FULL PRODUCT VERSION :


A DESCRIPTION OF THE PROBLEM :
The replaceAll method of a list returned by java.util.Collections.checkedList passes the replacement operator directly to the underlying list, enabling violation of the type checking.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.*;
import java.util.function.UnaryOperator;

class CheckedListViolationBug {
    public static void main(String... args) {
        // Create a runtime-checked List of Integers only
        List<Integer> integersOnly = Collections.checkedList(new ArrayList<>(), Integer.class);
        integersOnly.add(1);
        integersOnly.add(2);
        integersOnly.add(3);
        
        // the UnaryOperator bypasses the check, enabling insertion of arbitrary elements
        integersOnly.replaceAll((UnaryOperator)(e -> "ha!"));
        
        // the list now contains Strings:
        System.out.println(integersOnly);
    }
}
---------- END SOURCE ----------