Add non_exhaustive to all error enums

Adding an error variant to a public enum is an API breaking change, this
means making what could be small refactorings or improvements harder. If
we use `non_exhaustive` for error types then we mitigate this cost.
There is a tradeoff however, downstream users who explicitly match on
our public error types must include a wildcard pattern.

Author: tcharding

src/blockdata/block.rs

@@ -333,6 +333,7 @@ impl Block {
 
 /// An error when looking up a BIP34 block height.
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[non_exhaustive]
 pub enum Bip34Error {
     /// The block does not support BIP34 yet.
     Unsupported,

src/blockdata/script.rs

@@ -137,6 +137,7 @@ where
 /// much as it could be; patches welcome if more detailed errors
 /// would help you.
 #[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
+#[non_exhaustive]
 pub enum Error {
     /// Something did a non-minimal push; for more information see
     /// `https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#Push_operators`

src/blockdata/transaction.rs

@@ -114,6 +114,7 @@ impl fmt::Display for OutPoint {
 
 /// An error in parsing an OutPoint.
 #[derive(Clone, PartialEq, Eq, Debug)]
+#[non_exhaustive]
 pub enum ParseOutPointError {
     /// Error in TXID part.
     Txid(hashes::hex::Error),

src/consensus/encode.rs

@@ -47,6 +47,7 @@ use crate::network::{message_blockdata::Inventory, address::{Address, AddrV2Mess
 
 /// Encoding error
 #[derive(Debug)]
+#[non_exhaustive]
 pub enum Error {
     /// And I/O error
     Io(io::Error),

src/network/mod.rs

@@ -50,6 +50,7 @@ pub mod stream_reader;
 
 /// Network error
 #[derive(Debug)]
+#[non_exhaustive]
 pub enum Error {
     /// And I/O error
     Io(io::Error),

src/util/address.rs

@@ -53,6 +53,7 @@ use crate::util::schnorr::{TapTweak, UntweakedPublicKey, TweakedPublicKey};
 
 /// Address error.
 #[derive(Debug, PartialEq, Eq, Clone)]
+#[non_exhaustive]
 pub enum Error {
     /// Base58 encoding error.
     Base58(base58::Error),

src/util/amount.rs

@@ -148,6 +148,7 @@ fn denomination_from_str(mut s: &str) -> Option<Denomination> {
 
 /// An error during amount parsing.
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[non_exhaustive]
 pub enum ParseAmountError {
     /// Amount is negative.
     Negative,

src/util/base58.rs

@@ -29,6 +29,7 @@ use crate::util::{endian, key};
 
 /// An error that might occur during base58 decoding
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone)]
+#[non_exhaustive]
 pub enum Error {
     /// Invalid character encountered
     BadByte(u8),

src/util/bip32.rs

@@ -457,6 +457,7 @@ pub type KeySource = (Fingerprint, DerivationPath);
 
 /// A BIP32 error
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+#[non_exhaustive]
 pub enum Error {
     /// A pk->pk derivation was attempted on a hardened key
     CannotDeriveFromHardenedKey,

src/util/ecdsa.rs

@@ -87,6 +87,7 @@ impl FromStr for EcdsaSig {
 
 /// A key-related error.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+#[non_exhaustive]
 pub enum EcdsaSigError {
     /// Hex encoding error
     HexEncoding(hex::Error),