orca is hidden behind deltas in intro on kitty selfref

[dankamongmen]

In intro on Kitty with selfref animation (see #1900), once the orca emerges from behind the HUD, she's missing her midsection. This is a regression, pointing to broken rebuilds. Screenshot:

Let's try to get this fixed up before Kitty 0.21.3 drops and triggers this behavior (I'm forcing selfref for the purpose of testing).

[dankamongmen]

yeah, if one runs bitmapstates, when it says "should see full square", we're still seeing asterisks. rebuilds are definitely broken. that's surprising, because statepixel is working properly.

[dankamongmen]

hrmmm, i thought it might be due to the image moving, but that doesn't seem to be the problem...i can have statepixel move all over the place, and things remain alright:

[dankamongmen]

ahhh, i think what's going on is that we're emitting the rebuild into the local mstreamfp. we hit sprite_redraw(), and that's going to prefer kitty_move(), which writes directly to the FILE. we need dump the mstreamfp contents into the FILE beforehand, and that ought get it i think.

[dankamongmen]

this was kovid being sloppy, not our bug =]. verified that things work with his fix during the 0.22.1 development cycle. i'm going to reenable this backend for kitty 0.22.1+.