2017-04-08 17:14 GMT+02:00 Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com>:

>
>
> 2017-04-08 14:09 GMT+02:00 David T. Lewis <lewis at mail.msen.com>:
>
>> On Sat, Apr 08, 2017 at 01:59:34PM +0200, Nicolas Cellier wrote:
>> > Ah, but now that I've put a
>> >     (selector == #unwindTo: and: [ self name = 'Context']) ifTrue:[self
>> > halt: 'debug me'].
>> > I can't reproduce the problem related to removal of Context methods!!!
>> >
>> > Instead, I've got the 'Merging Kernel-eem.1078' window with all the
>> > MethodContext->Context renaming in conflict
>> > I already reported that in another thread where I told that the upgrade
>> > went "smoothly" for both my 32 & 64 bits images.
>> > I don't know if it's related to package cache, or .mcd, or ???
>> >
>> > It might also be that package ancestry is not correct du to overwriting
>> of
>> > some packages, otherwise we should not get a merge window, but well...
>> >
>> > Ah, but now I think I understand: it's just because I have pending
>> changes
>> > in Kernel due to the addition of halt: above (same for my images which
>> > usually have some unpublished experiments).
>> > We then trigger a merge rather than a load. And the merge sees conflict
>> > probably because of broken ancestry (the GUID are not corresponding),
>> but
>> > once resolved manually, it processes smoothly without removing Context
>> > methods...
>> >
>> > I can't instrument code that easily... This will have to wait for
>> another
>> > time slot :(
>> >
>>
>> Nicolas,
>>
>> Thanks very much for working on this and for posting your results so far.
>> This is not an easy problem to solve.
>>
>> Dave
>>
>>
>> Hi Dave,
> don't worry, real show stopper obstacles are rare, the rest of them make
> the game more fun ;)
> So I've put the halt in MethodContext class>>removeSelector:  in a *Debug
> protocol so as to keep Kernel clean, and I've now got the stack at the
> point of removing what should not be removed.
>
> It's in MCDiffyVersion load -> MCVersionLoader load -> MCPackageLoader
> load.
>
> There's a bunch of removals, starting with:
>
> an OrderedCollection(a MCMethodDefinition(MethodContext>>unwindTo:)
> a MCMethodDefinition(MethodContext>>tryPrimitiveFor:receiver:args:)
> a MCMethodDefinition(MethodContext>>tryNamedPrimitiveIn:for:withArgs:)
> a MCMethodDefinition(MethodContext>>top)
> a MCMethodDefinition(MethodContext>>terminateTo:) ...
>
> So yes, this mcd is going to shoot the update process.
> Why is it different from the load or merge triggered manually?
> Can't we avoid all the method removals and keep only the class removal?
>
> I can try this snippet in the MCPackageLoader to reject some superfluous
> method removals:
>
> |  removedClasses |
> removedClasses := (removals select: #isClassDefinition) collect:
> #actualClass.
> removedClasses addAll: (removedClasses collect: #class).
> removals := removals reject: [:e | e isMethodDefinition and:
> [removedClasses includes: e actualClass]]
>
> Is it OK as a general change in MC?
>
> Then I'm not sure how it's going to work, because at this stage, Context
> is still a subclass of ContextPart as I told before (though it has a
> different superclass), and #MethodContext is still pointing to Context, so
> removing either one or the other is going to lead to problems again...
>
> So two more hacks might be necessary:
>
> [Smalltalk globals at: #MethodContext put: Context copy] on:
> AttemptToWriteReadOnlyGlobal do: [:exc | exc resume: true].
>
> ContextPart instVarAt: 6 put: (ContextPart subclasses select: [:e | e
> superclass = ContextPart]).
>
> Finally, with the 2nd hack, maybe I don't need to forget the superfluous
> method removals.
> However, it failed when I tried, so I've uploaded a Monticello-nice.667
> with the hack, and triggered its download in update-eem.406.mcm
> Not sure if it is really necessary...
>
> Now the update is still failing with an emergency evalutator, and this
> time it seems to be related to the progress bar with an obsolete block
> still pointing to MethodContext.
>
> ...snip...
> UndefinedObject>>handleSignal:
> Context(nil)>>handleSignal:
> Context(nil)>>handleSignal:
> Context(nil)>>handleSignal:
> Context(nil)>>handleSignal:
>
> I will retry with Bert's hack.
> This update hickup is a tough one.
>

And Bert's hack is not enough. So another possibility would be to move
#MethodContext -> Context binding in Undeclared.
Undeclared shouldn't auto-clean as long as obsolete block pointing to
MethodContext are still on the stack.
I'm going to try this.
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