Commit cae184f2 authored by Kenichi Handa's avatar Kenichi Handa
Browse files

(count_combining_composition): New function.

(count_combining_before): Adjust the way to check byte-combining
possibility for the new handling of multibyte sequence.  Call
count_combining_composition for a composite character.
(count_combining_after): Likewise.
parent 1be6387d
......@@ -879,6 +879,33 @@ insert_1 (string, nbytes, inherit, prepare, before_markers)
inherit, prepare, before_markers);
}
/* See if the byte sequence at STR1 of length LEN1 combine with the
byte sequence at STR2 of length LEN2 to form a single composite
character. If so, return the number of bytes at the start of STR2
which combine in this way. Otherwise, return 0. If STR3 is not
NULL, it is a byte sequence of length LEN3 to be appended to STR1
before checking the combining. */
int
count_combining_composition (str1, len1, str2, len2, str3, len3)
unsigned char *str1, *str2, *str3;
int len1, len2, len3;
{
int len = len1 + len2 + len3;
unsigned char *buf = (unsigned char *) alloca (len + 1);
int bytes;
bcopy (str1, buf, len1);
if (str3)
{
bcopy (str3, buf + len1, len3);
len1 += len3;
}
bcopy (str2, buf + len1 , len2);
buf[len] = 0;
PARSE_MULTIBYTE_SEQ (buf, len, bytes);
return (bytes <= len1 ? 0 : bytes - len1);
}
/* See if the bytes before POS/POS_BYTE combine with bytes
at the start of STRING to form a single character.
If so, return the number of bytes at the start of STRING
......@@ -890,30 +917,44 @@ count_combining_before (string, length, pos, pos_byte)
int length;
int pos, pos_byte;
{
int opos = pos, opos_byte = pos_byte;
int c;
unsigned char *p = string;
int len, combining_bytes;
unsigned char *p;
if (NILP (current_buffer->enable_multibyte_characters))
return 0;
if (length == 0 || CHAR_HEAD_P (*string))
/* At first, we can exclude the following cases:
(1) STRING[0] can't be a following byte of multibyte sequence.
(2) POS is the start of the current buffer.
(3) A character before POS is not a multibyte character. */
if (length == 0 || CHAR_HEAD_P (*string)) /* case (1) */
return 0;
if (pos == BEG)
if (pos_byte == BEG_BYTE) /* case (2) */
return 0;
c = FETCH_BYTE (pos_byte - 1);
if (ASCII_BYTE_P (c))
len = 1;
p = BYTE_POS_ADDR (pos_byte - 1);
while (! CHAR_HEAD_P (*p)) p--, len++;
if (! BASE_LEADING_CODE_P (*p)) /* case (3) */
return 0;
DEC_BOTH (pos, pos_byte);
c = FETCH_BYTE (pos_byte);
if (! BASE_LEADING_CODE_P (c))
/* A sequence of a composite character requires a special handling. */
if (*p == LEADING_CODE_COMPOSITION)
return count_combining_composition (p, len, string, length, NULL, 0);
combining_bytes = BYTES_BY_CHAR_HEAD (*p) - len;
if (combining_bytes <= 0)
/* The character preceding POS is, complete and no room for
combining bytes (combining_bytes == 0), or an independent 8-bit
character (combining_bytes < 0). */
return 0;
/* We have a combination situation.
Count the bytes at STRING that will combine. */
/* We have a combination situation. Count the bytes at STRING that
may combine. */
p = string + 1;
while (!CHAR_HEAD_P (*p) && p < string + length)
p++;
return p - string;
return (combining_bytes < p - string ? combining_bytes : p - string);
}
/* See if the bytes after POS/POS_BYTE combine with bytes
......@@ -929,12 +970,25 @@ count_combining_after (string, length, pos, pos_byte)
{
int opos = pos, opos_byte = pos_byte;
int i;
int c;
int c, bytes;
unsigned char *bufp;
if (NILP (current_buffer->enable_multibyte_characters))
return 0;
if (length > 0 && ASCII_BYTE_P (string[length - 1]))
/* At first, we can exclude the following cases:
(1) The last byte of STRING is an ASCII.
(2) POS is the last of the current buffer.
(3) A character at POS can't be a following byte of multibyte
character. */
if (length > 0 && ASCII_BYTE_P (string[length - 1])) /* case (1) */
return 0;
if (pos_byte == Z_BYTE) /* case (2) */
return 0;
bufp = BYTE_POS_ADDR (pos_byte);
if (CHAR_HEAD_P (*bufp)) /* case (3) */
return 0;
i = length - 1;
while (i >= 0 && ! CHAR_HEAD_P (string[i]))
{
......@@ -942,33 +996,37 @@ count_combining_after (string, length, pos, pos_byte)
}
if (i < 0)
{
/* All characters in `string' are not character head.
We must check also preceding bytes at POS.
We are sure that the gap is at POS. */
string = BEG_ADDR;
/* All characters in STRING are not character head. We must
check also preceding bytes at POS. We are sure that the gap
is at POS. */
unsigned char *p = BEG_ADDR;
i = pos_byte - 2;
while (i >= 0 && ! CHAR_HEAD_P (string[i]))
while (i >= 0 && ! CHAR_HEAD_P (p[i]))
i--;
if (i < 0 || !BASE_LEADING_CODE_P (string[i]))
if (i < 0 || !BASE_LEADING_CODE_P (p[i]))
return 0;
/* A sequence of a composite character requires a special handling. */
if (p[i] == LEADING_CODE_COMPOSITION)
return count_combining_composition (p + i, pos_byte - 1 - i,
bufp, Z_BYTE - pos_byte,
string, length);
bytes = BYTES_BY_CHAR_HEAD (p[i]);
return (bytes <= pos_byte - 1 - i + length
? 0
: bytes - (pos_byte - 1 - i + length));
}
else if (!BASE_LEADING_CODE_P (string[i]))
if (!BASE_LEADING_CODE_P (string[i]))
return 0;
/* A sequence of a composite character requires a special handling. */
if (string[i] == LEADING_CODE_COMPOSITION)
return count_combining_composition (string + i, length - i,
bufp, Z_BYTE - pos_byte, NULL, 0);
if (pos == Z)
return 0;
c = FETCH_BYTE (pos_byte);
if (CHAR_HEAD_P (c))
return 0;
while (pos_byte < Z_BYTE)
{
c = FETCH_BYTE (pos_byte);
if (CHAR_HEAD_P (c))
break;
pos_byte++;
}
bytes = BYTES_BY_CHAR_HEAD (string[i]) - (length - i);
bufp++, pos_byte++;
while (!CHAR_HEAD_P (*bufp)) bufp++, pos_byte++;
return pos_byte - opos_byte;
return (bytes <= pos_byte - opos_byte ? bytes : pos_byte - opos_byte);
}
/* Adjust the position TARGET/TARGET_BYTE for the combining of NBYTES
......
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