Merge pull request #42044 from Chaosus/vs_fix_regression2

Fix visual shader connection regression

editor/plugins/visual_shader_editor_plugin.cpp

@@ -621,7 +621,7 @@ void VisualShaderGraphPlugin::connect_nodes(VisualShader::Type p_type, int p_fro
 void VisualShaderGraphPlugin::disconnect_nodes(VisualShader::Type p_type, int p_from_node, int p_from_port, int p_to_node, int p_to_port) {
 	if (visual_shader->get_shader_type() == p_type) {
 		VisualShaderEditor::get_singleton()->graph->disconnect_node(itos(p_from_node), p_from_port, itos(p_to_node), p_to_port);
-		if (links[p_to_node].input_ports.has(p_to_port) && links[p_to_node].input_ports[p_to_port].default_input_button != nullptr) {
+		if (links[p_to_node].input_ports.has(p_to_port) && links[p_to_node].input_ports[p_to_port].default_input_button != nullptr && links[p_to_node].visual_node->get_input_port_default_value(p_to_port).get_type() != Variant::NIL) {
 			links[p_to_node].input_ports[p_to_port].default_input_button->show();
 			set_input_port_default_value(p_type, p_to_node, p_to_port, links[p_to_node].visual_node->get_input_port_default_value(p_to_port));
 		}