[Laszlo-dev] For Review: Change 20090508-bargull-QAO Summary: animator bug due to implicit coercion

[P T Withington]

Approved!

But maybe we also ought to file a feature request that if you don't  
give an animator an attribute to animate, it shouldn't try to animate  
the attribute named 'null'?

On 2009-05-08, at 14:24EDT, André Bargull wrote:

> Change 20090508-bargull-QAO by bargull at dell--p4--2-53 on 2009-05-08  
> 20:09:33
> in /home/Admin/src/svn/openlaszlo/trunk
> for http://svn.openlaszlo.org/openlaszlo/trunk
>
> Summary: animator bug due to implicit coercion
>
> New Features:
>
> Bugs Fixed: LPP-8172 ('empty' animators do not run in swf9)
>
> Technical Reviewer: ptw
> QA Reviewer: (pending)
> Doc Reviewer: (pending)
>
> Documentation:
>
> Release Notes:
>
> Details:
> Empty animators caused a subtle bug in swf9 because of implicit  
> coercion in swf9:
> In swf9, 'undefined' can only be used for the any-type ('*'), for  
> any other type 'undefined' is coerced to 'null'. This is a problem  
> if you intend to use strict typing, but then forget some casts. In  
> this case, the "attribute"-property was casted to String in some  
> methods, but in several methods it wasn't. And if you later use  
> string concatenation (here: "e_" + attribute), you may get  
> "e_null" (coerced) or "e_undefined" (not coerced).
>
>
>
> Tests:
> testcase from bugreport
>
> Files:
> M WEB-INF/lps/lfc/controllers/LaszloAnimation.lzs
>
> Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20090508-bargull-QAO.tar
>