core/sign_tx: In write_tx_header() rename has_segwit parameter to witness_marker and clarify usage.

core/src/apps/wallet/sign_tx/bitcoin.py

@@ -291,7 +291,7 @@ class Bitcoin:
         # should come out the same as h_confirmed, checked before signing the digest
         h_check = self.create_hash_writer()
 
-        self.write_tx_header(h_sign, self.tx, has_segwit=False)
+        self.write_tx_header(h_sign, self.tx, witness_marker=False)
         writers.write_varint(h_sign, self.tx.inputs_count)
 
         for i in range(self.tx.inputs_count):
@@ -374,8 +374,8 @@ class Bitcoin:
 
         txh = self.create_hash_writer()
 
-        # TODO set has_segwit correctly
-        self.write_tx_header(txh, tx, has_segwit=False)
+        # witnesses are not included in txid hash
+        self.write_tx_header(txh, tx, witness_marker=False)
         writers.write_varint(txh, tx.inputs_cnt)
 
         for i in range(tx.inputs_cnt):
@@ -431,10 +431,13 @@ class Bitcoin:
         writers.write_tx_output(w, txo, script_pubkey)
 
     def write_tx_header(
-        self, w: writers.Writer, tx: Union[SignTx, TransactionType], has_segwit: bool
+        self,
+        w: writers.Writer,
+        tx: Union[SignTx, TransactionType],
+        witness_marker: bool,
     ) -> None:
         writers.write_uint32(w, tx.version)  # nVersion
-        if has_segwit:
+        if witness_marker:
             writers.write_varint(w, 0x00)  # segwit witness marker
             writers.write_varint(w, 0x01)  # segwit witness flag
 

core/src/apps/wallet/sign_tx/bitcoinlike.py

@@ -65,12 +65,15 @@ class Bitcoinlike(Bitcoin):
         return hashtype
 
     def write_tx_header(
-        self, w: writers.Writer, tx: Union[SignTx, TransactionType], has_segwit: bool
+        self,
+        w: writers.Writer,
+        tx: Union[SignTx, TransactionType],
+        witness_marker: bool,
     ) -> None:
         writers.write_uint32(w, tx.version)  # nVersion
         if self.coin.timestamp:
             writers.write_uint32(w, tx.timestamp)
-        if has_segwit:
+        if witness_marker:
             writers.write_varint(w, 0x00)  # segwit witness marker
             writers.write_varint(w, 0x01)  # segwit witness flag
 

core/src/apps/wallet/sign_tx/decred.py

@@ -32,7 +32,7 @@ class Decred(Bitcoin):
         ensure(coin.decred)
         super().__init__(tx, keychain, coin)
 
-        self.write_tx_header(self.serialized_tx, self.tx, has_segwit=False)
+        self.write_tx_header(self.serialized_tx, self.tx, witness_marker=True)
         writers.write_varint(self.serialized_tx, self.tx.inputs_count)
 
     def init_hash143(self) -> None:
@@ -163,12 +163,17 @@ class Decred(Bitcoin):
         writers.write_tx_output_decred(w, txo, script_pubkey)
 
     def write_tx_header(
-        self, w: writers.Writer, tx: Union[SignTx, TransactionType], has_segwit: bool
+        self,
+        w: writers.Writer,
+        tx: Union[SignTx, TransactionType],
+        witness_marker: bool,
     ) -> None:
-        if isinstance(tx, TransactionType):
-            version = tx.version | DECRED_SERIALIZE_NO_WITNESS
-        else:
+        # The upper 16 bits of the transaction version specify the serialization
+        # format and the lower 16 bits specify the version number.
+        if witness_marker:
             version = tx.version | DECRED_SERIALIZE_FULL
+        else:
+            version = tx.version | DECRED_SERIALIZE_NO_WITNESS
 
         writers.write_uint32(w, version)
 

core/src/apps/wallet/sign_tx/zcash.py

@@ -77,7 +77,7 @@ class Overwintered(Bitcoinlike):
         await self.sign_nonsegwit_bip143_input(i_sign)
 
     def write_tx_header(
-        self, w: Writer, tx: Union[SignTx, TransactionType], has_segwit: bool
+        self, w: Writer, tx: Union[SignTx, TransactionType], witness_marker: bool
     ) -> None:
         # nVersion | fOverwintered
         write_uint32(w, tx.version | OVERWINTERED)