Merge rust-bitcoin/rust-bitcoin#6667: Make the `WitnessesEncoder` private

### bitcoin/src/blockdata/transaction.rs
@@ -36,7 +36,7 @@ pub use primitives::transaction::BlockHashDecoderError;
 pub use primitives::transaction::{
     BlockHashDecoder, Ntxid, OutPoint, OutPointDecoder, OutPointEncoder, Transaction,
     TransactionDecoder, TransactionEncoder, TxIn, TxInDecoder, TxInEncoder, TxOut, TxOutDecoder,
-    TxOutEncoder, Txid, Version, VersionDecoder, VersionEncoder, WitnessesEncoder, Wtxid,
+    TxOutEncoder, Txid, Version, VersionDecoder, VersionEncoder, Wtxid,
 };
 
 #[doc(no_inline)]

### primitives/api/all-features.txt
@@ -5804,45 +5804,6 @@ impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::VersionE
   pub unsafe fn bitcoin_primitives::transaction::VersionEncoder<'e>::clone_to_uninit(&self, dest: *mut u8) [impl: impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::VersionEncoder<'e> where T: core::clone::Clone]
 impl<T> core::convert::From<T> for bitcoin_primitives::transaction::VersionEncoder<'e>
   pub fn bitcoin_primitives::transaction::VersionEncoder<'e>::from(t: T) -> T [impl: impl<T> core::convert::From<T> for bitcoin_primitives::transaction::VersionEncoder<'e>]
-pub struct bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> bitcoin_primitives::transaction::WitnessesEncoder<'e>
-pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::new(inputs: &'e [bitcoin_primitives::transaction::TxIn]) -> Self
-impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'_>::advance(&mut self) -> bitcoin_consensus_encoding::encode::EncoderStatus [impl: impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'_>::current_chunk(&self) -> &[u8] [impl: impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>]
-impl<'e> core::clone::Clone for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone(&self) -> bitcoin_primitives::transaction::WitnessesEncoder<'e> [impl: impl<'e> core::clone::Clone for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
-impl<'e> core::fmt::Debug for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result [impl: impl<'e> core::fmt::Debug for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
-impl<'e> core::marker::Freeze for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Send for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Sync for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Unpin for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::UnsafeUnpin for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::panic::unwind_safe::RefUnwindSafe for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::panic::unwind_safe::UnwindSafe for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<T, U> core::convert::Into<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::From<T>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::into(self) -> U [impl: impl<T, U> core::convert::Into<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::From<T>]
-impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Error = core::convert::Infallible [impl: impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::try_from(value: U) -> core::result::Result<T, <T as core::convert::TryFrom<U>>::Error> [impl: impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>]
-impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Error = <U as core::convert::TryFrom<T>>::Error [impl: impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::try_into(self) -> core::result::Result<U, <U as core::convert::TryFrom<T>>::Error> [impl: impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>]
-impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Owned = T [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone_into(&self, target: &mut T) [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::to_owned(&self) -> T [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-impl<T> core::any::Any for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: 'static + ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::type_id(&self) -> core::any::TypeId [impl: impl<T> core::any::Any for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: 'static + ?core::marker::Sized]
-impl<T> core::borrow::Borrow<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::borrow(&self) -> &T [impl: impl<T> core::borrow::Borrow<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized]
-impl<T> core::borrow::BorrowMut<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::borrow_mut(&mut self) -> &mut T [impl: impl<T> core::borrow::BorrowMut<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized]
-impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone
-  pub unsafe fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone_to_uninit(&self, dest: *mut u8) [impl: impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-impl<T> core::convert::From<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::from(t: T) -> T [impl: impl<T> core::convert::From<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
 pub struct bitcoin_primitives::transaction::Wtxid(_)
 impl bitcoin_primitives::Wtxid
 pub const bitcoin_primitives::Wtxid::COINBASE: Self

