[Etoys] Screen damage issues when dropping tiles in ScriptEditor

[karl]

Yoshiki Ohshima skrev:
>> When I turn on preference showDebugDamage there are some
>> issues when dropping tiles in the ScriptEditor. A rectangle in the
>> top left corner flashes, and a large part of the screen is redrawn when
>> the tile is dropped, from top left of screen to bottom right of 
>> ScriptEditor.
>> I guess this will slow the tile scripting responsiveness.
>> Also the Viewer flap tabs are redrawn quite often, not flap tabs for 
>> SketchMorphs, but for other morphs.
>> Karl
>>     
>
>   Thanks Karl for reporting!  We did use showDebugDamage when damage
> rectangle merging was too eagar^^; But after that we didn't look at
> other places with the option turn on yet.
I did some bug hunting on the ScriptEditorMorph redraw bug and it is 
really hard to track down, at least for me :-)
It seems the bug is related to a bug in Squeak3.9 when SystemBrowsers 
causes extensive redrawing when the comment pane pops up and hides. 
I have looked at Morph>>privateAddMorph:atIndex: and a few layout 
related methods but have not found the cause yet.
Karl