Re: issue following array example in pil chapter 28.2

[David Rio <driodeiros@...>]

Tet me try to simplify the amount of code necessary to reproduce
the issue:

--------------------$ cat compile.sh
#!/bin/bash
rm -f *.o *.so
gcc -g -c ldrdlib.c
gcc -g -Wall -shared  -llua -o mylib.so ldrdlib.o

-------------------$  cat ldrdlib.c
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"

static int l_sin (lua_State *L) {
  double d = luaL_checknumber(L, 1);
  lua_pushnumber(L, sin(d));
  return 1;  /* number of results */
}

static const struct luaL_reg mylib [] = {
  {"l_sin", l_sin},
  {NULL, NULL}  /* sentinel */
};

int luaopen_mylib (lua_State *L) {
  luaL_newmetatable(L, "LuaBook.array"); // THis is the line that breaks
  luaL_openlib(L, "mylib", mylib, 0);
  return 1;
}

-----------------$ cat play.lua
#!/usr/bin/env lua

require 'mylib'
print(mylib.l_sin(0.5))

And here is how I run it and the error:

$ ./compile.sh && ./lua-5.1.4/src/lua play.lua
0.4794255386042
lua(88449) malloc: *** error for object 0x102f22380: pointer being
freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6

This error pops up when I introduce this line of code in the c library
to create a new table:

 luaL_newmetatable(L, "LuaBook.array");

Thanks,
-drd