- Closes https://github.com/ppy/osu/issues/31423.
- Regressed in https://github.com/ppy/osu/pull/30411.
Admittedly, I don't completely understand all of the pieces here,
because code quality of this placement blueprint code is ALL-CAPS
ATROCIOUS, but I believe the failure mode to be something along the
lines of:
- User activates juice stream tool, blueprint gets created in initial
state. It reads in a mouse position far outside of the playfield, and
sets internal positioning appropriately.
- When the user moves the mouse into the bounds of the playfield, some
positions update (the ones inside `UpdateTimeAndPosition()`, but the
fruit markers are for *nested* objects, and
`updateHitObjectFromPath()` is responsible for updating those...
however, it only fires if the `editablePath.PathId` changes, which it
won't here, because there is only one path vertex until the user
commits the starting point of the juice stream and it's always at
(0,0).
- Therefore the position of the starting fruit marker remains bogus
until left click, at which point the path changes and everything
returns to *relative* sanity.
The solution essentially relies on inlining the broken method and only
guarding the relevant part of processing behind the path version check
(which is actually updating the path). Everything else that can touch
positions of nesteds (like default application, and the drawable piece
updates) is allowed to happen unconditionally.
Until now, these were haphazardly enforce inline in blueprint
implementations. The only thing stopping complete breakage is that
`EndPlacement` wasn't called (too much) from outside the blueprint,
leaving them responsible for their own placement.
By moving this conditional out of the provided paramters to
`EndPlacement`, it allows more flexible usage of that method externally.
Coming in a future PR.
