if (strlen (buf) != words * 4 + lens[last])
if (strlen (buf) != words * 4 + lens[last] || strnlen (buf, -1) != words * 4 + lens[last])
main(int argc, char *argv[]){  static const size_t lens[] = { 0, 1, 0, 2, 0, 1, 0, 3,				 0, 1, 0, 2, 0, 1, 0, 4 };  char basebuf[24 + 32];  size_t base;  for (base = 0; base < 32; ++base)    {      char *buf = basebuf + base;      size_t words;      for (words = 0; words < 4; ++words)	{	  size_t last;	  memset (buf, 'a', words * 4);	  for (last = 0; last < 16; ++last)	    {	      buf[words * 4 + 0] = (last & 1) != 0 ? 'b' : '\0';	      buf[words * 4 + 1] = (last & 2) != 0 ? 'c' : '\0';	      buf[words * 4 + 2] = (last & 4) != 0 ? 'd' : '\0';	      buf[words * 4 + 3] = (last & 8) != 0 ? 'e' : '\0';	      buf[words * 4 + 4] = '\0';	      if (strlen (buf) != words * 4 + lens[last])		{		  printf ("failed for base=%Zu, words=%Zu, and last=%Zu\n",			  base, words, last);		  return 1;		}	    }	}    }  return 0;}