ES_COMPARING_STRINGS_WITH_EQ possibly not detected

[DAGobertGans]

So I have the following java code to test whether the spotbugs maven and eclipse plugins behave as expected:

String a = "", b = "";
if (a == b);
String[] c = {""}, d = {""};
if (c.equals(d));

Now neither plugin reports the ES_COMPARING_STRINGS_WITH_EQ bug
but both do report the EC_BAD_ARRAY_COMPARE bug.
version 3.1.6, default effort level
What did I miss?