Re: c-strtod: improve error checking

[Jim Meyering]

Bruno Haible <address@hidden> wrote:
> Here's a proposed patch to improve c_strtod's error checking:
> 1) It currently does not check against a NULL return from newlocale(),
>    which can happen for example if out of memory.
> 2) When strtod_l or strtod returns an error, c_strtod fails to preserve
>    errno as an error indicator.

Thanks for the fixes.

> 2009-01-21  Bruno Haible  <address@hidden>
>
>       * lib/c-strtod.c: Include errno.h.
>       (C_STRTOD): Check against NULL return from newlocale. Preserve errno
>       value from STRTOD_L and STRTOD.
>
> --- lib/c-strtod.c.orig       2009-01-21 12:15:31.000000000 +0100
> +++ lib/c-strtod.c    2009-01-21 12:15:24.000000000 +0100
> @@ -1,6 +1,6 @@
>  /* Convert string to double, using the C locale.
>
> -   Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
> +   Copyright (C) 2003, 2004, 2006, 2009 Free Software Foundation, Inc.
>
>     This program is free software: you can redistribute it and/or modify
>     it under the terms of the GNU General Public License as published by
> @@ -21,6 +21,7 @@
>
>  #include "c-strtod.h"
>
> +#include <errno.h>
>  #include <locale.h>
>  #include <stdlib.h>
>
> @@ -50,9 +51,18 @@
>
>  #ifdef LC_ALL_MASK
>
> -  locale_t c_locale = newlocale (LC_ALL_MASK, "C", 0);
> +  locale_t c_locale;
> +  int saved_errno;
> +
> +  c_locale = newlocale (LC_ALL_MASK, "C", (locale_t)0);

I suppose NULL isn't necessarily defined, so ok to add the cast.
But please insert a space between the cast and the "0": (locale_t) 0.

> +  if (c_locale == (locale_t)0)

I prefer to avoid casts, so please use this test instead:

     if (!c_locale)