[fpc-devel] Sven commit (r34087) breaks casting an object to an interface

[Dimitrios Chr. Ioannidis]

On 15/7/2016 12:51 μμ, Maciej Izak wrote:
> Hi,
>
> change in mentioned FPC trunk r34087 totally breaks sparta 
> dockedformeditor package (and probably many other things) see:
>
> http://forum.lazarus.freepascal.org/index.php/topic,27211.msg216064.html#msg216064
> http://bugs.freepascal.org/view.php?id=30377
>
> please revert mentioned commit (what is sense for such change?).
>
> For example problem exist in sparta_MainIDE.pas module:
>
> === code begin ===
> constructor TDesignFormData.Create(AForm: TCustomForm);
> begin
>   FForm := AForm as IDesignedForm; // won't work anymore. FForm is an 
> interface
> === code end ===

Just looked in the sources a little bit, and I saw that you use 
interface inheritance.

Never used that and searching on the net found the following 
http://stackoverflow.com/questions/14931940/casting-object-to-interface-type-with-no-tinterfacedobject-as-base-class. 


The change is for Delphi compatibility maybe ?

Anyway, this is out of my league ....

regards,
-- 
Dimitrios Chr. Ioannidis