Sweep Advance getting called on Non-Dynamic bodies

[2chivi]

This pertains to this function in planck.js: Solver.prototype.solveWorldTOI

I've spent that past few days hunting down a rare desync bug with my multiplayer game. I isolated the problem to my static terrain bodies being very slightly altered by dynamic bodies. By very slightly, I mean m_sweep being altered by very small float rounding errors. But eventually they compound and cause desync issues.

These small rounding errors are caused because Body.prototype.advance or Sweep.prototype.advance getting called on Static objects in Solver.prototype.solveWorldTOI. I don't believe there is a reason for sweep advance to get called on Static objects? I might be wrong. I'm not* super familiar with how this engines works.

I'm not sure I could write a good demo to show off the problem.. but I figured I would altease raise the issue. I've been able to solve the issue by putting !isStatic() checks before each sweep.advance call in Solver.prototype.solveWorldTOI.

(I've never done a bug fix pr, trying to figure it out)