FULL PRODUCT VERSION :
java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Client VM (build 1.5.0_05-b05, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
The overload resolution mechansm for javac 1.5 seems not to cope with the pattern used in the attached code

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
compile the test application

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
should compile and resolve the overload
ACTUAL -
javac failed, with error deatiled below

ERROR MESSAGES/STACK TRACES THAT OCCUR :
reference to addAll is ambiguous, both method addAll(java.util.Collection<? extends E>) in java.util.Collection<? super A> and method addAll(java.util.Collection<? extends E>) in java.util.List<? super A> match
        l.addAll(getRelated(b));

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Collections;
import java.util.List;


public class Test<A,B> {

    private List<A> getRelated(B b) {
        return Collections.emptyList();
    }
    
    public <L extends List<? super A>> L addOrCreate(B b,L l) {
        l.addAll(getRelated(b));
        return l;
    }
    
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
dont use this pattern, chnage to interfaces, and developed code.
Simplified testcase submitted by another customer:

import java.util.Set;

public class GenericCaptureAddingTest {

    public void test(Set<? super Number> numbers, Set<Number> someNumbers) {
        numbers.addAll(someNumbers);
    }

}