Re: segmentation fault in luaG_findlocal

[Francisco Olarte <folarte@...>]

On Fri, 1 Sept 2023 at 15:50, Sergey Bronnikov <sergeyb@tarantool.org> wrote:

>   lua_Debug ar;
>   lua_getlocal(L, &ar, 100);

I think you are accessing uninitialized memory:

>>>>
const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);

Gets information about a local variable or a temporary value of a
given activation record or a given function.

In the first case, the parameter ar must be a valid activation record
that was filled by a previous call to lua_getstack or given as
argument to a hook (see lua_Hook). The index n selects which local
variable to inspect; see debug.getlocal for details about variable
indices and names.

lua_getlocal pushes the variable's value onto the stack and returns its name.

In the second case, ar must be NULL and the function to be inspected
must be on the top of the stack. In this case, only parameters of Lua
functions are visible (as there is no information about what variables
are active) and no values are pushed onto the stack.

Returns NULL (and pushes nothing) when the index is greater than the
number of active local variables.
<<<<
Francisco Olarte.