Fix Dired display and operations on file names with raw bytes

* src/coding.c (decode_coding): When flushing remaining raw bytes
from multibyte text, copy 2-byte forms of eight-bit-*
characters as single characters, not as 2 raw bytes.  (Bug#29189)

1 files changed, 16 insertions, 3 deletions

diff --git a/src/coding.c b/src/coding.c
index 35f85052c98..a7b040e2712 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -7423,10 +7423,23 @@ decode_coding (struct coding_system *coding)
 
           while (nbytes-- > 0)
             {
-              int c = *src++;
+              int c;
 
-              if (c & 0x80)
-                c = BYTE8_TO_CHAR (c);
+              /* Copy raw bytes in their 2-byte forms from multibyte
+                 text as single characters.  */
+              if (coding->src_multibyte
+                  && CHAR_BYTE8_HEAD_P (*src) && nbytes > 0)
+                {
+                  c = STRING_CHAR_ADVANCE (src);
+                  nbytes--;
+                }
+              else
+                {
+                  c = *src++;
+
+                  if (c & 0x80)
+                    c = BYTE8_TO_CHAR (c);
+                }
               coding->charbuf[coding->charbuf_used++] = c;
             }
           produce_chars (coding, Qnil, 1);