Issues was again the ugly hack of swapping last generated tri with original face
we use in BMesh triangulate code - here it could lead in some rare case to have
invalid face pointer in doubles list.
Existing collapse functions were strict regarding the number of verts sharing an edge.
BM_edge_collapse allows any edge to be passed in without first having to manipulate geometry.
Custom-data on newly created face data was often rotated.
Now the API doesn't copy data from adjacent loops when creating faces.
Most functions were already overwriting this anyway.
Since such decisions are better made at a higher level, now it's the responsibility of the caller.
Fix for T46494 wasn't working properly when de-selecting faces,
adjacent faces would remain selected but have unselected edges.
Logic here is admittedly rather fragile since it relies on both
selection functions and flushing afterwards.
This causes no change in behavior, since code was alreadying doing
a no-op in bmesh_edge_separate if the edge is a boundary.
But it tripped an assert, annoying in debug builds.
We want to leave assert in bmesh_edge_separate in case callers
expect there to be separate loops after this always.
So putting test in caller.
(Same worry about bmesh_urmv_loop? I checked callers and they
appear OK to me - they deal with the no-op return.)
- Add blentranslation `BLT_*` module.
- moved & split `BLF_translation.h` into (`BLT_translation.h`, `BLT_lang.h`).
- moved `BLF_*_unifont` functions from `blf_translation.c` to new source file `blf_font_i18n.c`.
Current behavior of bevel is to 'loop slide' along unbeveled edges
when possible, but this produces uneven bevel widths sometimes,
so this option lets user choose between having the loop slide effect
or having more even bevel widths. Trying it out with default being
'no loop slide', so different from current behavior. May reverse this
choice later, depending on user reactions.
