fix: xim-ctext: Fix decode macro to track bytes

In current implementation of decode! macro, length of bytes read
returned by encoding_rs::Decoder::decode_to_string is not used,
causing early part of japanese string to be repeated.
This commit fixes invalid behavior by using previously mentioned length
value to prevent decoding certain part of bytes multiple times.

Signed-off-by: npmania <[email protected]>

Author: npmania

xim-ctext/src/lib.rs

@@ -100,8 +100,9 @@ impl fmt::Display for DecodeError {
 
 macro_rules! decode {
     ($decoder:expr, $out:expr, $bytes:expr, $last:expr) => {
+        let mut _current_bytes: &[u8] = $bytes;
         loop {
-            let (ret, _, _) = $decoder.decode_to_string($bytes, $out, $last);
+            let (ret, nread, _) = $decoder.decode_to_string(_current_bytes, $out, $last);
 
             match ret {
                 encoding_rs::CoderResult::InputEmpty => break,
@@ -111,6 +112,7 @@ macro_rules! decode {
                             .max_utf8_buffer_length($bytes.len())
                             .unwrap_or_default(),
                     );
+                    _current_bytes = &_current_bytes[nread..];
                 }
             }
         }
@@ -271,7 +273,7 @@ mod tests {
     }
 
     #[test]
-    fn iso_2011_jp() {
+    fn iso_2022_jp() {
         const UTF8: &str = "東京";
         const COMP: &[u8] = &[27, 36, 40, 66, 69, 108, 53, 126];
         assert_eq!(crate::compound_text_to_utf8(COMP).unwrap(), UTF8);
@@ -318,4 +320,13 @@ mod tests {
         const COMP: &[u8] = &[0x1b, 0x2d, 0x42, 0xa1, 0xa3, 0xa5, 0xa6, 0xa9, 0xab];
         assert_eq!(crate::compound_text_to_utf8(COMP).unwrap(), UTF8);
     }
+
+    #[test]
+    fn iso_2022_jp_long() {
+        const UTF8: &str = "知ってるつもり";
+        const COMP: &[u8] = &[
+            27, 36, 40, 66, 67, 78, 36, 67, 36, 70, 36, 107, 36, 68, 36, 98, 36, 106, 27, 40, 66,
+        ];
+        assert_eq!(crate::compound_text_to_utf8(COMP).unwrap(), UTF8);
+    }
 }