[g3.7.1] Mid-texture clipping issue

[Maniac]

Here's an issue with what appears to be mid textures being (partially) drawn over the upper texture despite clip-mid flagged on. MAP01 of the linked WAD shows the issue and, interestingly enough, MAP02, which is the identical construct with the rest of the map cropped out, doesn't exhibit the issue.

This only appears in the software renderer.

http://maniacsvault.net/dumpster/TEXBUG.WAD

EDIT: Originally posted with version g3.6.0. Issue still appears with version 3.7.1.