[ruby-core:69722] [Ruby trunk - Bug #11301] [Open] Module#prepend should have always added the module before the current

Issue #11301 has been reported by Yukihiro Matsumoto.

----------------------------------------
Bug #11301: Module#prepend should have always added the module before the current
https://bugs.ruby-lang.org/issues/11301

* Author: Yukihiro Matsumoto
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
I don't think it's ideal:

 module M
 end  

 class A
   prepend M
 end  

 A.ancestors
 # => [M, A, Object, PP::ObjectMixin, Kernel, BasicObject]

 class B<A
   prepend M
 end  
 B.ancestors
 # => [B, M, A, Object, PP::ObjectMixin, Kernel, BasicObject]

It should be either error (for not adding module) or the module appearing multiple times,
i.e. B.ancestors to be

 [M, B, M, A, Object, PP::ObjectMixin, Kernel, BasicObject]

Matz.




-- 
https://bugs.ruby-lang.org/