[GROOVY-9367] org.codehaus.groovy.runtime.MetaClassHelper#getClassWithNullAndWrapper should return NullObject when accept null

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.6
• Fix Version/s: 5.0.0-alpha-3
• Component/s: groovy-runtime
• Assignee: Eric Milles
• Reporter: XJ Chen
• Created: 17/Jan/20 04:40
• Updated: 22/Dec/23 11:38
• Resolved: 17/Oct/23 16:30

Description

I have a extension class

class NumberExtension {
    static Integer plus(Integer self, NullObject right) {
        return self;
    }
}

However

1 + null

will throw

Ambiguous method overloading for method java.lang.Integer#plus

Because org.codehaus.groovy.runtime.MetaClassHelper#getClassWithNullAndWrapper return null for null argument. Then org.codehaus.groovy.runtime.MetaClassHelper#calculateParameterDistance(java.lang.Class, org.codehaus.groovy.reflection.CachedClass) doesn't return 0 because null != NullObject.class

Issue Links

• relates to: GROOVY-11196 ambiguous method error for tap on null receiver
• links to: GitHub Pull Request #1147