Merge #1171: gui: fix displayed feerate estimate

6c5f83ce15805997632cc6f698d40b4c2eb4017e gui: fix displayed feerate estimate (jp1ac4)

Pull request description:

  This is to fix #1168.

  When estimating transaction size, check if any inputs are using a relative locktime.

  I think this logic could later be moved to the `unsigned_tx_max_vbytes` method itself.

ACKs for top commit:
  edouardparis:
    ACK 6c5f83ce15805997632cc6f698d40b4c2eb4017e

Tree-SHA512: b95853b0b59729d4f8356e6e556c209025eec25e235cacf2385920f90e19f2e4a057d0d59aa28015fdfcc72f7133f122bfa3f3a9e3ced77e2f189ba43570413c

gui/src/daemon/model.rs

@@ -64,7 +64,14 @@ impl SpendTx {
         secp: &secp256k1::Secp256k1<impl secp256k1::Verification>,
         network: Network,
     ) -> Self {
-        let max_vbytes = desc.unsigned_tx_max_vbytes(&psbt.unsigned_tx, false);
+        // Use primary path if no inputs are using a relative locktime.
+        let use_primary_path = !psbt
+            .unsigned_tx
+            .input
+            .iter()
+            .map(|txin| txin.sequence)
+            .any(|seq| seq.is_relative_lock_time());
+        let max_vbytes = desc.unsigned_tx_max_vbytes(&psbt.unsigned_tx, use_primary_path);
         let change_indexes: Vec<usize> = desc
             .change_indexes(&psbt, secp)
             .into_iter()