1  /* Conversion UTF-16 to UCS-4.
       2     Copyright (C) 2001-2002, 2006-2007, 2009-2023 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 2001.
       4  
       5     This file is free software.
       6     It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
       7     You can redistribute it and/or modify it under either
       8       - the terms of the GNU Lesser General Public License as published
       9         by the Free Software Foundation, either version 3, or (at your
      10         option) any later version, or
      11       - the terms of the GNU General Public License as published by the
      12         Free Software Foundation; either version 2, or (at your option)
      13         any later version, or
      14       - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
      15  
      16     This file is distributed in the hope that it will be useful,
      17     but WITHOUT ANY WARRANTY; without even the implied warranty of
      18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      19     Lesser General Public License and the GNU General Public License
      20     for more details.
      21  
      22     You should have received a copy of the GNU Lesser General Public
      23     License and of the GNU General Public License along with this
      24     program.  If not, see <https://www.gnu.org/licenses/>.  */
      25  
      26  #include <config.h>
      27  
      28  /* Specification.  */
      29  #include "unistr.h"
      30  
      31  #if defined IN_LIBUNISTRING || HAVE_INLINE
      32  
      33  int
      34  u16_mbtouc_aux (ucs4_t *puc, const uint16_t *s, size_t n)
      35  {
      36    uint16_t c = *s;
      37  
      38    if (c < 0xdc00)
      39      {
      40        if (n >= 2)
      41          {
      42            if (s[1] >= 0xdc00 && s[1] < 0xe000)
      43              {
      44                *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
      45                return 2;
      46              }
      47            /* invalid multibyte character */
      48          }
      49        else
      50          {
      51            /* incomplete multibyte character */
      52          }
      53      }
      54    /* invalid multibyte character */
      55    *puc = 0xfffd;
      56    return 1;
      57  }
      58  
      59  #endif