[GROOVY-11196] ambiguous method error for tap on null receiver

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.19, 5.0.0-alpha-2, 4.0.15
• Fix Version/s: 3.0.20, 5.0.0-alpha-3, 4.0.16

Language

groovy

• Assignee: Eric Milles
• Reporter: Eric Milles
• Created: 16/Oct/23 19:46
• Updated: 22/Dec/23 11:38
• Resolved: 17/Oct/23 19:17

Description

Consider the following:

abstract class A {
  abstract  m(List list, String string)
}
class C extends A {
  @Override m(List list, String string) {
    print 'works'
  }
}

Object test(List list, String string) {
  list.tap {
    new C().m(it,string)
  }
}
test(null,"")

"list.tap{" propagates NullObject into closure and then method selection falls down.

Issue Links

• is related to: GROOVY-4526 NullObject paradoxes
• is related to: GROOVY-4985 null and .with{}
• is related to: GROOVY-6567 delegate is NullObject instance for closure metamethods invoked on null
• is related to: GROOVY-9367 org.codehaus.groovy.runtime.MetaClassHelper#getClassWithNullAndWrapper should return NullObject when accept null