On 1 April 2013 23:06, Colin Putney <colin at wiresong.com> wrote:
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> On Mon, Apr 1, 2013 at 2:07 PM, Frank Shearar <frank.shearar at gmail.com>
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>> Right. That tells me there's an Alias still pointing to the XMLWriter
>> class. So my half-baked theory is that something's missing in the
>> Environment work and how it integrates with Monticello?
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> I don't think that's it. I mean sure, Environments is incomplete and buggy,
> but the behaviour you describe can happen in Squeak 4.4 too. If there are
> any instances of XMLWriter when you unload the class, they get migrated to
> obsolete instances. The thing to do is, as Eliot suggested, figure out
> what's pointing to them and how to sever those references before you unload
> the class.

And what's pointing to the class is an Alias. In a normally updated
image (one in which XML-Parser has not been removed, PointerFinder
shows a single path to XMLWriter:

CLASS: SmalltalkImage class
superclass: Object class
subclasses: Array
383: XMLWriter class

If I hack Environment >> #forgetClass:logged: and Environment >>
#removeClass: to dump their arguments to the Transcript I can see that
they're called. This invalidates my Environments-Monticello
integration hypothesis: the bug, whatever it is, lies in Environment.
After an unload (Monticello browser, right click, unload),
PointerFinder on: XMLWriter says:

globals: Environment
bindings: IdentityDictionary
array: Array
1301: Alias
source: Association
value: AnObsoleteXMLWriter class

Of course, you should not even be able to evaluate "PointerFinder on:
XMLWriter" - the class is supposed to be gone, and you should be told
"there's no such class".

So my next hypothesis is that unloading the package doesn't remove the
association from the top level Environment's bindings instvar.

frank

> Colin
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