Bug #11213: defined?(super) ignores respond_to_missing?

• Status: Closed
• Assignee: matz (Yukihiro Matsumoto)
• Target version: -
• ruby -v: 2.3dev
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
• Tags: core, maybenotbug

[ko1 (Koichi Sasada)]

class C0
  def method_missing *args
    p [:method_missing] + args
  end
  def respond_to_missing? *args
    true
  end
end

class C1 < C0
  def foo
    super
    defined?(super)
  end
end

p C1.new.foo

This script prints

[:method_missing, :foo]
nil

In this case, we can call super, but defined? returns nil.
It should be a bug.

[ko1 (Koichi Sasada)]

However it is difficult because we can't call self.respond_to_missing? directly because we should ignore C1#respond_to_missing?.

Options:
(1) Ignore this issue as a spec (or known issue)
(2) Do super (it has compatibility issue)
(3) Introduce something special to call respond_to_missing?

My recommendation is (1).

[nobu (Nobuyoshi Nakada)]

https://github.com/ruby/ruby/pull/3777

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|fac2498e0299f13dffe4f09a7dd7657fb49bf643.

---

[Bug #11213] let defined?(super) call respond_to_missing?

[nobu (Nobuyoshi Nakada)]

• Related to Bug #17509: Custom respond_to? methods in modules break defined?(super) added