On Sun, Jan 26, 2014 at 10:50 PM, Martin Dias <tinchodias@gmail.com> wrote:

On Sun, Jan 26, 2014 at 4:07 PM, Tudor Girba <tudor@tudorgirba.com> wrote:

I looked more into it, and here is a smaller example:

Gofer new 

smalltalkhubUser: 'Moose' project: 'MooseAlgos';

package: 'Moose-Algos-Graph';

load

This one does open the debugger, so the other emergency evaluator issue comes from somewhere else.

The problem seems to come from a Trait being defined in this package, and loading this trait triggers ClassModifiedClassDefinition which stumbles in 

ClassModifiedClassDefinition>>isPropagation 

"If there is not slot changes, I can assume that there is a propagation (the change is in one of the superclasses)"

self oldClassDefinition layout ifNil: [ ^ false ].

^ self newClassDefinition layout instanceVariables = self oldClassDefinition layout instanceVariables

Despite of the name of ClassModifiedClassDefinition, it is announced also when traits are modified. I don't know if Trait should implement #layout... but it is not.  

I reproduced using this:

Trait named: #DDDD.

Trait 

named: #DDDD 

uses: {TSortable} 

category: 'a'.

I guess that ClassModifiedClassDefinition is not only being announced when a class changed but also it is being announced when its superclass changed (in the case, "propagated"). So the purpose of #isPropagation is the check that. But I'm not sure this announcement should be done for the subclasses...

Yes, when a class is redefined, the change is announced for subclasses also. Maybe we shouldn't, no?

code to reproduce:

aClass := Object subclass: #A.

aClass subclass: #B.

anns := OrderedCollection new.

SystemAnnouncer uniqueInstance 

when: ClassModifiedClassDefinition

send: #add:

to: anns.

Object 

subclass: #A

instanceVariableNames: 'a'.

anns. --->

an OrderedCollection(a ClassModifiedClassDefinition a ClassModifiedClassDefinition)

Mart�n