From 9a7b1c232b494dccdce091a46d916cc411a612a1 Mon Sep 17 00:00:00 2001
From: "Tobin C. Harding" <me@tobin.cc>
Date: Sun, 27 Oct 2024 08:29:22 +1100
Subject: [PATCH] Wrap the bech32 decoding error

We do not want `bech32` to appear in the public API of the `address`
module in case `bech32` does not stabalize before the soon-to-be-created
`address` crates does.

We already had a go at removing it but forgot one error variant - wrap
the variant in a new type with a private inner bech32 error field.
---
 bitcoin/src/address/error.rs | 24 +++++++++++++++++++-----
 bitcoin/src/address/mod.rs   |  5 +++--
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/bitcoin/src/address/error.rs b/bitcoin/src/address/error.rs
index 58d0cd1e5..b972f7b12 100644
--- a/bitcoin/src/address/error.rs
+++ b/bitcoin/src/address/error.rs
@@ -166,7 +166,7 @@ impl std::error::Error for NetworkValidationError {}
 #[non_exhaustive]
 pub enum Bech32Error {
     /// Parse segwit Bech32 error.
-    ParseBech32(bech32::segwit::DecodeError),
+    ParseBech32(ParseBech32Error),
     /// A witness version conversion/parsing error.
     WitnessVersion(witness_version::TryFromError),
     /// A witness program error.
@@ -204,10 +204,6 @@ impl std::error::Error for Bech32Error {
     }
 }
 
-impl From<bech32::segwit::DecodeError> for Bech32Error {
-    fn from(e: bech32::segwit::DecodeError) -> Self { Self::ParseBech32(e) }
-}
-
 impl From<witness_version::TryFromError> for Bech32Error {
     fn from(e: witness_version::TryFromError) -> Self { Self::WitnessVersion(e) }
 }
@@ -220,6 +216,24 @@ impl From<UnknownHrpError> for Bech32Error {
     fn from(e: UnknownHrpError) -> Self { Self::UnknownHrp(e) }
 }
 
+/// Bech32 parsing related error.
+// This wrapper exists because we do not want to expose the `bech32` crate in our public API.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ParseBech32Error(pub(crate) bech32::segwit::DecodeError);
+
+internals::impl_from_infallible!(ParseBech32Error);
+
+impl fmt::Display for ParseBech32Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write_err!(f, "bech32 parsing error"; self.0)
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for ParseBech32Error {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { Some(&self.0) }
+}
+
 /// Base58 related error.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[non_exhaustive]
diff --git a/bitcoin/src/address/mod.rs b/bitcoin/src/address/mod.rs
index 87744113b..9eac89094 100644
--- a/bitcoin/src/address/mod.rs
+++ b/bitcoin/src/address/mod.rs
@@ -61,7 +61,7 @@ use crate::taproot::TapNodeHash;
 pub use self::error::{
         Base58Error, Bech32Error, FromScriptError, InvalidBase58PayloadLengthError,
         InvalidLegacyPrefixError, LegacyAddressTooLongError, NetworkValidationError,
-        ParseError, UnknownAddressTypeError, UnknownHrpError
+        ParseError, UnknownAddressTypeError, UnknownHrpError, ParseBech32Error,
 };
 
 /// The different types of addresses.
@@ -803,7 +803,8 @@ impl Address<NetworkUnchecked> {
 
     /// Parse a bech32 Address string
     pub fn from_bech32_str(s: &str) -> Result<Address<NetworkUnchecked>, Bech32Error> {
-        let (hrp, witness_version, data) = bech32::segwit::decode(s)?;
+        let (hrp, witness_version, data) = bech32::segwit::decode(s)
+            .map_err(|e| Bech32Error::ParseBech32(ParseBech32Error(e)))?;
         let version = WitnessVersion::try_from(witness_version.to_u8())?;
         let program = WitnessProgram::new(version, &data)
             .expect("bech32 guarantees valid program length for witness");