Bug #7290: Overriding method_added on a refinement's anonymous module can cause the opt_* opcodes to behave incorrectly

• Status: Closed
• Assignee: shugo (Shugo Maeda)
• Target version: 2.0.0
• ruby -v: 2.0.0-preview1

Ruby stores flags in (({ruby_vm_redefined_flag})) to track whether certain methods have been redefined on particular classes. If the redefined flag for a certain class and operator is not set, Ruby will skip method lookup and directly call the method implementing that operator.

The current implementation of refinements uses the (({method_added})) callback to set these flags. If this method is overridden, the flags are not set properly.

This code should raise a RuntimeError with the message "addition is not allowed". Instead it outputs "3". If line 3 is removed, it behaves correctly.

module Test
refine Fixnum do
def self.method_added(id); end

  def +(other)
    raise "addition is not allowed"
  end
end

end

using Test

puts 1 + 2

[ko1 (Koichi Sasada)]

• Category set to core
• Assignee set to shugo (Shugo Maeda)
• Target version set to 2.0.0

[shugo (Shugo Maeda)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r37534.
Charlie, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• eval.c (rb_mod_refine): set RMODULE_IS_REFINEMENT to a created
  refinement module, and don't override method_added.

• vm_method.c (rb_method_entry_make): check redefinition of
  optimized methods when a method is added to a refinement module.
  [ruby-core:48970] [Bug #7290]

• test/ruby/test_refinement.rb: related test.