+
+#if defined (HANDLE_MULTIBYTE)
+/* Calculate the number of screen columns occupied by STR from START to END.
+ In the case of multibyte characters with stateful encoding, we have to
+ scan from the beginning of the string to take the state into account. */
+static int
+_rl_col_width (str, start, end, flags)
+ const char *str;
+ int start, end, flags;
+{
+ wchar_t wc;
+ mbstate_t ps;
+ int tmp, point, width, max;
+
+ if (end <= start)
+ return 0;
+ if (MB_CUR_MAX == 1 || rl_byte_oriented)
+{
+_rl_ttymsg ("_rl_col_width: called with MB_CUR_MAX == 1");
+ return (end - start);
+}
+
+ memset (&ps, 0, sizeof (mbstate_t));
+
+ point = 0;
+ max = end;
+
+ /* Try to short-circuit common cases. The adjustment to remove wrap_offset
+ is done by the caller. */
+ /* 1. prompt string */
+ if (flags && start == 0 && end == local_prompt_len && memcmp (str, local_prompt, local_prompt_len) == 0)
+ return (prompt_physical_chars + wrap_offset);
+ /* 2. prompt string + line contents */
+ else if (flags && start == 0 && local_prompt_len > 0 && end > local_prompt_len && local_prompt && memcmp (str, local_prompt, local_prompt_len) == 0)
+ {
+ tmp = prompt_physical_chars + wrap_offset;
+ /* XXX - try to call ourselves recursively with non-prompt portion */
+ tmp += _rl_col_width (str, local_prompt_len, end, flags);
+ return (tmp);
+ }
+
+ while (point < start)
+ {
+ tmp = mbrlen (str + point, max, &ps);
+ if (MB_INVALIDCH ((size_t)tmp))
+ {
+ /* In this case, the bytes are invalid or too short to compose a
+ multibyte character, so we assume that the first byte represents
+ a single character. */
+ point++;
+ max--;
+
+ /* Clear the state of the byte sequence, because in this case the
+ effect of mbstate is undefined. */
+ memset (&ps, 0, sizeof (mbstate_t));
+ }
+ else if (MB_NULLWCH (tmp))
+ break; /* Found '\0' */
+ else
+ {
+ point += tmp;
+ max -= tmp;
+ }
+ }
+
+ /* If START is not a byte that starts a character, then POINT will be
+ greater than START. In this case, assume that (POINT - START) gives
+ a byte count that is the number of columns of difference. */
+ width = point - start;
+
+ while (point < end)
+ {
+ tmp = mbrtowc (&wc, str + point, max, &ps);
+ if (MB_INVALIDCH ((size_t)tmp))
+ {
+ /* In this case, the bytes are invalid or too short to compose a
+ multibyte character, so we assume that the first byte represents
+ a single character. */
+ point++;
+ max--;
+
+ /* and assume that the byte occupies a single column. */
+ width++;
+
+ /* Clear the state of the byte sequence, because in this case the
+ effect of mbstate is undefined. */
+ memset (&ps, 0, sizeof (mbstate_t));
+ }
+ else if (MB_NULLWCH (tmp))
+ break; /* Found '\0' */
+ else
+ {
+ point += tmp;
+ max -= tmp;
+ tmp = wcwidth(wc);
+ width += (tmp >= 0) ? tmp : 1;
+ }
+ }
+
+ width += point - end;
+
+ return width;
+}
+#endif /* HANDLE_MULTIBYTE */