test: Avoid CScript() as default function argument

This does not cause any issues, because CScript in the tests are const.
However, this change allows to enable the
"function-call-in-default-argument (B008)" lint rule.

test/functional/data/invalid_txs.py

@@ -192,7 +192,7 @@ class SpendTooMuch(BadTxTemplate):
 
     def get_tx(self):
         return create_tx_with_script(
-            self.spend_tx, 0, script_pub_key=basic_p2sh, amount=(self.spend_avail + 1))
+            self.spend_tx, 0, output_script=basic_p2sh, amount=(self.spend_avail + 1))
 
 
 class CreateNegative(BadTxTemplate):
@@ -242,7 +242,7 @@ class TooManySigops(BadTxTemplate):
         lotsa_checksigs = CScript([OP_CHECKSIG] * (MAX_BLOCK_SIGOPS))
         return create_tx_with_script(
             self.spend_tx, 0,
-            script_pub_key=lotsa_checksigs,
+            output_script=lotsa_checksigs,
             amount=1)
 
 def getDisabledOpcodeTemplate(opcode):

test/functional/feature_block.py

@@ -1326,8 +1326,10 @@ class FullBlockTest(BitcoinTestFramework):
         block.vtx.extend(tx_list)
 
     # this is a little handier to use than the version in blocktools.py
-    def create_tx(self, spend_tx, n, value, script=CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE])):
+    def create_tx(self, spend_tx, n, value, output_script=None):
-        return create_tx_with_script(spend_tx, n, amount=value, script_pub_key=script)
+        if output_script is None:
+            output_script = CScript([OP_TRUE, OP_DROP] * 15 + [OP_TRUE])
+        return create_tx_with_script(spend_tx, n, amount=value, output_script=output_script)
 
     # sign a transaction, using the key we know about
     # this signs input 0 in tx, which is assumed to be spending output 0 in spend_tx
@@ -1338,13 +1340,17 @@ class FullBlockTest(BitcoinTestFramework):
             return
         sign_input_legacy(tx, 0, spend_tx.vout[0].scriptPubKey, self.coinbase_key)
 
-    def create_and_sign_transaction(self, spend_tx, value, script=CScript([OP_TRUE])):
+    def create_and_sign_transaction(self, spend_tx, value, output_script=None):
-        tx = self.create_tx(spend_tx, 0, value, script)
+        if output_script is None:
+            output_script = CScript([OP_TRUE])
+        tx = self.create_tx(spend_tx, 0, value, output_script=output_script)
         self.sign_tx(tx, spend_tx)
         tx.rehash()
         return tx
 
-    def next_block(self, number, spend=None, additional_coinbase_value=0, script=CScript([OP_TRUE]), *, version=4):
+    def next_block(self, number, spend=None, additional_coinbase_value=0, *, script=None, version=4):
+        if script is None:
+            script = CScript([OP_TRUE])
         if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
@@ -1361,7 +1367,7 @@ class FullBlockTest(BitcoinTestFramework):
         else:
             coinbase.vout[0].nValue += spend.vout[0].nValue - 1  # all but one satoshi to fees
             coinbase.rehash()
-            tx = self.create_tx(spend, 0, 1, script)  # spend 1 satoshi
+            tx = self.create_tx(spend, 0, 1, output_script=script)  # spend 1 satoshi
             self.sign_tx(tx, spend)
             tx.rehash()
             block = create_block(base_block_hash, coinbase, block_time, version=version, txlist=[tx])

test/functional/test_framework/blocktools.py

@@ -154,16 +154,18 @@ def create_coinbase(height, pubkey=None, *, script_pubkey=None, extra_output_scr
     coinbase.calc_sha256()
     return coinbase
 
-def create_tx_with_script(prevtx, n, script_sig=b"", *, amount, script_pub_key=CScript()):
+def create_tx_with_script(prevtx, n, script_sig=b"", *, amount, output_script=None):
     """Return one-input, one-output transaction object
        spending the prevtx's n-th output with the given amount.
 
        Can optionally pass scriptPubKey and scriptSig, default is anyone-can-spend output.
     """
+    if output_script is None:
+        output_script = CScript()
     tx = CTransaction()
     assert n < len(prevtx.vout)
     tx.vin.append(CTxIn(COutPoint(prevtx.sha256, n), script_sig, SEQUENCE_FINAL))
-    tx.vout.append(CTxOut(amount, script_pub_key))
+    tx.vout.append(CTxOut(amount, output_script))
     tx.calc_sha256()
     return tx