clear_meta when clearing guides with the ruler

editor/plugins/canvas_item_editor_plugin.cpp

@@ -1111,7 +1111,11 @@ bool CanvasItemEditor::_gui_input_rulers_and_guides(const Ref<InputEvent> &p_eve
 						if (dragged_guide_index >= 0) {
 							vguides.remove(dragged_guide_index);
 							undo_redo->create_action(TTR("Remove Vertical Guide"));
-							undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_vertical_guides_", vguides);
+							if (vguides.empty()) {
+								undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "remove_meta", "_edit_vertical_guides_");
+							} else {
+								undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_vertical_guides_", vguides);
+							}
 							undo_redo->add_undo_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_vertical_guides_", prev_vguides);
 							undo_redo->add_undo_method(viewport, "update");
 							undo_redo->commit_action();
@@ -1140,7 +1144,11 @@ bool CanvasItemEditor::_gui_input_rulers_and_guides(const Ref<InputEvent> &p_eve
 						if (dragged_guide_index >= 0) {
 							hguides.remove(dragged_guide_index);
 							undo_redo->create_action(TTR("Remove Horizontal Guide"));
-							undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_horizontal_guides_", hguides);
+							if (hguides.empty()) {
+								undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "remove_meta", "_edit_horizontal_guides_");
+							} else {
+								undo_redo->add_do_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_horizontal_guides_", hguides);
+							}
 							undo_redo->add_undo_method(EditorNode::get_singleton()->get_edited_scene(), "set_meta", "_edit_horizontal_guides_", prev_hguides);
 							undo_redo->add_undo_method(viewport, "update");
 							undo_redo->commit_action();