as_ref() before wrapping encoded types in writing option TLVs

We almost certainly don't want to be moving `option` TLVs during
serialization, and while we had logic elsewhere to work around this
previously its nice not to have to in the future.

Author: TheBlueMatt

lightning/src/ln/features.rs

@@ -81,6 +81,12 @@ macro_rules! impl_feature_write_without_length {
 			}
 		}
 
+		impl Writeable for WithoutLength<&&$features> {
+			fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+				write_be(w, self.0.le_flags())
+			}
+		}
+
 		impl Readable for WithoutLength<$features> {
 			fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 				let v = io_extras::read_to_end(r)?;

lightning/src/ln/msgs.rs

@@ -763,10 +763,10 @@ pub struct UpdateAddHTLC {
 
 struct AccountableBool<T>(T);
 
-impl Writeable for AccountableBool<bool> {
+impl Writeable for AccountableBool<&bool> {
 	#[inline]
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
-		let wire_value = if self.0 { 7u8 } else { 0u8 };
+		let wire_value = if *self.0 { 7u8 } else { 0u8 };
 		writer.write_all(&[wire_value])
 	}
 }

lightning/src/util/ser.rs

@@ -610,6 +610,13 @@ macro_rules! impl_writeable_primitive {
 				writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros() / 8) as usize..$len])
 			}
 		}
+		impl Writeable for HighZeroBytesDroppedBigSize<&$val_type> {
+			#[inline]
+			fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+				// Skip any full leading 0 bytes when writing (in BE):
+				writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros() / 8) as usize..$len])
+			}
+		}
 		impl Readable for $val_type {
 			#[inline]
 			fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
@@ -751,12 +758,20 @@ impl_array!(HMAC_LEN * HMAC_COUNT, u8);
 /// This is not exported to bindings users as manual TLV building is not currently supported in bindings
 pub struct WithoutLength<T>(pub T);
 
+impl Writeable for WithoutLength<&&String> {
+	#[inline]
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		w.write_all(self.0.as_bytes())
+	}
+}
+
 impl Writeable for WithoutLength<&String> {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 		w.write_all(self.0.as_bytes())
 	}
 }
+
 impl LengthReadable for WithoutLength<String> {
 	#[inline]
 	fn read_from_fixed_length_buffer<R: LengthLimitedRead>(r: &mut R) -> Result<Self, DecodeError> {
@@ -808,6 +823,14 @@ impl<T: Writeable> AsWriteableSlice for &Vec<T> {
 		&self
 	}
 }
+
+impl<T: Writeable> AsWriteableSlice for &&Vec<T> {
+	type Inner = T;
+	fn as_slice(&self) -> &[T] {
+		&self
+	}
+}
+
 impl<T: Writeable> AsWriteableSlice for &[T] {
 	type Inner = T;
 	fn as_slice(&self) -> &[T] {

lightning/src/util/ser_macros.rs

@@ -81,7 +81,7 @@ macro_rules! _encode_tlv {
 		$crate::_encode_tlv!($stream, $type, $field, option);
 	};
 	($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident) $(, $self: ident)?)) => {
-		$crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option);
+		$crate::_encode_tlv!($stream, $type, $field.as_ref().map(|f| $encoding(f)), option);
 	};
 	($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty) $(, $self: ident)?) => {
 		$crate::_encode_tlv!($stream, $type, $field, option);
@@ -253,8 +253,7 @@ macro_rules! _get_varint_length_prefixed_tlv_length {
 		$crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 	};
 	($len: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident)) $(, $self: ident)?) => {
-		let field = $field.map(|f| $encoding(f));
-		$crate::_get_varint_length_prefixed_tlv_length!($len, $type, field, option);
+		$crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field.as_ref().map(|f| $encoding(f)), option);
 	};
 	($len: expr, $type: expr, $field: expr, upgradable_required $(, $self: ident)?) => {
 		$crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required);