### primitives/api/alloc-only.txt
@@ -5395,45 +5395,6 @@ impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::VersionE
   pub unsafe fn bitcoin_primitives::transaction::VersionEncoder<'e>::clone_to_uninit(&self, dest: *mut u8) [impl: impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::VersionEncoder<'e> where T: core::clone::Clone]
 impl<T> core::convert::From<T> for bitcoin_primitives::transaction::VersionEncoder<'e>
   pub fn bitcoin_primitives::transaction::VersionEncoder<'e>::from(t: T) -> T [impl: impl<T> core::convert::From<T> for bitcoin_primitives::transaction::VersionEncoder<'e>]
-pub struct bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> bitcoin_primitives::transaction::WitnessesEncoder<'e>
-pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::new(inputs: &'e [bitcoin_primitives::transaction::TxIn]) -> Self
-impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'_>::advance(&mut self) -> bitcoin_consensus_encoding::encode::EncoderStatus [impl: impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'_>::current_chunk(&self) -> &[u8] [impl: impl bitcoin_consensus_encoding::encode::Encoder for bitcoin_primitives::transaction::WitnessesEncoder<'_>]
-impl<'e> core::clone::Clone for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone(&self) -> bitcoin_primitives::transaction::WitnessesEncoder<'e> [impl: impl<'e> core::clone::Clone for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
-impl<'e> core::fmt::Debug for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result [impl: impl<'e> core::fmt::Debug for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
-impl<'e> core::marker::Freeze for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Send for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Sync for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::Unpin for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::marker::UnsafeUnpin for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::panic::unwind_safe::RefUnwindSafe for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<'e> core::panic::unwind_safe::UnwindSafe for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-impl<T, U> core::convert::Into<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::From<T>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::into(self) -> U [impl: impl<T, U> core::convert::Into<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::From<T>]
-impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Error = core::convert::Infallible [impl: impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::try_from(value: U) -> core::result::Result<T, <T as core::convert::TryFrom<U>>::Error> [impl: impl<T, U> core::convert::TryFrom<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::Into<T>]
-impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Error = <U as core::convert::TryFrom<T>>::Error [impl: impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::try_into(self) -> core::result::Result<U, <U as core::convert::TryFrom<T>>::Error> [impl: impl<T, U> core::convert::TryInto<U> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where U: core::convert::TryFrom<T>]
-impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone
-  pub type bitcoin_primitives::transaction::WitnessesEncoder<'e>::Owned = T [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone_into(&self, target: &mut T) [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::to_owned(&self) -> T [impl: impl<T> alloc::borrow::ToOwned for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-impl<T> core::any::Any for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: 'static + ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::type_id(&self) -> core::any::TypeId [impl: impl<T> core::any::Any for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: 'static + ?core::marker::Sized]
-impl<T> core::borrow::Borrow<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::borrow(&self) -> &T [impl: impl<T> core::borrow::Borrow<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized]
-impl<T> core::borrow::BorrowMut<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::borrow_mut(&mut self) -> &mut T [impl: impl<T> core::borrow::BorrowMut<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: ?core::marker::Sized]
-impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone
-  pub unsafe fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::clone_to_uninit(&self, dest: *mut u8) [impl: impl<T> core::clone::CloneToUninit for bitcoin_primitives::transaction::WitnessesEncoder<'e> where T: core::clone::Clone]
-impl<T> core::convert::From<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e>
-  pub fn bitcoin_primitives::transaction::WitnessesEncoder<'e>::from(t: T) -> T [impl: impl<T> core::convert::From<T> for bitcoin_primitives::transaction::WitnessesEncoder<'e>]
 pub struct bitcoin_primitives::transaction::Wtxid(_)
 impl bitcoin_primitives::Wtxid
 pub const bitcoin_primitives::Wtxid::COINBASE: Self

