Fix converting to tileset crashes Godot if existing file is not tileset

also make TileSetEditorPlgn tile list updates the preview modulate

doc/classes/ItemList.xml

@@ -87,6 +87,15 @@
 			<description>
 			</description>
 		</method>
+		<method name="get_item_icon_modulate" qualifiers="const">
+			<return type="Color">
+			</return>
+			<argument index="0" name="idx" type="int">
+			</argument>
+			<description>
+				Returns a [Color] modulating item's icon at the specified index.
+			</description>
+		</method>
 		<method name="get_item_icon_region" qualifiers="const">
 			<return type="Rect2">
 			</return>
@@ -225,6 +234,17 @@
 				Set (or replace) icon of the item at the specified index.
 			</description>
 		</method>
+		<method name="set_item_icon_modulate">
+			<return type="void">
+			</return>
+			<argument index="0" name="idx" type="int">
+			</argument>
+			<argument index="1" name="modulate" type="Color">
+			</argument>
+			<description>
+				Sets a modulating [Color] for item's icon at the specified index.
+			</description>
+		</method>
 		<method name="set_item_icon_region">
 			<return type="void">
 			</return>

editor/editor_node.cpp

@@ -1227,29 +1227,25 @@ void EditorNode::_dialog_action(String p_file) {
 		} break;
 		case FILE_EXPORT_TILESET: {
 
-			Ref<TileSet> ml;
-			if (FileAccess::exists(p_file)) {
-				ml = ResourceLoader::load(p_file, "TileSet");
+			Ref<TileSet> tileset;
+			if (FileAccess::exists(p_file) && file_export_lib_merge->is_pressed()) {
+				tileset = ResourceLoader::load(p_file, "TileSet");
 
-				if (ml.is_null()) {
-					if (file_export_lib_merge->is_pressed()) {
+				if (tileset.is_null()) {
 					current_option = -1;
 					accept->get_ok()->set_text(TTR("I see.."));
 					accept->set_text(TTR("Can't load TileSet for merging!"));
 					accept->popup_centered_minsize();
 					return;
 				}
-				} else if (!file_export_lib_merge->is_pressed()) {
-					ml->clear();
-				}
 
 			} else {
-				ml = Ref<TileSet>(memnew(TileSet));
+				tileset = Ref<TileSet>(memnew(TileSet));
 			}
 
-			TileSetEditor::update_library_file(editor_data.get_edited_scene_root(), ml, true);
+			TileSetEditor::update_library_file(editor_data.get_edited_scene_root(), tileset, true);
 
-			Error err = ResourceSaver::save(p_file, ml);
+			Error err = ResourceSaver::save(p_file, tileset);
 			if (err) {
 
 				current_option = -1;

editor/plugins/tile_set_editor_plugin.cpp

@@ -278,10 +278,11 @@ void TileSetEditor::_changed_callback(Object *p_changed, const char *p_prop) {
 		preview->set_region_rect(tileset->tile_get_region(get_current_tile()));
 	} else if (p_prop == StringName("name")) {
 		update_tile_list_icon();
-	} else if (p_prop == StringName("texture") || p_prop == StringName("tile_mode")) {
+	} else if (p_prop == StringName("texture") || p_prop == StringName("modulate") || p_prop == StringName("tile_mode")) {
 		_on_tile_list_selected(get_current_tile());
 		workspace->update();
 		preview->set_texture(tileset->tile_get_texture(get_current_tile()));
+		preview->set_modulate(tileset->tile_get_modulate(get_current_tile()));
 		preview->set_region_rect(tileset->tile_get_region(get_current_tile()));
 		if (tileset->tile_get_tile_mode(get_current_tile()) == TileSet::AUTO_TILE)
 			property_editor->show();
@@ -578,6 +579,7 @@ void TileSetEditor::_on_tile_list_selected(int p_index) {
 	if (get_current_tile() >= 0) {
 		current_item_index = p_index;
 		preview->set_texture(tileset->tile_get_texture(get_current_tile()));
+		preview->set_modulate(tileset->tile_get_modulate(get_current_tile()));
 		preview->set_region_rect(tileset->tile_get_region(get_current_tile()));
 		workspace->set_custom_minimum_size(tileset->tile_get_region(get_current_tile()).size);
 		update_workspace_tile_mode();
@@ -1736,6 +1738,7 @@ void TileSetEditor::update_tile_list() {
 			region.position += pos;
 		}
 		tile_list->set_item_icon_region(tile_list->get_item_count() - 1, region);
+		tile_list->set_item_icon_modulate(tile_list->get_item_count() - 1, tileset->tile_get_modulate(E->get()));
 	}
 	if (tile_list->get_item_count() > 0 && selected_tile < tile_list->get_item_count()) {
 		tile_list->select(selected_tile);
@@ -1763,6 +1766,7 @@ void TileSetEditor::update_tile_list_icon() {
 		tile_list->set_item_metadata(current_idx, E->get());
 		tile_list->set_item_icon(current_idx, tileset->tile_get_texture(E->get()));
 		tile_list->set_item_icon_region(current_idx, region);
+		tile_list->set_item_icon_modulate(current_idx, tileset->tile_get_modulate(E->get()));
 		tile_list->set_item_text(current_idx, tileset->tile_get_name(E->get()));
 		current_idx += 1;
 	}

