[Libguestfs] [PATCH nbdkit] server/public.c: Uninline nbdkit_strdup_intern to avoid compiler warning.

[Richard W.M. Jones]

A simple reproducer is:

----------------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

const char *
copyn (const char *str, size_t n)
{
  return strndup (str, n);
}

const char *
copy (const char *str)
{
  return copyn (str, SIZE_MAX);
}
----------------------------------------------------------------------

$ gcc -O2 -Wall -c test.c
In function ‘copyn’,
    inlined from ‘copy’ at test.c:15:10:
test.c:9:10: warning: ‘strndup’ specified bound 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
    9 |   return strndup (str, n);
      |          ^~~~~~~~~~~~~~~~

$ gcc --version
gcc (GCC) 10.2.1 20200826 (Red Hat 10.2.1-3)
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

I'm still not clear if this is a GCC problem or a code problem,
although Dan pointed out on the list that SIZE_MAX is the largest
size_t, so I guess our code seems OK ...

Rich.

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