Openrct2: Scenario list glitches when you have too many scenarios

[LordMarcel]

OS: Windows 10
Version: 0.2.6
Commit/Build: bb1d814

If you have too many scenarios in your scenario list they become invisible once you scroll down far enough. It seems to happen after about 1350 scenarios. You can still select the scenarios and play them without any issues. When I tried adding enough scenarios to cause this issue in vanilla I lost the ability to scroll down at all so I don't know if this happens in vanilla too.

Screenshot:

[James103]

There's most likely a 16-bit overflow somewhere in the drawing code, since 1350 * 24 = 32400 pixels, which is very close to 32767.