[COLLECTIONS-799] UnmodifiableNavigableSet can be modified by pollFirst() and pollLast()

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.4
• Fix Version/s: 4.5.0-M1
• Component/s: Collection, Set
• External issue URL: https://github.com/apache/commons-collections/pull/250
• Assignee: Bruno P. Kinoshita
• Reporter: Stefano Cordio
• Created: 07/Sep/21 21:07
• Updated: 19/Oct/22 14:31
• Resolved: 09/Oct/21 01:52

Description

pollFirst() and pollLast() are successfully executed and do not throw an UnsupportedOperationException on an UnmodifiableNavigableSet instance.

In my opinion, org.apache.commons.collections4.set.UnmodifiableNavigableSet should have an implementation similar to java.util.Collections.UnmodifiableNavigableSet, where both methods throw an UnsupportedOperationException: https://github.com/openjdk/jdk/blob/708407eddc9d52c01de02e3986c05e1c6225fa85/src/java.base/share/classes/java/util/Collections.java#L1278-L1279

This was detected during working on https://github.com/assertj/assertj-core/pull/2328.