Add a copy of aper_get_nsnnwn() and aper_put_nsnnwn() to per_support.c, just in case.

They're disabled by default, but can be turned on by defining USE_OLDER_APER_NSNNWN.
The main difference is - these do not use "range" argument, but receive it as dummy.

skeletons/per_support.c

@@ -369,6 +369,7 @@ aper_get_nslength(asn_per_data_t *pd) {
 	}
 }
 
+#if !defined(USE_OLDER_APER_NSNNWN)
 ssize_t
 aper_get_nsnnwn(asn_per_data_t *pd, int range) {
 	ssize_t value;
@@ -402,6 +403,31 @@ aper_get_nsnnwn(asn_per_data_t *pd, int range) {
 	value = per_get_few_bits(pd, 8 * bytes);
 	return value;
 }
+#else /* old APER codec */
+ssize_t
+aper_get_nsnnwn(asn_per_data_t *pd, int dummy_range) {
+       ssize_t value;
+
+       ASN_DEBUG("Get the normally small non-negative whole number APER");
+
+       value = per_get_few_bits(pd, 7);
+       if(value & 64) {        /* implicit (value < 0) */
+               value &= 63;
+               value <<= 2;
+               value |= per_get_few_bits(pd, 2);
+               if(value & 128) /* implicit (value < 0) */
+                       return -1;
+               if(value == 0)
+                       return 0;
+               if(value >= 3)
+                       return -1;
+               value = per_get_few_bits(pd, 8 * value);
+               return value;
+       }
+
+       return value;
+}
+#endif /* don't use old APER */
 
 int aper_put_align(asn_per_outp_t *po) {
 
@@ -458,6 +484,7 @@ aper_put_nslength(asn_per_outp_t *po, size_t length) {
 	return 0;
 }
 
+#if !defined(USE_OLDER_APER_NSNNWN)
 int
 aper_put_nsnnwn(asn_per_outp_t *po, int range, int number) {
 	int bytes;
@@ -503,3 +530,28 @@ aper_put_nsnnwn(asn_per_outp_t *po, int range, int number) {
 */
     return per_put_few_bits(po, number, 8 * bytes);
 }
+#else /* preserve old code base in case */
+int
+aper_put_nsnnwn(asn_per_outp_t *po, int dummy_range, int n) {
+       int bytes;
+
+       ASN_DEBUG("aper_put_nsnnwn");
+
+       if(n <= 63) {
+               if(n < 0) return -1;
+               return per_put_few_bits(po, n, 7);
+       }
+       if(n < 256)
+               bytes = 1;
+       else if(n < 65536)
+               bytes = 2;
+       else if(n < 256 * 65536)
+               bytes = 3;
+       else
+               return -1;      /* This is not a "normally small" value */
+       if(per_put_few_bits(po, bytes, 8))
+               return -1;
+
+       return per_put_few_bits(po, n, 8 * bytes);
+}
+#endif /* which aper_put_nsnnwn() */