(DECODE_EMACS_MULE_COMPOSITION_CHAR): If coding->flags

is nonzero, accept multibyte form of eight-bit-control chars.
(decode_composition_emacs_mule): Likewise.
(decode_coding_emacs_mule): Likewise.
(encode_coding_emacs_mule): If coding->flags is nonzero, produce
multibyte form of eight-bit-control chars.

1 files changed, 29 insertions, 5 deletions

diff --git a/src/coding.c b/src/coding.c
index 584ad730903..2982dd3c86f 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -712,7 +712,7 @@ detect_coding_emacs_mule (src, src_end, multibytep)
 #define DECODE_EMACS_MULE_COMPOSITION_CHAR(c, p)                \
   do {                                                          \
     int bytes;                                                  \
-                                                                \
+                                                                \
     c = SAFE_ONE_MORE_BYTE ();                                  \
     if (c < 0)                                                  \
       break;                                                    \
@@ -743,7 +743,10 @@ detect_coding_emacs_mule (src, src_end, multibytep)
               break;                                            \
             *p++ = c;                                           \
           }                                                     \
-        if (UNIBYTE_STR_AS_MULTIBYTE_P (p0, p - p0, bytes))     \
+        if (UNIBYTE_STR_AS_MULTIBYTE_P (p0, p - p0, bytes)      \
+            || (coding->flags /* We are recovering a file.  */  \
+                && p0[0] == LEADING_CODE_8_BIT_CONTROL          \
+                && ! CHAR_HEAD_P (p0[1])))                      \
           c = STRING_CHAR (p0, bytes);                          \
         else                                                    \
           c = -1;                                               \
@@ -847,7 +850,10 @@ decode_composition_emacs_mule (coding, src, src_end,
           else
             {
               int bytes;
-              if (UNIBYTE_STR_AS_MULTIBYTE_P (src, src_end - src, bytes))
+              if (UNIBYTE_STR_AS_MULTIBYTE_P (src, src_end - src, bytes)
+                  || (coding->flags /* We are recovering a file.  */
+                      && src[0] == LEADING_CODE_8_BIT_CONTROL
+                      && ! CHAR_HEAD_P (src[1])))
                 c = STRING_CHAR (src, bytes);
               else
                 c = *src, bytes = 1;
@@ -1001,7 +1007,10 @@ decode_coding_emacs_mule (coding, source, destination, src_bytes, dst_bytes)
           p = tmp;
           src++;
         }
-      else if (UNIBYTE_STR_AS_MULTIBYTE_P (src, src_end - src, bytes))
+      else if (UNIBYTE_STR_AS_MULTIBYTE_P (src, src_end - src, bytes)
+               || (coding->flags /* We are recovering a file.  */
+                   && src[0] == LEADING_CODE_8_BIT_CONTROL
+                   && ! CHAR_HEAD_P (src[1])))
         {
           p = src;
           src += bytes;
@@ -1132,7 +1141,22 @@ encode_coding_emacs_mule (coding, source, destination, src_bytes, dst_bytes)
             EMIT_ONE_BYTE ('\r');
         }
       else if (SINGLE_BYTE_CHAR_P (c))
-        EMIT_ONE_BYTE (c);
+        {
+          if (coding->flags && ! ASCII_BYTE_P (c))
+            {
+              /* As we are auto saving, retain the multibyte form for
+                 8-bit chars.  */
+              unsigned char buf[MAX_MULTIBYTE_LENGTH];
+              int bytes = CHAR_STRING (c, buf);
+
+              if (bytes == 1)
+                EMIT_ONE_BYTE (buf[0]);
+              else
+                EMIT_TWO_BYTES (buf[0], buf[1]);
+            }
+          else
+            EMIT_ONE_BYTE (c);
+        }
       else
         EMIT_BYTES (src_base, src);
       coding->consumed_char++;