Re: luaL_register crashed on iOS

[Roberto Ierusalimschy <roberto@...>]

> It seems like a bug of luaV_settable of version 5.1.4, and works fine under 5.1.5

As lhf said, your code is broken; you should fix it even if it works
under 5.1.5.

The documentation of 'luaL_register' [1] is clear:

  When called with a non-null libname, luaL_register creates a new table t,
  [...]
  In any case the function leaves the table on the top of the stack.

So, you push one new element on the stack at each call to
'luaL_register'. The documentation also says [2]:

  When you interact with Lua API, you are responsible for ensuring
  consistency. In particular, you are responsible for controlling
  stack overflow. [...]

  Whenever Lua calls C, it ensures that at least LUA_MINSTACK stack
  positions are available. LUA_MINSTACK is defined as 20, [...]

As you call 'luaL_register' more than 20 times without popping the
results, you have a stack overflow. Anything that happens after that
is undefined behavior (which means it can even work as expected).

If your corrected code still crashes under 5.1.4, please tell us.


[1] http://www.lua.org/manual/5.1/manual.html#luaL_register
[2] http://www.lua.org/manual/5.1/manual.html#3.2

-- Roberto