0-length strings are ok

src/lib/ares__buf.c

@@ -796,16 +796,17 @@ ares_status_t ares__buf_parse_dns_binstr(ares__buf_t *buf, size_t remaining_len,
       break;
     }
 
+    if (len) {
       /* XXX: Maybe we should scan to make sure it is printable? */
       if (bin != NULL) {
         status = ares__buf_fetch_bytes_into_buf(buf, binbuf, len);
       } else {
         status = ares__buf_consume(buf, len);
       }
-
       if (status != ARES_SUCCESS) {
         break;
       }
+    }
 
     if (!allow_multiple) {
       break;

src/lib/ares_dns_parse.c

@@ -261,9 +261,11 @@ static ares_status_t ares_dns_parse_rr_hinfo(ares__buf_t   *buf,
   }
 
   /* OS */
-  return ares_dns_parse_and_set_dns_str(
+  status = ares_dns_parse_and_set_dns_str(
     buf, ares_dns_rr_remaining_len(buf, orig_len, rdlength), ARES_FALSE, rr,
     ARES_RR_HINFO_OS);
+
+  return status;
 }
 
 static ares_status_t ares_dns_parse_rr_mx(ares__buf_t *buf, ares_dns_rr_t *rr,
@@ -1085,7 +1087,6 @@ static ares_status_t ares_dns_parse_rr(ares__buf_t *buf, unsigned int flags,
     goto done;
   }
 
-
   /* Determine how many bytes were processed */
   processed_len = remaining_len - ares__buf_len(buf);