#1345 UseCollectionIsEmpty throws NullPointerException

[Ville Oikarinen]

PMD prints "Exception applying rule UseCollectionIsEmpty" when analyzing the attached java file.

The top of the printed stacktrace:

  [pmd] java.lang.NullPointerException
  [pmd]     at net.sourceforge.pmd.lang.ast.AbstractNode.jjtGetChild(AbstractNode.java:90)
  [pmd]     at net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck.checkComparison(AbstractInefficientZeroCheck.java:129)
  [pmd]     at net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck.isCompare(AbstractInefficientZeroCheck.java:108)
  [pmd]     at net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck.checkNodeAndReport(AbstractInefficientZeroCheck.java:88)
  [pmd]     at net.sourceforge.pmd.lang.java.rule.AbstractInefficientZeroCheck.visit(AbstractInefficientZeroCheck.java:71)
  [pmd]     at net.sourceforge.pmd.lang.java.ast.ASTVariableDeclaratorId.jjtAccept(ASTVariableDeclaratorId.java:29)

[Ville Oikarinen]

So, there is no crash if "this." is removed from the method call the collection size is compared to.

[Andreas Dangel]

Thanks for the bug report. This will be fixed with the next release of PMD.

Commit: https://github.com/pmd/pmd/commit/171fdb877fa5cfc3225a2b8bbc830bf0ce34041f