[MacRuby-devel] [MacRuby] #723: nsset + bindings error

[MacRuby]

#723: nsset + bindings error
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 Reporter:  jakub.suder@…          |       Owner:  lsansonetti@…        
     Type:  defect                 |      Status:  new                  
 Priority:  major                  |   Milestone:                       
Component:  MacRuby                |    Keywords:                       
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Description changed by martinlagardette@…:

Old description:

> I have a weird error related to NSSet.setWithObjects method and bindings.
> I'm not sure exactly what causes it, but my guess is that it's some kind
> of problem with methods that accept variable number of arguments, that
> only appears in some specific conditions. It took me a few hours to
> isolate only the relevant code, but I managed to cut it down to two small
> classes where changing anything else makes the error disappear (see
> attached zip with a project).
>
> So I have a model class with 3 fields and 2 helper methods using those
> fields. For those 2 helper methods, I provide KVO methods
> keyPathsForValuesAffecting*** returning sets. In the app delegate, I
> create one instance of that class and 2 views, and bind two properties of
> the views to the methods in the model object.
>
> When I get to NSSet.setWithObjects("sender", "recipient", nil) in
> keyPathsForValuesAffectingSenderAndRecipient, the application hangs.
>
> Now, if I change anything in this code, it stops hanging; for example:
> - if I use NSSet.setWithArray(["sender", "recipient"]), it works
> - if I use a set with just "sender" (NSSet.setWithObjects("sender",
> nil)), it works
> - if I delete the second KVO method
> (keyPathsForValuesAffectingHasPicture), the first one starts working
> - if I don't bind the first view to keyPathsForValuesAffectingHasPicture,
> or change the order of bindings, it starts working
> - if I return a 2-element set in keyPathsForValuesAffectingHasPicture, it
> starts working (?!)
> - and here's the funniest one: if I copy the line
> NSSet.setWithObjects("sender", "recipient", nil) to application delegate,
> before the bindings, it works there, and the original invocation inside
> keyPathsForValuesAffectingSenderAndRecipient also magically starts
> working (?!?!)
>
> As you can see, it's hard to figure out what's going on here... But as
> far as I can tell, this smells to me like some kind of bug related to
> memory, pointers pointing to wrong places and so on... (oh, good old C
> times... :)
>
> And BTW, if I rewrite the model class (Message) in ObjC, it also starts
> working.
>
> Tested on MacRuby 0.6.

New description:

 I have a weird error related to `NSSet.setWithObjects` method and
 bindings. I'm not sure exactly what causes it, but my guess is that it's
 some kind of problem with methods that accept variable number of
 arguments, that only appears in some specific conditions. It took me a few
 hours to isolate only the relevant code, but I managed to cut it down to
 two small classes where changing anything else makes the error disappear
 (see attached zip with a project).

 So I have a model class with 3 fields and 2 helper methods using those
 fields. For those 2 helper methods, I provide KVO methods
 `keyPathsForValuesAffecting***` returning sets. In the app delegate, I
 create one instance of that class and 2 views, and bind two properties of
 the views to the methods in the model object.

 When I get to `NSSet.setWithObjects("sender", "recipient", nil)` in
 `keyPathsForValuesAffectingSenderAndRecipient`, the application hangs.

 Now, if I change anything in this code, it stops hanging; for example:
  * if I use `NSSet.setWithArray(["sender", "recipient"])`, it works
  * if I use a set with just "`sender`" (`NSSet.setWithObjects("sender",
 nil)`), it works
  * if I delete the second KVO method
 (`keyPathsForValuesAffectingHasPicture`), the first one starts working
  * if I don't bind the first view to
 `keyPathsForValuesAffectingHasPicture`, or change the order of bindings,
 it starts working
  * if I return a 2-element set in `keyPathsForValuesAffectingHasPicture`,
 it starts working (?!)
  * and here's the funniest one: if I copy the line
 `NSSet.setWithObjects("sender", "recipient", nil)` to application
 delegate, before the bindings, it works there, and the original invocation
 inside `keyPathsForValuesAffectingSenderAndRecipient` also magically
 starts working (?!?!)

 As you can see, it's hard to figure out what's going on here... But as far
 as I can tell, this smells to me like some kind of bug related to memory,
 pointers pointing to wrong places and so on... (oh, good old C times... :)

 And BTW, if I rewrite the model class (Message) in ObjC, it also starts
 working.

 Tested on MacRuby 0.6.

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Ticket URL: <http://www.macruby.org/trac/ticket/723#comment:1>
MacRuby <http://macruby.org/>