+ CHECK_NUMBER (newelt);
+
+ if (XINT (newelt) < 0 || SINGLE_BYTE_CHAR_P (XINT (newelt)))
+ SSET (array, idxval, XINT (newelt));
+ else
+ {
+ /* We must relocate the string data while converting it to
+ multibyte. */
+ int idxval_byte, prev_bytes, new_bytes;
+ unsigned char workbuf[MAX_MULTIBYTE_LENGTH], *p0 = workbuf, *p1;
+ unsigned char *origstr = SDATA (array), *str;
+ int nchars, nbytes;
+
+ nchars = SCHARS (array);
+ nbytes = idxval_byte = count_size_as_multibyte (origstr, idxval);
+ nbytes += count_size_as_multibyte (origstr + idxval,
+ nchars - idxval);
+ str = (nbytes <= MAX_ALLOCA
+ ? (unsigned char *) alloca (nbytes)
+ : (unsigned char *) xmalloc (nbytes));
+ copy_text (SDATA (array), str, nchars, 0, 1);
+ PARSE_MULTIBYTE_SEQ (str + idxval_byte, nbytes - idxval_byte,
+ prev_bytes);
+ new_bytes = CHAR_STRING (XINT (newelt), p0);
+ allocate_string_data (XSTRING (array), nchars,
+ nbytes + new_bytes - prev_bytes);
+ bcopy (str, SDATA (array), idxval_byte);
+ p1 = SDATA (array) + idxval_byte;
+ while (new_bytes--)
+ *p1++ = *p0++;
+ bcopy (str + idxval_byte + prev_bytes, p1,
+ nbytes - (idxval_byte + prev_bytes));
+ if (nbytes > MAX_ALLOCA)
+ xfree (str);
+ clear_string_char_byte_cache ();
+ }