[PATCH v2 1/2] timezone: sync to tzdb 2026b

[Florian Weimer]

* Adhemerval Zanella Netto:

> On 19/05/26 09:04, Joseph Myers wrote:
>> On Fri, 15 May 2026, Adhemerval Zanella Netto wrote:
>> 
>>>> +#ifndef HAVE_MEMPCPY
>>>> +# if (defined mempcpy \
>>>> +      || defined __FreeBSD__ || defined __NetBSD__ || defined __linux__)
>
> Maye use __GLIBC__ and something for musl instead?

I think musl still strives to be difficult to identify.

>>>> +#  define HAVE_MEMPCPY 1
>>>> +# else
>>>> +#  define HAVE_MEMPCPY 0
>>>> +# endif
>>>> +#endif
>>>> +#if !HAVE_MEMPCPY
>>>> +static void *
>>>> +mempcpy(void *restrict s1, void const *restrict s2, size_t n)
>>>> +{
>>>> +  char *p = memcpy(s1, s2, n);
>>>> +  return p + n;
>>>> +}
>>>> +#endif

We already have this in include/libc-symbols.h:

/* Define these macros for the benefit of portable GNU code that wants to check
   them.  Of course, STDC_HEADERS is never false when building libc!  */
#define STDC_HEADERS    1
#define HAVE_MBSTATE_T  1
#define HAVE_MBSRTOWCS  1
#define HAVE_LIBINTL_H  1
#define HAVE_WCTYPE_H   1
#define HAVE_ISWCTYPE   1
#define ENABLE_NLS      1

I think it would make sense to expand that.