[java] MissingOverride - fix false positive with mixing type vars

[adangel]

Rule: MissingOverride

I found this while trying to run PMD 7 on PMD 7 sources (dogfood).

It addresses the following false positive:

• [INFO] PMD Failure: net.sourceforge.pmd.properties.PropertyBuilder$GenericCollectionPropertyBuilder:402 Rule:MissingOverride Priority:1 The method 'defaultValue(Collection<? extends V>)' is missing an @Override annotation..
  

  pmd/pmd-core/src/main/java/net/sourceforge/pmd/properties/PropertyBuilder.java

  Line 402 in f36b99f

  public GenericCollectionPropertyBuilder<V, C> defaultValue(Collection<? extends V> val) {

The java compiler doesn't allow here an @Override. We would need to use C val instead of Collection<? extends V> val.
While this erased type for both is Collection, the java compiler doesn't see it that way...

[pmd-test]

	2 Messages
📖	Compared to pmd/7.0.x: This changeset changes 0 violations, introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 2 violations, 0 errors and 0 configuration errors. Full report
📖	Compared to master: This changeset changes 48809 violations, introduces 25855 new violations, 5 new errors and 0 new configuration errors, removes 179102 violations, 27 errors and 3 configuration errors. Full report
✅	Compared to pmd/7.0.x: This changeset changes 0 violations, introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 2 violations, 0 errors and 0 configuration errors. Full report
✅	Compared to master: This changeset changes 48809 violations, introduces 25855 new violations, 5 new errors and 0 new configuration errors, removes 179102 violations, 27 errors and 3 configuration errors. Full report
✅	Compared to pmd/7.0.x: This changeset changes 0 violations, introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 2 violations, 0 errors and 0 configuration errors. Full report
✅	Compared to master: This changeset changes 48809 violations, introduces 25855 new violations, 5 new errors and 0 new configuration errors, removes 179102 violations, 27 errors and 3 configuration errors. Full report
✅	Compared to pmd/7.0.x: This changeset changes 0 violations, introduces 4 new violations, 0 new errors and 0 new configuration errors, removes 286 violations, 0 errors and 0 configuration errors. Full report
✅	Compared to master: This changeset changes 45901 violations, introduces 25415 new violations, 38 new errors and 0 new configuration errors, removes 182110 violations, 27 errors and 3 configuration errors. Full report
✅	Compared to pmd/7.0.x: This changeset changes 0 violations, introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 0 violations, 0 errors and 0 configuration errors. Full report
✅	Compared to master: This changeset changes 45977 violations, introduces 25662 new violations, 38 new errors and 0 new configuration errors, removes 182076 violations, 27 errors and 3 configuration errors. Full report

Generated by 🚫 Danger

[oowekyala]

I think this fix is wrong. The thing is, defaultValue(C) and defaultValue(Collection<? extends V>) are override equivalent, so the culprit is not the method areOverrideEquivalent. Rather, MissingOverride should not be checking override equivalence, but instead whether the subclass method is a subsignature of the superclass method, using the method TypeOps.isSubSignature instead of TypeOps.areOverrideEquivalent, as per the spec about overriding