Glyph Atlas isn't cleaned up properly

[kkaefer]

[mikemorris]

Possible this is causing https://github.com/mapbox/node-mapbox-gl-native/issues/106 as well?

[friedbunny]

#3781 should improve this. The CJK glyph corruption in #1681 is likely caused by this issue.

[jfirebaugh]

Should be fixed by #8341.

[ChrisLoer]

Are we just hoping #8341 will fix this by shaking things up? There's a new implementation, but the tile reference counting scheme is still essentially the same.

[jfirebaugh]

I think we should check if this issue still exists after #8341 lands. It shakes things up enough that it seems like there's a pretty good chance any remaining issue would in fact be an issue in #8341 itself.

[ChrisLoer]

Do we have a test protocol that exposes this behavior? #8341 is in now, so this is speculatively fixed. As a simple test, I loaded a bunch of chinese tiles with the glyph atlas debug view, watched the atlas fill up with Chinese glyphs, then panned over to France, zoomed in, and watched them all get cleaned out as the tiles got pushed out of the cache. However, that's the same behavior I saw before my changes, so I'm not sure it's a useful test.

[jfirebaugh]

In that case the bug was very likely already fixed at some point. We're pretty confident in the code now and it seems to be working, so I think this can be closed.

[kkaefer]

It's also possible that when I originally filed the bug, Mapbox GL was still retaining tiles in the cache, so this never really was a bug to begin with.