>> I should add, it's already happened.  In 2009 Levente changed
>> Object>>#identityHash to answer the scaledIdentityHash.
>
> Not in Squeak. Our IdentityDictionary uses scaledIdentityHash nowadays, but identityHash itself is left alone, answering the primitive value directly.

I meant to say Object>>#hash, not #identityHash.

So, before 12/1/2009:

     true hash  "2950"

but after 12/1/2009

     true hash  "773324800"

So, any saved persistent EToys ReferenceStream object-models files
with true involved in the calculation of #hash prior to 2009 will now
be goofed up unless you remember to rehash all regular Dictionary's
after loading it.  The properties of this bug are:

  - it is hidden, you had no idea it was there because no SUnit test
can possibly catch it.  It didn't show until production.
  - it is image-specific -- you load the file an image before
Levente's change and everything seems fine.  What's going on?
  - it is "intermittent" because there's a small possibility that, if
the Dictionary were small, you might get lucky with a "hit" anyway
when calculating the slot to start searching at
  - it could lead to corrupt data model, because perhaps the app does
something like #at:ifAbsentPut:, and maybe even on an
otherwise-equivalent object, so you end up with TWO of the "same"
object in the dictionary.  What a disaster!

Now does it make sense?