Status line disappears in Advent.z5 about ifvms.js

[erkyrath]

After digging into various interpreters, here's what I find:

We have a de-facto rule that if you call set_cursor with a nonexistent row number, the status window height increases to allow that row to exist. Fizmo, GarGlk+Frotz, and the old Parchment both do this. The I6 library apparently relies on this behavior.

My patch adds the appropriate test to set_cursor, but it also required a couple of other changes. In set_window, I moved the glk_set_window() and format() calls to after the set_cursor call -- before that call, upperwin may not exist yet. I also added a this.io.height = 0 in one spot in split_window where it was missing.

With this change, Advent.z5 and Curses.z5 both handle their status lines correctly.

(Except that the Curses.z5 quote boxes still don't work. That will require special-case logic -- you've seen my notes on the subject.)

[erkyrath]

(I went ahead and pushed this change out in a Lectrote release, which was presumptuous, but I'm pretty sure it's correct.)

[curiousdannii]

When I wrote the windowing code from scratch using Glk I decided to stick to only what the standard said, and to only add support for non-standard behaviour once there were clear examples of it, because I couldn't remember which story files exactly needed what, and whether all that was supported actually needed to be.

Thanks for the diagnosis and the patch!

[curiousdannii]

I've also given you commit access to the repository if you'd prefer to commit directly instead of making PRs.

[erkyrath]

Thanks. I'll still do PRs, in general, so you can look stuff over.