Re: Slight oddity with os.date("")

[roberto@... (Roberto Ierusalimschy)]

> In Lua 5.1, when you call os.date with an empty format string, you get
> the somewhat unexpected error "'date' format too long" :-)
> 
> This is because the implementation checks the return value from the C
> function strftime() which is 0 both when there is an error and when
> the format string is empty.
> 
> This is not critical, but one would expect os.date to return the empty
> string when the format is empty (just like string.format). A possible
> fix would be:
> 
> --- loslib.c
> +++ loslib.c
> @@ -145,6 +145,8 @@
>     setfield(L, "yday", stm->tm_yday+1);
>     setboolfield(L, "isdst", stm->tm_isdst);
>   }
> +  else if (*s == '\0')
> +    lua_pushstring(L, "");
>   else {
>     char b[256];
>     if (strftime(b, sizeof(b), s, stm))

You are right about the problem. But your fix does not fix it :(
Non-empty format strings may also correctly result in the empty string
(e.g., "%p" or "%z" in some locales).

-- Roberto