(casify_object): Scan string by bytes and chars.

Use make_multibyte_string.

1 files changed, 23 insertions, 7 deletions

diff --git a/src/casefiddle.c b/src/casefiddle.c
index 2ca61ab51ec..8768ad1fd8a 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -57,15 +57,19 @@ casify_object (flag, obj)
             }
           return obj;
         }
+
       if (STRINGP (obj))
         {
-          int multibyte = !NILP (current_buffer->enable_multibyte_characters);
+          int multibyte = STRING_MULTIBYTE (obj);
 
           obj = Fcopy_sequence (obj);
-          len = XSTRING (obj)->size;
-          for (i = 0; i < len; i++)
+          len = XSTRING (obj)->size_byte;
+
+          /* Scan all single-byte characters from start of string.  */
+          for (i = 0; i < len;)
             {
               c = XSTRING (obj)->data[i];
+
               if (multibyte && c >= 0x80)
                 /* A multibyte character can't be handled in this
                    simple loop.  */
@@ -75,15 +79,25 @@ casify_object (flag, obj)
               else if (!UPPERCASEP (c)
                        && (!inword || flag != CASE_CAPITALIZE_UP))
                 c = UPCASE1 (c);
+              /* If this char won't fit in a single-byte string.
+                 fall out to the multibyte case.  */
+              if (multibyte ? ! ASCII_BYTE_P (c)
+                  : ! SINGLE_BYTE_CHAR_P (c))
+                break;
+
               XSTRING (obj)->data[i] = c;
               if ((int) flag >= (int) CASE_CAPITALIZE)
                 inword = SYNTAX (c) == Sword;
+              i++;
             }
+
+          /* If we didn't do the whole string as single-byte,
+             scan the rest in a more complex way.  */
           if (i < len)
             {
               /* The work is not yet finished because of a multibyte
                  character just encountered.  */
-              int fromlen, tolen, j = i;
+              int fromlen, tolen, j = i, j_byte = i;
               char *buf
                 = (char *) alloca ((len - i) * MAX_LENGTH_OF_MULTI_BYTE_FORM
                                    + i);
@@ -92,6 +106,7 @@ casify_object (flag, obj)
               /* Copy data already handled.  */
               bcopy (XSTRING (obj)->data, buf, i);
 
+              /* From now on, I counts bytes.  */
               while (i < len)
                 {
                   c = STRING_CHAR_AND_LENGTH (XSTRING (obj)->data + i,
@@ -102,13 +117,14 @@ casify_object (flag, obj)
                            && (!inword || flag != CASE_CAPITALIZE_UP))
                     c = UPCASE1 (c);
                   tolen = CHAR_STRING (c, workbuf, str);
-                  bcopy (str, buf + j, tolen);
+                  bcopy (str, buf + j_byte, tolen);
                   i += fromlen;
-                  j += tolen;
+                  j++;
+                  j_byte += tolen;
                   if ((int) flag >= (int) CASE_CAPITALIZE)
                     inword = SYNTAX (c) == Sword;
                 }
-              obj = make_string (buf, j);
+              obj = make_multibyte_string (buf, j, j_byte);
             }
           return obj;
         }