A DESCRIPTION OF THE PROBLEM :
Since enum nested classes in enum classes are also counted as constants, switch expressions containing outer enum classes can never be compiled.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
javac SwitchEnumBug.java

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
SwitchEnumBug.java:8: error: the switch expression does not cover all possible input values
                var result = switch (A) {
                             ^
1 error

---------- BEGIN SOURCE ----------
public enum SwitchEnumBug {
A;
public enum InnerEnum { }
static {
var result = switch (A) {
case A -> A;
};
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
https://github.com/AdoptOpenJDK/openjdk-jdk/blob/master/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java#L702
Attach the filter to condition (&& s.kind == VAR)

FREQUENCY : always