriptname" 2>/dev/null
+			variants="$variants$(list_tool_variants)\n"
+		done
+		variants="$(echo "$variants" | sort | uniq)"
+
+		for toolname in $variants
 		do
 			if setup_tool "$toolname" 2>/dev/null &&
 				(eval "$condition" "$toolname")
@@ -157,6 +164,10 @@ setup_tool () {
 		echo "$1"
 	}
 
+	list_tool_variants () {
+		echo "$tool"
+	}
+
 	# Most tools' exit codes cannot be trusted, so By default we ignore
 	# their exit code and check the merged file's modification time in
 	# check_unchanged() to determine whether or not the merge was
@@ -178,19 +189,26 @@ setup_tool () {
 		false
 	}
 
-
-	if ! test -f "$MERGE_TOOLS_DIR/$tool"
+	if test -f "$MERGE_TOOLS_DIR/$tool"
+	then
+		. "$MERGE_TOOLS_DIR/$tool"
+	elif test -f "$MERGE_TOOLS_DIR/${tool%[0-9]}"
 	then
+		. "$MERGE_TOOLS_DIR/${tool%[0-9]}"
+	else
 		setup_user_tool
 		return $?
 	fi
 
-	# Load the redefined functions
-	. "$MERGE_TOOLS_DIR/$tool"
 	# Now let the user override the default command for the tool.  If
 	# they have not done so then this will return 1 which we ignore.
 	setup_user_tool
 
+	if ! list_tool_variants | grep -q "^$tool$"
+	then
+		return 1
+	fi
+
 	if merge_mode && ! can_merge
 	then
 		echo "error: '$tool' can not be used to resolve merges" >&2
@@ -286,11 +304,14 @@ list_merge_tool_candidates () {
 		tools="$tools smerge"
 	fi
 	case "${VISUAL:-$EDITOR}" in
+	*nvim*)
+		tools="$tools nvimdiff vimdiff emerge"
+		;;
 	*vim*)
-		tools="$tools vimdiff emerge"
+		tools="$tools vimdiff nvimdiff emerge"
 		;;
 	*)
-		tools="$tools emerge vimdiff"
+		tools="$tools emerge vimdiff nvimdiff"
 		;;
 	esac
 }

mergetools/bc

@@ -21,3 +21,8 @@ translate_merge_tool_path() {
 		echo bcompare
 	fi
 }
+
+list_tool_variants () {
+	echo bc
+	echo bc3
+}

mergetools/vimdiff

@@ -5,7 +5,7 @@ diff_cmd () {
 
 merge_cmd () {
 	case "$1" in
-	gvimdiff|vimdiff)
+	*vimdiff)
 		if $base_present
 		then
 			"$merge_tool_path" -f -d -c '4wincmd w | wincmd J' \
@@ -15,11 +15,11 @@ merge_cmd () {
 				"$LOCAL" "$MERGED" "$REMOTE"
 		fi
 		;;
-	gvimdiff2|vimdiff2)
+	*vimdiff2)
 		"$merge_tool_path" -f -d -c 'wincmd l' \
 			"$LOCAL" "$MERGED" "$REMOTE"
 		;;
-	gvimdiff3|vimdiff3)
+	*vimdiff3)
 		if $base_present
 		then
 			"$merge_tool_path" -f -d -c 'hid | hid | hid' \
@@ -34,10 +34,13 @@ merge_cmd () {
 
 translate_merge_tool_path() {
 	case "$1" in
-	gvimdiff|gvimdiff2|gvimdiff3)
+	nvimdiff*)
+		echo nvim
+		;;
+	gvimdiff*)
 		echo gvim
 		;;
-	vimdiff|vimdiff2|vimdiff3)
+	vimdiff*)
 		echo vim
 		;;
 	esac
@@ -46,3 +49,11 @@ translate_merge_tool_path() {
 exit_code_trustable () {
 	true
 }
+
+list_tool_variants () {
+	for prefix in '' g n; do
+		for suffix in '' 2 3; do
+			echo "${prefix}vimdiff${suffix}"
+		done
+	done
+}