From c6cd47a5dd27e972df5901cb8bdc8793f4832597 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@electriccoin.co>
Date: Thu, 29 Apr 2021 12:57:40 +1200
Subject: [PATCH] Fix Rand.u8() to return unsigned integers

Existing test vector generators are adjusted to use Rand.i8() so they
generate the same test vectors. We should evaluate these later to
determine whether they should actually use Rand.u8() (and update the
test vectors across the ecosystem).
---
 transaction.py | 12 ++++++------
 tv_rand.py     |  5 ++++-
 zip_0143.py    |  2 +-
 zip_0243.py    |  2 +-
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/transaction.py b/transaction.py
index 7a2582b..aa3ca64 100644
--- a/transaction.py
+++ b/transaction.py
@@ -155,7 +155,7 @@ RAND_OPCODES = [
 class Script(object):
     def __init__(self, rand):
         self._script = bytes([
-            rand.a(RAND_OPCODES) for i in range(rand.u8() % 10)
+            rand.a(RAND_OPCODES) for i in range(rand.i8() % 10)
         ])
 
     def raw(self):
@@ -212,11 +212,11 @@ class Transaction(object):
             self.nVersion = rand.u32() & ((1 << 31) - 1)
 
         self.vin = []
-        for i in range(rand.u8() % 3):
+        for i in range(rand.i8() % 3):
             self.vin.append(TxIn(rand))
 
         self.vout = []
-        for i in range(rand.u8() % 3):
+        for i in range(rand.i8() % 3):
             self.vout.append(TxOut(rand))
 
         self.nLockTime = rand.u32()
@@ -227,14 +227,14 @@ class Transaction(object):
         self.vShieldedSpends = []
         self.vShieldedOutputs = []
         if self.nVersion >= SAPLING_TX_VERSION:
-            for _ in range(rand.u8() % 5):
+            for _ in range(rand.i8() % 5):
                 self.vShieldedSpends.append(SpendDescription(rand))
-            for _ in range(rand.u8() % 5):
+            for _ in range(rand.i8() % 5):
                 self.vShieldedOutputs.append(OutputDescription(rand))
 
         self.vJoinSplit = []
         if self.nVersion >= 2:
-            for i in range(rand.u8() % 3):
+            for i in range(rand.i8() % 3):
                 self.vJoinSplit.append(JoinSplit(rand, self.fOverwintered and self.nVersion >= SAPLING_TX_VERSION))
             if len(self.vJoinSplit) > 0:
                 self.joinSplitPubKey = rand.b(32) # Potentially invalid
diff --git a/tv_rand.py b/tv_rand.py
index 3035286..e064332 100644
--- a/tv_rand.py
+++ b/tv_rand.py
@@ -12,9 +12,12 @@ class Rand(object):
     def v(self, l, f):
         return struct.unpack(f, self.b(l))[0]
 
-    def u8(self):
+    def i8(self):
         return self.v(1, 'b')
 
+    def u8(self):
+        return self.v(1, 'B')
+
     def u32(self):
         return self.v(4, '<I')
 
diff --git a/zip_0143.py b/zip_0143.py
index 273059e..0403d84 100644
--- a/zip_0143.py
+++ b/zip_0143.py
@@ -113,7 +113,7 @@ def main():
     for i in range(10):
         tx = Transaction(rand, OVERWINTER_TX_VERSION)
         scriptCode = Script(rand)
-        nIn = rand.u8() % (len(tx.vin) + 1)
+        nIn = rand.i8() % (len(tx.vin) + 1)
         if nIn == len(tx.vin):
             nIn = NOT_AN_INPUT
         nHashType = SIGHASH_ALL if nIn == NOT_AN_INPUT else rand.a([
diff --git a/zip_0243.py b/zip_0243.py
index d54421a..3edef09 100644
--- a/zip_0243.py
+++ b/zip_0243.py
@@ -120,7 +120,7 @@ def main():
     for _ in range(10):
         tx = Transaction(rand, SAPLING_TX_VERSION)
         scriptCode = Script(rand)
-        nIn = rand.u8() % (len(tx.vin) + 1)
+        nIn = rand.i8() % (len(tx.vin) + 1)
         if nIn == len(tx.vin):
             nIn = NOT_AN_INPUT
         nHashType = SIGHASH_ALL if nIn == NOT_AN_INPUT else rand.a([