[GROOVY-7016] AutoClone does not check for existing copy constructor

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.0-beta-2
• Fix Version/s: 2.3.7, 2.4.0-beta-3
• Component/s: groovy-jdk
• Labels: ClassFormatError
• Assignee: Paul King
• Reporter: Venkat Srinivasan
• Created: 08/Aug/14 13:09
• Updated: 22/May/22 16:05
• Resolved: 09/Aug/14 05:58

Description

@AutoClone with COPY_CONSTRUCTOR style does not check if a copy constructor already exists. There are times when the author may want to write their own copy constructor.

Please see example below:

import groovy.transform.AutoClone
import groovy.transform.AutoCloneStyle

@AutoClone(style = AutoCloneStyle.COPY_CONSTRUCTOR)
class MyClass {
  MyClass(MyClass other) {
    println 'custom copy constructor'
  }
}

If we compile and examine the generated code, we see duplication:

> groovyc MyClass.groovy 
> javap -c MyClass | grep "MyClass("
  protected MyClass(MyClass);
  protected MyClass(MyClass);
> 

This leads to compilation error later when MyClass.class is used in another code, like so,

Caught: java.lang.ClassFormatError: Duplicate method name&signature in class file MyClass
java.lang.ClassFormatError: Duplicate method name&signature in class file MyClass