The following NULL check is unnecessary. This function is called only in two places, which always pass in a non-NULL ik parameter.

https://github.com/openjdk/jdk/blob/77c3bbf105403089fec69d51406fe3e6f562271f/src/hotspot/share/cds/cdsProtectionDomain.cpp#L52

Handle CDSProtectionDomain::init_security_info(Handle class_loader, InstanceKlass* ik, PackageEntry* pkg_entry, TRAPS) {
  Handle pd;

  if (ik != NULL) { ...