From: E F van de Laar <emiel@...>
Date: 2003-01-24T11:37:52+09:00
Subject: Bug concerning 1.6.8 and hash equality?

I think I may have stumbled upon a bug in Ruby version 1.6.8. This issue
arose by a unit test comparing the equality of different types of hashes.
At first I thought the default behavior of 1.6.8 was correct; hashes
with equal keys and values are equal when compared with "==" and are not
equal if one of those hashes has been instantiated with a default value;
in my case an empty array.

In version 1.6.7 and 1.8.0-pre this behavior differs and both cases
evaluate as true.  An example should make this all clear. :)

emiel@chyrellos:/usr/local/ruby-1.6.8/bin$ ./irb
irb(main):001:0> a = Hash.new []
=> {}
irb(main):002:0> b = {}
=> {}
irb(main):003:0> a == b
=> false
irb(main):004:0> p RUBY_VERSION
"1.6.8"
=> nil

The question is which is the correct behavior? Personally I believe the
behavior of 1.6.7 is correct; a hash is a hash no matter which default
value it carries.

Emiel
-- 
E F van de Laar
+31648183479
www.il.fontys.nl/~emiel