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| | /* Check UTF-8 string.
Copyright (C) 2002, 2006-2007, 2009-2017 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2002.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include "unistr.h"
const uint8_t *
u8_check (const uint8_t *s, size_t n)
{
const uint8_t *s_end = s + n;
while (s < s_end)
{
/* Keep in sync with unistr.h and u8-mbtouc-aux.c. */
uint8_t c = *s;
if (c < 0x80)
{
s++;
continue;
}
if (c >= 0xc2)
{
if (c < 0xe0)
{
if (s + 2 <= s_end
&& (s[1] ^ 0x80) < 0x40)
{
s += 2;
continue;
}
}
else if (c < 0xf0)
{
if (s + 3 <= s_end
&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (c >= 0xe1 || s[1] >= 0xa0)
&& (c != 0xed || s[1] < 0xa0))
{
s += 3;
continue;
}
}
else if (c < 0xf8)
{
if (s + 4 <= s_end
&& (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
&& (s[3] ^ 0x80) < 0x40
&& (c >= 0xf1 || s[1] >= 0x90)
&& (c < 0xf4 || (c == 0xf4 && s[1] < 0x90)))
{
s += 4;
continue;
}
}
}
/* invalid or incomplete multibyte character */
return s;
}
return NULL;
}
|