fix(text): include terminator length in empty text size

Co-authored-by: Serial <69764315+serial-ata@users.noreply.github.com>

Author: muja

CHANGELOG.md

@@ -51,9 +51,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * **FileResolver**: Replaced `FileResolver::supported_tag_types()` with `FileResolver::tag_support()` ([PR](https://github.com/Serial-ATA/lofty-rs/pull/566))
 
 ### Fixed
-- **ID3v2**: Support parsing UTF-16 `COMM`/`USLT` frames with a single BOM ([issue](https://github.com/Serial-ATA/lofty-rs/issues/532)) ([PR](https://github.com/Serial-ATA/lofty-rs/pull/535))
-  - Some encoders will only write a BOM to the frame's description, rather than to every string in the frame.
-    This was previously only supported in `SYLT` frames, and has been extended to `COMM` and `USLT`.
+- **ID3v2**:
+  - Support parsing UTF-16 `COMM`/`USLT` frames with a single BOM ([issue](https://github.com/Serial-ATA/lofty-rs/issues/532)) ([PR](https://github.com/Serial-ATA/lofty-rs/pull/535))
+    - Some encoders will only write a BOM to the frame's description, rather than to every string in the frame.
+      This was previously only supported in `SYLT` frames, and has been extended to `COMM` and `USLT`.
+  - Don't error on empty `SYLT` strings ([issue](https://github.com/Serial-ATA/lofty-rs/issues/563)) ([PR](https://github.com/Serial-ATA/lofty-rs/pull/564))
 - **Vorbis Comments**: Parse `TRACKNUMBER` with respect to `ParseOptions::implicit_conversions` ([issue](https://github.com/Serial-ATA/lofty-rs/issues/540)) ([PR](https://github.com/Serial-ATA/lofty-rs/issues/542))
 - **APE**: Fix disc number removal/writing ([issue](https://github.com/Serial-ATA/lofty-rs/issues/545)) ([PR](https://github.com/Serial-ATA/lofty-rs/pull/546))
 

lofty/src/util/text.rs

@@ -52,7 +52,7 @@ impl TextEncoding {
 	}
 }
 
-#[derive(Eq, PartialEq, Debug)]
+#[derive(Eq, PartialEq, Debug, Default)]
 pub(crate) struct DecodeTextResult {
 	pub(crate) content: String,
 	pub(crate) bytes_read: usize,
@@ -69,12 +69,6 @@ impl DecodeTextResult {
 	}
 }
 
-const EMPTY_DECODED_TEXT: DecodeTextResult = DecodeTextResult {
-	content: String::new(),
-	bytes_read: 0,
-	bom: [0, 0],
-};
-
 /// Specify how to decode the provided text
 ///
 /// By default, this will:
@@ -131,7 +125,10 @@ where
 		let (bytes, terminator_len) = read_to_terminator(reader, options.encoding);
 
 		if bytes.is_empty() {
-			return Ok(EMPTY_DECODED_TEXT);
+			return Ok(DecodeTextResult {
+				bytes_read: terminator_len,
+				..DecodeTextResult::default()
+			});
 		}
 
 		bytes_read = bytes.len() + terminator_len;
@@ -141,7 +138,7 @@ where
 		reader.read_to_end(&mut bytes)?;
 
 		if bytes.is_empty() {
-			return Ok(EMPTY_DECODED_TEXT);
+			return Ok(DecodeTextResult::default());
 		}
 
 		bytes_read = bytes.len();
@@ -402,6 +399,19 @@ mod tests {
 		)
 		.unwrap();
 
+		let empty_text_fragment = super::decode_text(
+			&mut Cursor::new(&[
+				0x00, 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+				0x00, 0x02,
+			]),
+			TextDecodeOptions::new()
+				.encoding(TextEncoding::UTF8)
+				.terminated(true),
+		)
+		.unwrap();
+		assert_eq!(empty_text_fragment.content, "");
+		assert_eq!(empty_text_fragment.bytes_read, 1);
+
 		assert_eq!(utf8_decode.content, TEST_STRING.to_string());
 	}