slight rework

shared/psbt.py

@@ -5,7 +5,6 @@
 import stash, gc, history, sys, ngu, ckcc, chains
 from ustruct import unpack_from, unpack, pack
 from ubinascii import hexlify as b2a_hex
-from ucollections import OrderedDict
 from utils import xfp2str, B2A, keypath_to_str
 from utils import seconds2human_readable, datetime_from_timestamp, datetime_to_str
 from chains import NLOCK_IS_TIME
@@ -1762,20 +1761,16 @@ class psbtObject(psbtProxy):
         foreign = []
         total_in = 0
 
-        prevouts_max_len = 50
-        prevouts = OrderedDict()
+        prevouts = set()
 
         for i, txi in self.input_iter():
             # check for duplicate inputs
-            if len(prevouts) >= prevouts_max_len:
-                first = next(iter(prevouts))  # O(1) in mpy
-                del prevouts[first]
+            k = (txi.prevout.hash, txi.prevout.n)
+            if k in prevouts: 
+                raise FatalPSBTIssue("Duplicate inputs")
 
-            k = txi.prevout.n, txi.prevout.hash
-            if k in prevouts:  # O(1)
-                raise FatalPSBTIssue("Duplicate inputs!")
-
-            prevouts[k] = True
+            if len(prevouts) < 100:
+                prevouts.add(k)
 
             inp = self.inputs[i]
             if inp.fully_signed:

testing/test_sign.py

@@ -3647,16 +3647,14 @@ def test_txn_nVersion_zero(segwit, fake_txn, start_sign, cap_story, goto_home):
     assert "txn version" in story
 
 @pytest.mark.parametrize("segwit_in", [True, False])
-@pytest.mark.parametrize("num_ins", [2, 50, 51])
+@pytest.mark.parametrize("num_ins", [2, 110])
 def test_duplicate_inputs(segwit_in, num_ins, fake_txn, start_sign, end_sign, cap_story):
     psbt = fake_txn(num_ins, 2, segwit_in=segwit_in, dupe_ins=[num_ins-1])
     start_sign(psbt)
     title, story = cap_story()
-    if num_ins <= 50:
-        # only works if duplicate is no longer than 50 inputs from original
-        assert "Duplicate inputs!" in story
+    if num_ins <= 100:
+        assert "Duplicate input" in story
     else:
-        # does not work
         assert title == "OK TO SEND?"
 
 # EOF

testing/txn.py

@@ -27,10 +27,6 @@ def fake_txn(dev, pytestconfig):
              psbt_v2=None, input_amount=1E8, unknown_out_script=None, lock_time=0,
              sequences=None, sighashes=None, dupe_ins=[]):
 
-        # dupe_ins cannot contain zero, as that will be the duplicated input
-        if dupe_ins:
-            assert 0 not in dupe_ins
-
         psbt = BasicPSBT()
 
         if psbt_v2 is None:
@@ -62,17 +58,12 @@ def fake_txn(dev, pytestconfig):
             # - each input is 1BTC
 
             # addr where the fake money will be stored.
-            if i in dupe_ins:
-                # always duplicate zeroth input
-                subkey = mk.subkey_for_path(subpath % 0)
-            else:
-                subkey = mk.subkey_for_path(subpath % i)
+            subkey = mk.subkey_for_path(subpath % i)
             sec = subkey.sec()
             assert len(sec) == 33, "expect compressed"
             assert subpath[0:2] == '0/'
 
-            idx = 0 if i in dupe_ins else i
-            psbt.inputs[i].bip32_paths[sec] = xfp + struct.pack('<II', 0, idx)
+            psbt.inputs[i].bip32_paths[sec] = xfp + struct.pack('<II', 0, i)
 
             # UTXO that provides the funding for to-be-signed txn
             supply = CTransaction()
@@ -102,7 +93,7 @@ def fake_txn(dev, pytestconfig):
 
             if segwit_in:
                 # just utxo for segwit
-                psbt.inputs[i].witness_utxo = supply.vout[0 if i in dupe_ins else -1].serialize()
+                psbt.inputs[i].witness_utxo = supply.vout[-1].serialize()
             else:
                 # whole tx for pre-segwit
                 psbt.inputs[i].utxo = supply.serialize_with_witness()
@@ -131,14 +122,20 @@ def fake_txn(dev, pytestconfig):
                     seq = sequences[0]
 
             spendable = CTxIn(COutPoint(supply.sha256, 0), nSequence=seq)
-            txn.vin.append(spendable)
+            if i not in dupe_ins:
+                txn.vin.append(spendable)
 
-            if psbt_v2:
-                psbt.inputs[i].previous_txid = supply.hash
-                psbt.inputs[i].prevout_idx = 0
-                psbt.inputs[i].sequence = seq
-                # psbt.inputs[i].req_time_locktime = None
-                # psbt.inputs[i].req_height_locktime = None
+                if psbt_v2:
+                    psbt.inputs[i].previous_txid = supply.hash
+                    psbt.inputs[i].prevout_idx = 0
+                    psbt.inputs[i].sequence = seq
+                    # psbt.inputs[i].req_time_locktime = None
+                    # psbt.inputs[i].req_height_locktime = None
+            else:
+                assert i != 0, 'cant dup first input'           
+                txn.vin.append(txn.vin[-1])
+                from copy import deepcopy
+                psbt.inputs[i] = deepcopy(psbt.inputs[i-1])
 
         for i in range(num_outs):
             # random P2PKH