With the r2413 commit that fixed issues with imagery being clipped to the wrong window area, this has exposed some issues with general rendering - manifesting itself sometimes as parts of imagery getting clipped incorrectly and other times as single pixel gaps where imagery is intended to butt together.
Note this issues are really in addition to those already mentioned in the commit log: FIX: Resolve issues where a Window's content was being clipped to it's parent window area(s) instead of it's own. Note the following additional issues this fix exposes: 1) The 'clipped' attribute / setting for StateImagery in Falagard is broken and currently has no effect (this is due to clipping being done at GeometryBuffer level). This issue is best demonstrated by the clipping now done on dragged list header segments. 2) Some layouts / falagard compound widgets have visible clipping artefacts: TextDemo's layout needs a couple of tweaks, and the WidgetLooks for TabControl (at least) have a couple of issues where component widgets do not join together correctly.
Although point 2) does seem to cover the 'gaps' problem.
Additional information: This seems fairly renderer dependent, though is reproducible on all with some effort.
Ogre shows the issues immediately. The GL renderer also shows the issues though sometimes needs a little coaxing - maximising the demo window can usually get you some 'gaps'.
Seems likely to be some kind of pixel alignment issue with clipping area rects used to set up the scissoring area.