scene/gui/item_list.cpp

@@ -37,6 +37,7 @@ void ItemList::add_item(const String &p_item, const Ref<Texture> &p_texture, boo
 	Item item;
 	item.icon = p_texture;
 	item.icon_region = Rect2i();
+	item.icon_modulate = Color(1, 1, 1, 1);
 	item.text = p_item;
 	item.selectable = p_selectable;
 	item.selected = false;
@@ -54,6 +55,7 @@ void ItemList::add_icon_item(const Ref<Texture> &p_item, bool p_selectable) {
 	Item item;
 	item.icon = p_item;
 	item.icon_region = Rect2i();
+	item.icon_modulate = Color(1, 1, 1, 1);
 	//item.text=p_item;
 	item.selectable = p_selectable;
 	item.selected = false;
@@ -138,6 +140,21 @@ Rect2 ItemList::get_item_icon_region(int p_idx) const {
 	return items[p_idx].icon_region;
 }
 
+void ItemList::set_item_icon_modulate(int p_idx, const Color &p_modulate) {
+
+	ERR_FAIL_INDEX(p_idx, items.size());
+
+	items[p_idx].icon_modulate = p_modulate;
+	update();
+}
+
+Color ItemList::get_item_icon_modulate(int p_idx) const {
+
+	ERR_FAIL_INDEX_V(p_idx, items.size(), Color());
+
+	return items[p_idx].icon_modulate;
+}
+
 void ItemList::set_item_custom_bg_color(int p_idx, const Color &p_custom_bg_color) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
@@ -1045,7 +1062,7 @@ void ItemList::_notification(int p_what) {
 					draw_rect.size = adj.size;
 				}
 
-				Color modulate = Color(1, 1, 1, 1);
+				Color modulate = items[i].icon_modulate;
 				if (items[i].disabled)
 					modulate.a *= 0.5;
 
@@ -1389,6 +1406,9 @@ void ItemList::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_item_icon_region", "idx", "rect"), &ItemList::set_item_icon_region);
 	ClassDB::bind_method(D_METHOD("get_item_icon_region", "idx"), &ItemList::get_item_icon_region);
 
+	ClassDB::bind_method(D_METHOD("set_item_icon_modulate", "idx", "modulate"), &ItemList::set_item_icon_modulate);
+	ClassDB::bind_method(D_METHOD("get_item_icon_modulate", "idx"), &ItemList::get_item_icon_modulate);
+
 	ClassDB::bind_method(D_METHOD("set_item_selectable", "idx", "selectable"), &ItemList::set_item_selectable);
 	ClassDB::bind_method(D_METHOD("is_item_selectable", "idx"), &ItemList::is_item_selectable);
 

scene/gui/item_list.h

@@ -54,6 +54,7 @@ private:
 
 		Ref<Texture> icon;
 		Rect2i icon_region;
+		Color icon_modulate;
 		Ref<Texture> tag_icon;
 		String text;
 		bool selectable;
@@ -135,6 +136,9 @@ public:
 	void set_item_icon_region(int p_idx, const Rect2 &p_region);
 	Rect2 get_item_icon_region(int p_idx) const;
 
+	void set_item_icon_modulate(int p_idx, const Color &p_modulate);
+	Color get_item_icon_modulate(int p_idx) const;
+
 	void set_item_selectable(int p_idx, bool p_selectable);
 	bool is_item_selectable(int p_idx) const;
 

scene/resources/tile_set.cpp

@@ -347,6 +347,7 @@ void TileSet::tile_set_modulate(int p_id, const Color &p_modulate) {
 	ERR_FAIL_COND(!tile_map.has(p_id));
 	tile_map[p_id].modulate = p_modulate;
 	emit_changed();
+	_change_notify("modulate");
 }
 
 Color TileSet::tile_get_modulate(int p_id) const {