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Bug #5236

Including a module in a superclass after it has been included in a subclass leads to infinite recursion if the module uses `super`

Added by myronmarston (Myron Marston) about 6 years ago. Updated almost 5 years ago.

Status:
Closed
Priority:
Normal
Target version:
ruby -v:
1.9.x
[ruby-core:39132]

Description

Under these particular circumstances, you get infinite recursion and a system stack error on 1.9 but not 1.8:

  • Create a module that has a method that uses super
  • Include that module in a class after it has already been included in one of its subclasses
  • Instantiate an object of said subclass and call the method

On 1.8, the super works as expected. On 1.9 you get a SystemStackError. Here's example code that demonstrates the issue:

example.rb

module MyModule
def some_method; super; end
end

class MyBaseClass; end

class MySubClass < MyBaseClass;
include MyModule
end

To trigger this bug, we must include the module in the base class after

the module has already been included in the subclass. If we move this line

above the subclass declaration, this bug will not occur.

MyBaseClass.send(:include, MyModule)

MySubClass.new.some_method

The output

➜ ruby --version
ruby 1.8.7 (2011-02-18 patchlevel 334) [i686-darwin10.6.0]
➜ ruby example.rb
example.rb:2:in some_method': super: no superclass methodsome_method' for #MySubClass:0x1001bc2d0 (NoMethodError)
from example.rb:2:in `some_method'
from example.rb:13

➜ ruby --version
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.6.0]
➜ ruby example.rb
example.rb:2: stack level too deep (SystemStackError)

I've tried it on 1.9.3.preview-1 and I get the SystemStackError there, too. I would expect 1.9 to act like 1.8 here, and not infinitely recurse on itself.


Related issues

Related to Ruby trunk - Bug #3351: stack overflow on superClosed
Related to Ruby trunk - Feature #1586: Including a module already present in ancestors should not be ignoredAssigned

History

#1 [ruby-core:40542] Updated by pda (Paul Annesley) about 6 years ago

This bug causes a lot of trouble for RSpec developers and end users alike:
https://github.com/rspec/rspec-rails/issues/371#issuecomment-1430232

It'd be great to see it fixed on Ruby's side.

Cheers!
Paul

#2 [ruby-core:43175] Updated by ko1 (Koichi Sasada) over 5 years ago

  • Assignee set to ko1 (Koichi Sasada)
  • Target version set to 2.0.0

#3 Updated by shyouhei (Shyouhei Urabe) over 5 years ago

  • Status changed from Open to Assigned

#4 [ruby-core:50128] Updated by ko1 (Koichi Sasada) almost 5 years ago

  • Assignee changed from ko1 (Koichi Sasada) to nobu (Nobuyoshi Nakada)

nobu, could you check it?

#5 [ruby-core:51581] Updated by nobu (Nobuyoshi Nakada) almost 5 years ago

  • Status changed from Assigned to Closed

Already fixed probably at r36595 etc.

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