fix broken iso15693.c:SendRawCommand15693 (double answers)

Author: horrordash

armsrc/iso15693.c

@@ -2729,26 +2729,29 @@ void SendRawCommand15693(iso15_raw_cmd_t *packet) {
     } else {
 
         // if tag answers with an error code,  it don't care about EOF packet
-        if (recvlen) {
-            recvlen = MIN(recvlen, ISO15693_MAX_RESPONSE_LENGTH);
-            reply_ng(CMD_HF_ISO15693_COMMAND, res, buf, recvlen);
-        }
-
-        // looking at the first byte of the RAW bytes to determine Subcarrier, datarate, request option
-        bool fsk = ((packet->raw[0] & ISO15_REQ_SUBCARRIER_TWO) == ISO15_REQ_SUBCARRIER_TWO);
-        bool recv_speed = ((packet->raw[0] & ISO15_REQ_DATARATE_HIGH) == ISO15_REQ_DATARATE_HIGH);
+        // normal tag answer without Option_flag also processed here
+        if (recvlen || !request_answer) {
+            if (request_answer || read_respone) {
+                recvlen = MIN(recvlen, ISO15693_MAX_RESPONSE_LENGTH);
+                reply_ng(CMD_HF_ISO15693_COMMAND, res, buf, recvlen);
+            } else {
+                reply_ng(CMD_HF_ISO15693_COMMAND, PM3_SUCCESS, NULL, 0);
+            }
+        } else {
+            // looking at the first byte of the RAW bytes to determine Subcarrier, datarate, request option
+            bool fsk = ((packet->raw[0] & ISO15_REQ_SUBCARRIER_TWO) == ISO15_REQ_SUBCARRIER_TWO);
+            bool recv_speed = ((packet->raw[0] & ISO15_REQ_DATARATE_HIGH) == ISO15_REQ_DATARATE_HIGH);
 
-        // send a single EOF to get the tag response
-        if (request_answer) {
+            // send a single EOF to get the tag response
             start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
             res = SendDataTagEOF((read_respone ? buf : NULL), sizeof(buf), start_time, ISO15693_READER_TIMEOUT, &eof_time, fsk, recv_speed, &recvlen);
-        }
 
-        if (read_respone) {
-            recvlen = MIN(recvlen, ISO15693_MAX_RESPONSE_LENGTH);
-            reply_ng(CMD_HF_ISO15693_COMMAND, res, buf, recvlen);
-        } else {
-            reply_ng(CMD_HF_ISO15693_COMMAND, PM3_SUCCESS, NULL, 0);
+            if (read_respone) {
+                recvlen = MIN(recvlen, ISO15693_MAX_RESPONSE_LENGTH);
+                reply_ng(CMD_HF_ISO15693_COMMAND, res, buf, recvlen);
+            } else {
+                reply_ng(CMD_HF_ISO15693_COMMAND, PM3_SUCCESS, NULL, 0);
+            }
         }
     }