Re: Possible debug.debug bug

[Roberto Ierusalimschy <roberto@...>]

> db_debug has these lines:
> 
>     if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
>         lua_pcall(L, 0, 0, 0))
>       lua_writestringerror("%s\n", lua_tostring(L, -1));
> 
> lua_writestringerror is defined as:
> 
> #define lua_writestringerror(s,p) \
>         (fprintf(stderr, (s), (p)), fflush(stderr))
> 
> lua_tostring may return NULL if the error object that lua_pcall pushes onto the
> stack is not a string. In this case NULL is passed to fprintf, which is
> undefined behavior.

Thanks for the report.

-- Roberto