This map has always been broken. This variant makes it slightly less broken (although something changed on the ceiling might prevent hiding on pixels on the slope). What will finally fix it is either moving nets closer together or adding angle bounce to hedgehogs or some other layout that prevents hiding.
/*
** $Id: lfunc.h,v 2.4.1.1 2007/12/27 13:02:25 roberto Exp $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
#ifndef lfunc_h
#define lfunc_h
#include "lobject.h"
#define sizeCclosure(n) (cast(int, sizeof(CClosure)) + \
cast(int, sizeof(TValue)*((n)-1)))
#define sizeLclosure(n) (cast(int, sizeof(LClosure)) + \
cast(int, sizeof(TValue *)*((n)-1)))
LUAI_FUNC Proto *luaF_newproto (lua_State *L);
LUAI_FUNC Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e);
LUAI_FUNC Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e);
LUAI_FUNC UpVal *luaF_newupval (lua_State *L);
LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
LUAI_FUNC void luaF_close (lua_State *L, StkId level);
LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
LUAI_FUNC void luaF_freeclosure (lua_State *L, Closure *c);
LUAI_FUNC void luaF_freeupval (lua_State *L, UpVal *uv);
LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
int pc);
#endif