Player can get stuck on supposedly walkable tiles

[zorfmorf]

The overlay bug has probably nothing to do with it

[zorfmorf]

Can be reproduced in any direction near a row of non walkable tiles. Walking alongside of it and trying to walk into each blocked tile will sooner or later allow the player to move slightly into the tile and then be stuck

[zorfmorf]

Found the problem! Out of lazyness, at one code point the pos table (actual tile position) was assigned to the posd table (draw position, can be between tiles), so when posd.x or pos.y tile was modified, the actual tile position was modified as well and therefore could have non-integer values which broke movement completely.