[Lazarus] Patch for simple docking.

[Mattias Gaertner]

On Sun, 4 Apr 2010 13:31:10 +0200 (CEST)
Michael Van Canneyt <michael at freepascal.org> wrote:

> 
> Hello,
> 
> I'm writing an article about docking in Lazarus.
> 
> The first - and most simple - example I tried, failed:
> - Drop a panel on a form
> - Set dragkind to dkDock
> - Set dragmode to dkAutomatic.
> - Run application
> - Drag panel outside form, and let go.
> 
> expected behaviour: a small form should appear, and the panel should be on it.
> 
> Actual behaviour: 4 Access violations (fix one to get to the next ;) ).
> 
> Attached small patch fixes the 4 access violations, after which the expected behaviour 
> occurs. They are all checks to see if a object pointer is not-nil.

Thanks. Applied.

Mattias