From 9768e4af78ee12cef1e0e52f0fbc502a50251ced Mon Sep 17 00:00:00 2001
From: CalDescent <>
Date: Wed, 18 May 2022 19:14:01 +0100
Subject: [PATCH] Allow lock time to be optionally set when adding a
 transparent input.

---
 zcash_primitives/src/transaction/builder.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/zcash_primitives/src/transaction/builder.rs b/zcash_primitives/src/transaction/builder.rs
index 55fef60..8e73839 100644
--- a/zcash_primitives/src/transaction/builder.rs
+++ b/zcash_primitives/src/transaction/builder.rs
@@ -175,6 +175,7 @@ impl TransparentInputs {
         coin: TxOut,
         secret: Vec<u8>,
         redeem_script: Vec<u8>,
+        lock_time: u32,
     ) -> Result<(), Error> {
         if coin.value.is_negative() {
             return Err(Error::InvalidAmount);
@@ -197,6 +198,12 @@ impl TransparentInputs {
         mtx.vin.push(TxIn::new(utxo));
         self.inputs.push(TransparentInputInfo { sk, pubkey, coin, secret, redeem_script });
 
+        // Set lock time if present
+        if (lock_time > 0) {
+            mtx.sequence = 4294967294; // max value (0xFFFFFFFF - 1), so lockTime can be used but not RBF
+            mtx.lock_time = lock_time;
+        }
+
         Ok(())
     }
 
@@ -409,7 +416,8 @@ impl<R: RngCore + CryptoRng> Builder<R> {
         utxo: OutPoint,
         coin: TxOut,
     ) -> Result<(), Error> {
-        self.transparent_inputs.push(&mut self.mtx, sk, utxo, coin, Vec::new(), Vec::new())
+        let lock_time: u32 = 0;
+        self.transparent_inputs.push(&mut self.mtx, sk, utxo, coin, Vec::new(), Vec::new(), lock_time)
     }
 
     /// Adds a transparent coin to be spent in this transaction, with HTLC secret.
@@ -421,8 +429,9 @@ impl<R: RngCore + CryptoRng> Builder<R> {
         coin: TxOut,
         secret: Vec<u8>,
         redeem_script: Vec<u8>,
+        lock_time: u32,
     ) -> Result<(), Error> {
-        self.transparent_inputs.push(&mut self.mtx, sk, utxo, coin, secret, redeem_script)
+        self.transparent_inputs.push(&mut self.mtx, sk, utxo, coin, secret, redeem_script, lock_time)
     }
 
     /// Adds a transparent address to send funds to.