JDK-8023367 : Collections.emptyList().sort((Comparator)null) throws NPE
  • Type: Bug
  • Component: core-libs
  • Sub-Component: java.util:collections
  • Affected Version: 8
  • Priority: P3
  • Status: Closed
  • Resolution: Fixed
  • Submitted: 2013-08-20
  • Updated: 2013-08-30
  • Resolved: 2013-08-20
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JDK 8
8 b105Fixed
Related Reports
Relates :  
JDK-8001647 - default methods for Collections - forEach, removeIf, replaceAll, sort
Description
The following line

        Collections.emptyList().sort((Comparator)null);

Leads to

Exception in thread "main" java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at java.util.Collections$EmptyList.sort(Collections.java:4523)

While the spec on j.u.List.sort(Comparator) says:
"A null value indicates that the elements' natural ordering should be used"


In the implementation this looks like a result of a copy-paste mistake.

The following JCK test will fail:

api/java_util/Collections/empty/EmptyListSort.html#EmptyListSort[elementSettingNotSupported_naturalSorting]