+ /* The new base name is long enough to require a pathconf check. */
+ long name_max;
+ errno = 0;
+ if (s == filename)
+ name_max = pathconf (".", _PC_NAME_MAX);
+ else
+ {
+ char c = *s;
+ if (! ISSLASH (c))
+ *s = 0;
+ name_max = pathconf (filename, _PC_NAME_MAX);
+ *s = c;
+ }
+ if (0 <= name_max || errno == 0)
+ slen_max = name_max == (size_t) name_max ? name_max : -1;