Loss of interpolation while changing player ang/horiz from CON

If you change the beginning of the APLAYER definition in Duke3D v1.5's GAME.CON file as described here, pressing on the "use" key should shift the player's ang and horiz fields.

With EDuke 2.0 and EDuke32-OldMP, this is working as expected, while with mainline EDuke32, this works without interpolation. The loss of interpolation was introduced in SVN r8551: d8a523e5

SVN r8552 is probably the better candidate for testing instead: 16fc20a5

gamevar MYNEWTEMP 0 1 // TEST VAR
actor APLAYER MAXPLAYERHEALTH PSTAND 0 0
  // TEST BEGIN
  ifhitspace
  {
    getplayer[THISACTOR].horiz MYNEWTEMP
    addvar MYNEWTEMP -8
    setplayer[THISACTOR].horiz MYNEWTEMP
    getplayer[THISACTOR].ang MYNEWTEMP
    addvar MYNEWTEMP 8
    setplayer[THISACTOR].ang MYNEWTEMP
  }
  // TEST END