view lib/wcsncmp-impl.h @ 40212:8da9577294da

unistr/*, uniconv/*: Fix undefined behaviour. Reported by Jeffrey Walton <noloader@gmail.com>. * lib/unistr/u-cpy.h (FUNC): Don't invoke memcpy with a zero size. * lib/unistr/u-cpy-alloc.h (FUNC): Likewise. * lib/uniconv/u8-conv-from-enc.c (u8_conv_from_encoding): Likewise. * lib/uniconv/u8-conv-to-enc.c (u8_conv_to_encoding): Likewise.
author Bruno Haible <bruno@clisp.org>
date Sat, 09 Mar 2019 00:01:47 +0100
parents b06060465f09
children
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/* Compare two wide strings.
   Copyright (C) 1999, 2011-2019 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 1999.

   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/>.  */

int
wcsncmp (const wchar_t *s1, const wchar_t *s2, size_t n)
{
  for (; n > 0;)
    {
      wchar_t wc1 = *s1++;
      wchar_t wc2 = *s2++;
      if (wc1 != (wchar_t)'\0' && wc1 == wc2)
        {
          n--;
          continue;
        }
      /* Note that wc1 and wc2 each have at most 31 bits.  */
      return (int)wc1 - (int)wc2;
             /* > 0 if wc1 > wc2, < 0 if wc1 < wc2,
                = 0 if wc1 and wc2 are both '\0'.  */
    }
  return 0;
}