The offending method (Dictionary>>at:put:) has two versions, the most 
recent by cmm. Then I open the MC browser, select Collections package, 
press history, and start moving back through time. Collections-md.18 
discusses a change by Chris Muller (initials fit).

Close history, go back to MC Browser, open the 39a repository, choose 
the offending version, open its history.
Choose the version before it, 17, get a menu, and then a diff between 17 
and 18. See offending methods.

Daniel

stéphane ducasse wrote:
> Daniel
> 
> which cs?
> 
> Stef
> 
>> The other method in the same change set broke finalization in 3.9,  BTW.
>>
>> Daniel
>>
>> stéphane ducasse wrote:
>>
>>> Strange since we did not even introduce the changes of andrew on   
>>> associations....
>>> I will look at that.
>>> Stef
>>> On 18 sept. 05, at 08:48, Andreas Raab wrote:
>>>
>>>> Hi -
>>>>
>>>> Trying out some stuff, I noticed that
>>>>
>>>>   dd := Dictionary new.
>>>>   dd at: nil put: #none.
>>>>
>>>> will raise an error in 3.9a saying that "Dictionaries cannot   
>>>> meaningfully key by nil". That makes no sense. Dictionaries can   
>>>> perfectly contain nil keys, they always have and they always will.
>>>>
>>>> Could somebody please explain to me why we no longer allow a   
>>>> perfectly good key in dictionaries?
>>>>
>>>> Cheers,
>>>>   - Andreas
>>>>
>>>>
>>>>
>>
>>
> 
>