http://dev.clojure.org/jira This file is an XML representation of an issue en-us 4.4 649 25-07-2011 http://dev.clojure.org/jira/browse/CLJ-702 Clojure <p>This code gives a NullPointerException:</p> <p>(case nil<br/> nil "foo")</p> <p>If fixing this is impossible for implementation reasons, at least the documentation and error messages should be improved.</p> CLJ-702

case gives NPE when used with nil

Defect Major Closed Completed Unassigned Benjamin Teuber Tue, 4 Jan 2011 09:02:13 -0600 Fri, 25 Feb 2011 15:06:28 -0600 Fri, 25 Feb 2011 15:06:28 -0600 Release 1.2 Release 1.3 1 1 <p>What would be the desired fix look like for this? Should this be a documentation update or should this be updated to not produce an NPE?</p> <p>I think that the case macro should just generate a null check before calling hashcode on a value. The same way protocol functions automatically check for null before dispatching.</p> <p>First step in fixing a problem is to understand it. The exception is thrown during compilation and the stack trace points to c.l.Compiler$ObjExpression.constantType()</p> <p>Thanks Rich. I will take this one and get a patch in hopefully today.</p> <p>Rich, this seems to solve the issue demonstrated in this ticket. I don't have full context on all possible impact points here. Can you please take a look at this and let me know if I missed anything?</p> <p>looks ok at first glance</p> <p>New patch 0702-fix-npe-in-nil-case-2.patch.gz adds a test.</p> <p>Stuart, your patch replaces the original patch and the commit message doesn't reveal the intent of the fix. It also overwrites me as the original patch submitter.</p> <p>Oops. Sorry. Will fix.</p> <p>waiting on Stuart's patch tweak</p> <p>Patch 0702-fix-npe-in-nil-case-3.patch.gz replaces previous patches, but preserves correct commit messages and authors.</p> Approval Ok Global Rank Patch Code and Test