legacy: rename TxInfo field overwintered to is_zcashlike

For v3 transaction format see:
https://zips.z.cash/zip-0202#transaction-format-version-3

legacy/firmware/signing.c

@@ -1356,8 +1356,7 @@ void signing_txack(TransactionType *tx) {
       }
       tx_init(&tp, tx->inputs_cnt, tx->outputs_cnt, tx->version, tx->lock_time,
               tx->expiry, tx->extra_data_len, coin->curve->hasher_sign,
-              coin->overwintered && tx->version >= 3, tx->version_group_id,
-              tx->timestamp);
+              coin->overwintered, tx->version_group_id, tx->timestamp);
 #if !BITCOIN_ONLY
       if (coin->decred) {
         tp.version |= (DECRED_SERIALIZE_NO_WITNESS << 16);

legacy/firmware/transaction.c

@@ -507,7 +507,7 @@ uint32_t tx_serialize_script(uint32_t size, const uint8_t *data, uint8_t *out) {
 uint32_t tx_serialize_header(TxStruct *tx, uint8_t *out) {
   int r = 4;
 #if !BITCOIN_ONLY
-  if (tx->overwintered) {
+  if (tx->is_zcashlike && tx->version >= 3) {
     uint32_t ver = tx->version | TX_OVERWINTERED;
     memcpy(out, &ver, 4);
     memcpy(out + 4, &(tx->version_group_id), 4);
@@ -533,7 +533,7 @@ uint32_t tx_serialize_header(TxStruct *tx, uint8_t *out) {
 uint32_t tx_serialize_header_hash(TxStruct *tx) {
   int r = 4;
 #if !BITCOIN_ONLY
-  if (tx->overwintered) {
+  if (tx->is_zcashlike && tx->version >= 3) {
     uint32_t ver = tx->version | TX_OVERWINTERED;
     hasher_Update(&(tx->hasher), (const uint8_t *)&ver, 4);
     hasher_Update(&(tx->hasher), (const uint8_t *)&(tx->version_group_id), 4);
@@ -684,7 +684,7 @@ uint32_t tx_serialize_middle_hash(TxStruct *tx) {
 uint32_t tx_serialize_footer(TxStruct *tx, uint8_t *out) {
   memcpy(out, &(tx->lock_time), 4);
 #if !BITCOIN_ONLY
-  if (tx->overwintered && tx->version == 4) {
+  if (tx->is_zcashlike && tx->version == 4) {
     memcpy(out + 4, &(tx->expiry), 4);
     memzero(out + 8, 8);  // valueBalance
     out[16] = 0x00;       // nShieldedSpend
@@ -703,7 +703,7 @@ uint32_t tx_serialize_footer(TxStruct *tx, uint8_t *out) {
 uint32_t tx_serialize_footer_hash(TxStruct *tx) {
   hasher_Update(&(tx->hasher), (const uint8_t *)&(tx->lock_time), 4);
 #if !BITCOIN_ONLY
-  if (tx->overwintered) {
+  if (tx->is_zcashlike && tx->version >= 3) {
     hasher_Update(&(tx->hasher), (const uint8_t *)&(tx->expiry), 4);
     return 8;
   }
@@ -794,7 +794,7 @@ uint32_t tx_serialize_extra_data_hash(TxStruct *tx, const uint8_t *data,
 
 void tx_init(TxStruct *tx, uint32_t inputs_len, uint32_t outputs_len,
              uint32_t version, uint32_t lock_time, uint32_t expiry,
-             uint32_t extra_data_len, HasherType hasher_sign, bool overwintered,
+             uint32_t extra_data_len, HasherType hasher_sign, bool is_zcashlike,
              uint32_t version_group_id, uint32_t timestamp) {
   tx->inputs_len = inputs_len;
   tx->outputs_len = outputs_len;
@@ -808,7 +808,7 @@ void tx_init(TxStruct *tx, uint32_t inputs_len, uint32_t outputs_len,
   tx->size = 0;
   tx->is_segwit = false;
   tx->is_decred = false;
-  tx->overwintered = overwintered;
+  tx->is_zcashlike = is_zcashlike;
   tx->version_group_id = version_group_id;
   tx->timestamp = timestamp;
   hasher_Init(&(tx->hasher), hasher_sign);

legacy/firmware/transaction.h

@@ -41,11 +41,11 @@ typedef struct {
   uint32_t expiry;
   bool is_segwit;
   bool is_decred;
+  bool is_zcashlike;
 
   uint32_t have_inputs;
   uint32_t have_outputs;
 
-  bool overwintered;
   uint32_t extra_data_len;
   uint32_t extra_data_received;
 
@@ -92,7 +92,7 @@ uint32_t tx_serialize_decred_witness(TxStruct *tx, const TxInputType *input,
 
 void tx_init(TxStruct *tx, uint32_t inputs_len, uint32_t outputs_len,
              uint32_t version, uint32_t lock_time, uint32_t expiry,
-             uint32_t extra_data_len, HasherType hasher_sign, bool overwintered,
+             uint32_t extra_data_len, HasherType hasher_sign, bool is_zcashlike,
              uint32_t version_group_id, uint32_t timestamp);
 uint32_t tx_serialize_header_hash(TxStruct *tx);
 uint32_t tx_serialize_input_hash(TxStruct *tx, const TxInputType *input);