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: lmem.h,v 1.31.1.1 2007/12/27 13:02:25 roberto Exp $
** Interface to Memory Manager
** See Copyright Notice in lua.h
*/
#ifndef lmem_h
#define lmem_h
#include <stddef.h>
#include "llimits.h"
#include "lua.h"
#define MEMERRMSG "not enough memory"
#define luaM_reallocv(L,b,on,n,e) \
((cast(size_t, (n)+1) <= MAX_SIZET/(e)) ? /* +1 to avoid warnings */ \
luaM_realloc_(L, (b), (on)*(e), (n)*(e)) : \
luaM_toobig(L))
#define luaM_freemem(L, b, s) luaM_realloc_(L, (b), (s), 0)
#define luaM_free(L, b) luaM_realloc_(L, (b), sizeof(*(b)), 0)
#define luaM_freearray(L, b, n, t) luaM_reallocv(L, (b), n, 0, sizeof(t))
#define luaM_malloc(L,t) luaM_realloc_(L, NULL, 0, (t))
#define luaM_new(L,t) cast(t *, luaM_malloc(L, sizeof(t)))
#define luaM_newvector(L,n,t) \
cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
#define luaM_growvector(L,v,nelems,size,t,limit,e) \
if ((nelems)+1 > (size)) \
((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
#define luaM_reallocvector(L, v,oldn,n,t) \
((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
size_t size);
LUAI_FUNC void *luaM_toobig (lua_State *L);
LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
size_t size_elem, int limit,
const char *errormsg);
#endif