There was some invalid state in the screen here, some areas had
sa->full set even though no screen was maximized, which then caused
a restore from the wrong (empty) area, which then led to spacedata
being empty and a crash.
This fix properly clears the sa->full after restore, and also fixes
existing .blend files in such an invalid state.
Only the camera from View3D.localvd is used,
other pointers may be invalid.
Longer term we should probably clear these to ensure no accidents.
For now just follow the rest of Blender's code and don't access.
For example, if you have two keyframes:
k1 = 1px, k2 = 10px
it was doing:
1px, 9px, 8px, ..., 3px, 2px, 10px
instead of:
1px, 2px, 3px, ..., 8px, 9px, 10px
Mostly internal changes, keeping both manipulators
could have worked but there was no point long term.
There are still some glitches to resolve, will work on those next.
This affects the curve display color setting, but is really intended
for future per-curve options.
The id_data reference in the created rna pointers refers to the object
even if the curve is actually owned by its action, which is somewhat
inconsistent, but the same problem can be found in existing code.
Fixing it requires changes in animdata filter API.
Adding alongside the existing one for now,
but it should eventually replace it.
Uses a matrix instead of (position + scale),
written so rotation can be done more easily.
Currently has a primitive handle for rotation, supports corner scaling.
Previously it was returning short, which was really easy to (a) compare against
non-ID type value (b) forget to handle some specific value in switch statement.
Both issues happened in the nearest past, so it's time to tighten some nuts
here.
Most of the change related on silencing strict compiler warning now, but there
is also one tricky aspect: ID_NLA is not in the IDType enum. So there is still
cast to short to handle that switch. If someone has better ideas how to deal
with this please go ahead :)
