[GROOVY-6791] Cannot compile Map<K,V> == null

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0, 2.3.1
• Fix Version/s: 2.4.0-beta-4
• Component/s: Static Type Checker
• Assignee: Jochen Theodorou
• Reporter: Yu Kobayashi
• Created: 14/May/14 14:45
• Updated: 17/Dec/14 13:25
• Resolved: 23/Oct/14 14:09

Description

I cannot compile this code with 2.3.0.

import groovy.transform.TypeChecked

@TypeChecked
class TypeTest {
    static interface Map2<K,V> extends Map<K,V> {}

    static void main(String[] args) {
        Map2 map = null
        if (map == null) println "map is null"
    }
}

The error message is

Error:(9, 13) Groovyc: [Static type checking] - Reference to method is ambiguous. Cannot choose between boolean java.util.Map#equals(java.util.Map), boolean java.util.Map <K extends java.lang.Object, V extends java.lang.Object>#equals(java.lang.Object)

I can compile if I change it to this.

if (map == (Object) null)

Also I can compile this too.

Map map = null
if (map == null) println "map is null"