glib: integer underflow in gio/gdbusintrospection.c via "g_dbus_node_info_new_for_xml"

A flaw was found in GLib. A state confusion issue exists in gdbusnodeinfonewforxml in the gio/gdbusintrospection.c file when processing malformed D-Bus introspection XML, specifically with a node element nested within other elements like method, signal, property or arg. This issue can cause an...