From: Anders Bengtsson <ndrsbngtssn@...>
Date: 2001-01-10T05:14:18+09:00
Subject: [ruby-talk:8956] Re: String confusion

Aleksi Niemel� wrote:
> 
> Robert asks:
> > On Wed, 10 Jan 2001, Yukihiro Matsumoto wrote:
> > > It's a bug.  Here's the patch.  Thank you.
> > >
> > Dave&Andy: Would Rubicon have caught this? How complete is it?
> 
> I just tested with latest 1.7.0 and Rubicon 0.1.4. I'm pretty sure this one
> would have been missed. Here's the tests for String#reverse!:
> 
>   def test_reverse!
>     a="beta"
>     assert_equal("ateb",a.reverse!)
>     assert_equal("ateb",a)
>   end
> 
> As you see, the problem was the side-effect, that reverse! didn't only
> change string pointed by self, but the other (dupped) string too.

I now found a way to reproduce this particular bug without really
looking for side effects:

s = "foo"
s.freeze
s.reverse!

This code happily reverses the string in Ruby 1.6.2, while the CVS
version gives the expected "TypeError: can't modify frozen string".
But I guess that testing every method for how they work with frozen
objects isn't really easier.

/Anders
_____________________________________________________________________
A n d e r s  B e n g t s s o n                   ndrsbngtssn@yahoo.se
Stockholm, Sweden

_____________________________________________________
Do You Yahoo!?
S�lj eller l�gg ett bud p� Yahoo! Auktioner http://se.auctions.yahoo.com