Roads overlay buildings at top left edge

[GunChleoc]

When the view is scrolled so that a building ends up partially outside of the top left corner of the screen, the road is blitted on top of the building.

[SirVer (sirver)]

The problem seems a bit more involved. In this video: https://youtu.be/L6da7_ZfugM, I found a spot where going 10 pixels left or right toggles the wrong rendering, as well as going 10 pixels up and down. If the view is scrolled further right, the bug cannot be triggered anymore.

This leads me to believe that this is related to map wrap-around.

The video is made with the attached savegame.

[SirVer (sirver)]

Scratch that - there is no map wrap close by in the attached savegame and the bug is still triggered. I do not get it though, the RoadProgram is always drawn with a smaller z value, it should never be drawn over objects which are drawn later, i.e. with a larger z-value.

No idea right now.

[GunChleoc (gunchleoc)]

Migrated to https://github.com/widelands/widelands/issues/1654