Bug #9381: 2.1.0 Regression. Hash lookup with #hash and #eql?

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: -
• ruby -v: ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-linux]
• Backport: 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: DONE, 2.2: DONE

[nick78 (Nick S)]

Ruby 2.1.0 won't fetch objects when the lookup key overrides #hash and #eql?.
This is a regression as it works as expected in ruby 1.8, 1.9 and 2.0.

class Wrapper
  def initialize(obj)
    @obj = obj
  end

  def method_missing(symbol, *args, &block)
    @obj.__send__(symbol, *args, &block)
  end

  def hash
    @obj.hash
  end

  def eql?(other)
    @obj.eql?(other)
  end
end

hash = { 5 => "LOOKUP SUCCEEDED" }

# Prints "LOOKUP SUCCEEDED" on RUBY < 2.1.0. Fails on RUBY 2.1.0.
p hash[Wrapper.new(5)]

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)
• Status changed from Open to Assigned
• Assignee set to nobu (Nobuyoshi Nakada)
• Target version set to 2.2.0
• Backport changed from 1.9.3: UNKNOWN, 2.0.0: UNKNOWN, 2.1: UNKNOWN to 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED

[nobu (Nobuyoshi Nakada)]

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

This issue was solved with changeset r44525.
Nick, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

object.c: hash value from objid with salt

• hash.c (rb_objid_hash): return hash value from object ID with a
  salt, extract from rb_any_hash().
• object.c (rb_obj_hash): return same value as rb_any_hash().
  fix r44125. [ruby-core:59638] [Bug #9381]

[naruse (Yui NARUSE)]

• Backport changed from 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED to 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: DONE

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: DONE to 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED, 2.2: REQUIRED

I re-fill Backport field for r51425. I'm not sure if this is bugfix or feature change though.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED, 2.2: REQUIRED to 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED, 2.2: DONE

I additionally backport r51425 into ruby_2_2 branch at r51572.

[usa (Usaku NAKAMURA)]

• Backport changed from 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: REQUIRED, 2.2: DONE to 1.9.3: DONTNEED, 2.0.0: DONTNEED, 2.1: DONE, 2.2: DONE

ruby_2_1 r51613 merged revision(s) 51423,51425.