### primitives/src/transaction.rs
@@ -695,6 +695,59 @@ enum IsSegwit {
     No,
 }
 
+/// Encodes the witnesses from a list of inputs.
+#[cfg(feature = "alloc")]
+#[derive(Debug, Clone)]
+struct WitnessesEncoder<'e> {
+    inputs: &'e [TxIn],
+    /// Encoder for the current witness being encoded.
+    cur_enc: Option<WitnessEncoder<'e>>,
+}
+
+#[cfg(feature = "alloc")]
+impl<'e> WitnessesEncoder<'e> {
+    /// Constructs a new encoder for all witnesses in a list of transaction inputs.
+    pub fn new(inputs: &'e [TxIn]) -> Self {
+        Self { inputs, cur_enc: inputs.first().map(|input| input.witness.encoder()) }
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl encoding::Encoder for WitnessesEncoder<'_> {
+    #[inline]
+    fn current_chunk(&self) -> &[u8] {
+        self.cur_enc.as_ref().map(WitnessEncoder::current_chunk).unwrap_or_default()
+    }
+
+    #[inline]
+    fn advance(&mut self) -> EncoderStatus {
+        let Some(cur) = self.cur_enc.as_mut() else {
+            return EncoderStatus::Finished;
+        };
+
+        loop {
+            // On subsequent calls, attempt to advance the current encoder and return
+            // success if this succeeds.
+            if cur.advance().has_more() {
+                return EncoderStatus::HasMore;
+            }
+            // self.inputs guaranteed to be non-empty if cur_enc is non-None.
+            self.inputs = &self.inputs[1..];
+
+            // If advancing the current encoder failed, attempt to move to the next encoder.
+            if let Some(input) = self.inputs.first() {
+                *cur = input.witness.encoder();
+                if !cur.current_chunk().is_empty() {
+                    return EncoderStatus::HasMore;
+                }
+            } else {
+                self.cur_enc = None; // shortcut the next call to advance()
+                return EncoderStatus::Finished;
+            }
+        }
+    }
+}
+
 /// How many times we have state transitioned to encoding a witness (zero-based).
 #[cfg(feature = "alloc")]
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -766,59 +819,6 @@ impl encoding::Encode for TxIn {
     }
 }
 
-/// Encodes the witnesses from a list of inputs.
-#[cfg(feature = "alloc")]
-#[derive(Debug, Clone)]
-pub struct WitnessesEncoder<'e> {
-    inputs: &'e [TxIn],
-    /// Encoder for the current witness being encoded.
-    cur_enc: Option<WitnessEncoder<'e>>,
-}
-
-#[cfg(feature = "alloc")]
-impl<'e> WitnessesEncoder<'e> {
-    /// Constructs a new encoder for all witnesses in a list of transaction inputs.
-    pub fn new(inputs: &'e [TxIn]) -> Self {
-        Self { inputs, cur_enc: inputs.first().map(|input| input.witness.encoder()) }
-    }
-}
-
-#[cfg(feature = "alloc")]
-impl encoding::Encoder for WitnessesEncoder<'_> {
-    #[inline]
-    fn current_chunk(&self) -> &[u8] {
-        self.cur_enc.as_ref().map(WitnessEncoder::current_chunk).unwrap_or_default()
-    }
-
-    #[inline]
-    fn advance(&mut self) -> EncoderStatus {
-        let Some(cur) = self.cur_enc.as_mut() else {
-            return EncoderStatus::Finished;
-        };
-
-        loop {
-            // On subsequent calls, attempt to advance the current encoder and return
-            // success if this succeeds.
-            if cur.advance().has_more() {
-                return EncoderStatus::HasMore;
-            }
-            // self.inputs guaranteed to be non-empty if cur_enc is non-None.
-            self.inputs = &self.inputs[1..];
-
-            // If advancing the current encoder failed, attempt to move to the next encoder.
-            if let Some(input) = self.inputs.first() {
-                *cur = input.witness.encoder();
-                if !cur.current_chunk().is_empty() {
-                    return EncoderStatus::HasMore;
-                }
-            } else {
-                self.cur_enc = None; // shortcut the next call to advance()
-                return EncoderStatus::Finished;
-            }
-        }
-    }
-}
-
 #[cfg(feature = "alloc")]
 encoding::encoder_newtype_exact! {
     /// The encoder for the [`TxIn`] type.