Comment 26 for bug 1818494

It is still there - I added the assert that was triggered in #20 with my other fixes related to this branch. So, that assert could never have been triggered with an older version.

The crash happens because the dimension of the viewport to show goes negative. It does not seem to be a simple int overflow though, because I can run it even at higher resolutions without a problem.

If we can't figure this out soon, we can hack it for Build 20 and simply skip the rest of the function if the dimension goes negative, but I'd rather have a real fix.