From cf800a1b07133e159f1a65bfbeb50ebaf68cb06d Mon Sep 17 00:00:00 2001
From: "Tobin C. Harding" <me@tobin.cc>
Date: Thu, 27 Jun 2024 15:37:27 +1000
Subject: [PATCH] Remove bech32 dependency from blockdata

We have a single usage of the `bech32` crate inside the `blockdata`
module, to convert a `WitnessVersion` to a `Fe32`. We then have a single
call site where we use the conversion in the `address` module.

This code was written without thinking to hard about the introduced
dependency on `bech32`, in hindsite it shouldn't have been added.

In preparation for splitting a bunch of code in `blockdata` out into the
`primitives` crate remove the `bech32` stuff from the `witness_version`
module.
---
 bitcoin/src/address/mod.rs                      |  6 ++++--
 bitcoin/src/blockdata/script/witness_version.rs | 16 ----------------
 2 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/bitcoin/src/address/mod.rs b/bitcoin/src/address/mod.rs
index 1bb77e1ab..99d539e80 100644
--- a/bitcoin/src/address/mod.rs
+++ b/bitcoin/src/address/mod.rs
@@ -33,6 +33,7 @@ use core::marker::PhantomData;
 use core::str::FromStr;
 
 use bech32::primitives::hrp::Hrp;
+use bech32::primitives::gf32::Fe32;
 use hashes::{sha256, HashEngine};
 use secp256k1::{Secp256k1, Verification, XOnlyPublicKey};
 
@@ -168,7 +169,8 @@ impl fmt::Display for AddressInner {
             }
             Segwit { program, hrp } => {
                 let hrp = hrp.to_hrp();
-                let version = program.version().to_fe();
+                let version = Fe32::try_from(program.version().to_num())
+                    .expect("version nums 0-16 are valid fe32 values");
                 let program = program.program().as_ref();
 
                 if fmt.alternate() {
@@ -829,7 +831,7 @@ impl FromStr for Address<NetworkUnchecked> {
 
     fn from_str(s: &str) -> Result<Address<NetworkUnchecked>, ParseError> {
         if let Ok((hrp, witness_version, data)) = bech32::segwit::decode(s) {
-            let version = WitnessVersion::try_from(witness_version)?;
+            let version = WitnessVersion::try_from(witness_version.to_u8())?;
             let program = WitnessProgram::new(version, &data)
                 .expect("bech32 guarantees valid program length for witness");
 
diff --git a/bitcoin/src/blockdata/script/witness_version.rs b/bitcoin/src/blockdata/script/witness_version.rs
index 0974da625..826286929 100644
--- a/bitcoin/src/blockdata/script/witness_version.rs
+++ b/bitcoin/src/blockdata/script/witness_version.rs
@@ -10,7 +10,6 @@
 use core::fmt;
 use core::str::FromStr;
 
-use bech32::Fe32;
 use internals::write_err;
 use units::{parse, ParseIntError};
 
@@ -71,11 +70,6 @@ impl WitnessVersion {
     /// version in bitcoin script. Thus, there is no function to directly convert witness version
     /// into a byte since the conversion requires context (bitcoin script or just a version number).
     pub fn to_num(self) -> u8 { self as u8 }
-
-    /// Converts this witness version to a GF32 field element.
-    pub fn to_fe(self) -> Fe32 {
-        Fe32::try_from(self.to_num()).expect("0-16 are valid fe32 values")
-    }
 }
 
 /// Prints [`WitnessVersion`] number (from 0 to 16) as integer, without any prefix or suffix.
@@ -92,12 +86,6 @@ impl FromStr for WitnessVersion {
     }
 }
 
-impl TryFrom<bech32::Fe32> for WitnessVersion {
-    type Error = TryFromError;
-
-    fn try_from(value: Fe32) -> Result<Self, Self::Error> { Self::try_from(value.to_u8()) }
-}
-
 impl TryFrom<u8> for WitnessVersion {
     type Error = TryFromError;
 
@@ -152,10 +140,6 @@ impl<'a> TryFrom<Instruction<'a>> for WitnessVersion {
     }
 }
 
-impl From<WitnessVersion> for Fe32 {
-    fn from(version: WitnessVersion) -> Self { version.to_fe() }
-}
-
 impl From<WitnessVersion> for Opcode {
     fn from(version: WitnessVersion) -> Opcode {
         match version {