1/* Look at first character in UTF-16 string.
2   Copyright (C) 1999-2000, 2002, 2006-2007, 2009-2010 Free Software
3   Foundation, Inc.
4   Written by Bruno Haible <bruno@clisp.org>, 2002.
5
6   This program is free software: you can redistribute it and/or modify it
7   under the terms of the GNU Lesser General Public License as published
8   by the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15
16   You should have received a copy of the GNU Lesser General Public License
17   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18
19#include <config.h>
20
21/* Specification.  */
22#include "unistr.h"
23
24int
25u16_strmbtouc (ucs4_t *puc, const uint16_t *s)
26{
27  /* Keep in sync with unistr.h and utf16-ucs4.c.  */
28  uint16_t c = *s;
29
30  if (c < 0xd800 || c >= 0xe000)
31    {
32      *puc = c;
33      return (c != 0 ? 1 : 0);
34    }
35#if CONFIG_UNICODE_SAFETY
36  if (c < 0xdc00)
37#endif
38    {
39#if CONFIG_UNICODE_SAFETY
40      if (s[1] >= 0xdc00 && s[1] < 0xe000)
41#else
42      if (s[1] != 0)
43#endif
44        {
45          *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
46          return 2;
47        }
48    }
49  /* invalid or incomplete multibyte character */
50  return -1;
51}
52