lua_setfield, lua_getfield and valid stack index

[Shmuel Zeigerman <shmuz@...>]

The Manual says:
(1)
> We say that an index is valid if it lies between 1 and the stack top
> (that is, if 1 ? abs(index) ? top).

(2)
> void lua_setfield (lua_State *L, int index, const char *k);
>
> Does the equivalent to t[k] = v, where t is the value at the given
> valid index index and v is the value at the top of the stack,

It follows from (1) and (2) that

    lua_setfield(L, LUA_REGISTRYINDEX, "some field")

is incorrect, because LUA_REGISTRYINDEX is not a valid index.

Is it so, or the Manual should be corrected?

--
Shmuel