FULL PRODUCT VERSION :
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux titan 2.6.34.10-26906-default #1 SMP 2012-05-28 16:10:01 +0200 x86_64 x86_64 x86_64 GNU/Linux


A DESCRIPTION OF THE PROBLEM :
The javac compiler rejects this valid Java program:

public class xx {

    interface PublicCloneable {
        Object clone();
    }

    interface HasPosition {
        int getPosition();
        void setPosition(int p);
    }

    @SuppressWarnings("unchecked")
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
        final E clone = (E)elem.clone();
        clone.setPosition(clone.getPosition() + 1);
        return clone;
    }
}

Errors reported:

xx.java:13: error: clone() in Object cannot implement clone() in PublicCloneable
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
     ^
  attempting to assign weaker access privileges; was public
xx.java:14: error: clone() has protected access in Object
        final E clone = (E)elem.clone();
                               ^
2 errors


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Try to compile this program:

public class xx {

    interface PublicCloneable {
        Object clone();
    }

    interface HasPosition {
        int getPosition();
        void setPosition(int p);
    }

    @SuppressWarnings("unchecked")
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
        final E clone = (E)elem.clone();
        clone.setPosition(clone.getPosition() + 1);
        return clone;
    }
}


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Program compiles successfully.
ACTUAL -
xx.java:13: error: clone() in Object cannot implement clone() in PublicCloneable
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
     ^
  attempting to assign weaker access privileges; was public
xx.java:14: error: clone() has protected access in Object
        final E clone = (E)elem.clone();
                               ^
2 errors


ERROR MESSAGES/STACK TRACES THAT OCCUR :
xx.java:13: error: clone() in Object cannot implement clone() in PublicCloneable
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
     ^
  attempting to assign weaker access privileges; was public
xx.java:14: error: clone() has protected access in Object
        final E clone = (E)elem.clone();
                               ^
2 errors


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class xx {

    interface PublicCloneable {
        Object clone();
    }

    interface HasPosition {
        int getPosition();
        void setPosition(int p);
    }

    @SuppressWarnings("unchecked")
    <E extends PublicCloneable & HasPosition> E cloneAndIncrementPosition(E elem) {
        final E clone = (E)elem.clone();
        clone.setPosition(clone.getPosition() + 1);
        return clone;
    }
}

---------- END SOURCE ----------