Ant PMD and rule exclusion

Question

I have an Ant task to produce a PMD report:

<pmd rulesetfiles="${commons-home}/src/main/resources/pmd/wai_ruleset.xml">
    <formatter type="xml" toFile="${target.reports.pmd}/pmd-report.xml" linkPrefix="${src.main}/"/>
    <fileset dir="${src.main}">
        <include name="**/*.java"/>
    </fileset>  
</pmd>

In wai_ruleset.xml I (try to) exclude NullAssignment from the rules:

<?xml version="1.0"?>
    <ruleset name="WAI rule set"
        xmlns="http://pmd.sf.net/ruleset/1.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0 http://pmd.sf.net/ruleset_xml_schema.xsd"
        xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd">

    <description>
        WAI rules
    </description>

    <!-- imports -->
    <rule ref="rulesets/basic.xml">
        <exclude name="CollapsibleIfStatements"/>
    </rule>
    <rule ref="rulesets/favorites.xml">
        <!-- we redefine it below with a different threshold -->
        <exclude name="CyclomaticComplexity" />
        <!-- empty default constructors are needed by Envers -->
        <exclude name="UnnecessaryConstructor"/>
    </rule>

    <!-- CyclomaticComplexity with a threshold of 12 -->
    <rule ref="rulesets/codesize.xml/CyclomaticComplexity">
        <priority>1</priority>
        <properties>
            <property name="reportLevel" value="12" />
        </properties>
    </rule>

    <rule ref="rulesets/controversial.xml">
        <exclude name="UnnecessaryConstructor"/>
        <exclude name="OnlyOneReturn"/>
        <exclude name="AssignmentInOperand"/>
        <exclude name="BooleanInversion"/>
        <exclude name="NullAssignment"/>
        <exclude name="DataflowAnomalyAnalysis"/>
   </rule>

</ruleset>

If I don't exclude NullAssignment I get two warnings for each assignment to null. If I exclude NullAssignment I still get a warning for each assignment to null.

Which rule is generating the additional warning? Is it a bug?

Answer 1

Check favorites.xml for an inclusion of NullAssignment

Edit: Actually if it's the standard file included with PMD, it has NullAssignment included.