Nice!  Turning off that preference has been broken forever...

On Tue, May 17, 2016 at 7:24 AM,  <commits at source.squeak.org> wrote:
> Marcel Taeumel uploaded a new version of System to project The Trunk:
> http://source.squeak.org/trunk/System-mt.830.mcz
>
> ==================== Summary ====================
>
> Name: System-mt.830
> Author: mt
> Time: 17 May 2016, 2:24:39.256089 pm
> UUID: 7cf55fb7-9e1f-5c45-baf8-eb29fcf2ac91
> Ancestors: System-mt.829
>
> Fixes a bug where space was reserved for flaps when positioning windows although no flaps were visible at all.
>
> Now, the preference #fullScreenLeavesDeskMargins works as expected.
>
> =============== Diff against System-mt.829 ===============
>
> Item was changed:
>   ----- Method: RealEstateAgent class>>maximumUsableAreaInWorld: (in category 'accessing') -----
>   maximumUsableAreaInWorld: aWorldOrNil
>
>         | allowedArea |
>         allowedArea := Display usableArea.
>         aWorldOrNil ifNotNil: [
>                 allowedArea := allowedArea intersect: aWorldOrNil visibleClearArea.
> +               Smalltalk isMorphic ifTrue: [
> +                       (((Smalltalk classNamed: 'Flaps') ifNil: [false] ifNotNil: [:cls | cls anyFlapsVisibleIn: aWorldOrNil])
> +                               and: [self respondsTo: #reduceByFlaps:])
> +                                       ifTrue: [allowedArea := self reduceByFlaps: allowedArea]]].
> -       ].
> -       (Smalltalk isMorphic and: [self respondsTo: #reduceByFlaps:]) ifTrue:
> -               [allowedArea := self reduceByFlaps: allowedArea].
>         ^allowedArea!
>
>