/***
*mbscat_s.inl - general implementation of _mbsncat_s and _mbsnbcat_s
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* This file contains the general algorithm for _mbsncat_s and _mbsnbcat_s.
*
****/
_FUNC_PROLOGUE
#if _USE_LOCALE_ARG
errno_t __cdecl _FUNC_NAME(unsigned char *_DEST, size_t _SizeInBytes, const unsigned char *_SRC, size_t _COUNT, _LOCALE_ARG_DECL)
#else /* _USE_LOCALE_ARG */
errno_t __cdecl _FUNC_NAME(unsigned char *_DEST, size_t _SizeInBytes, const unsigned char *_SRC, size_t _COUNT)
#endif /* _USE_LOCALE_ARG */
{
unsigned char *p;
size_t available;
BOOL fIsLeadPrefix;
BOOL fFoundInvalidMBC;
fFoundInvalidMBC = FALSE;
if (_COUNT == 0 && _DEST == NULL && _SizeInBytes == 0)
{
/* this case is allowed; nothing to do */
_RETURN_NO_ERROR;
}
/* validation section */
_VALIDATE_STRING(_DEST, _SizeInBytes);
if (_COUNT != 0)
{
_VALIDATE_POINTER_RESET_STRING(_SRC, _DEST, _SizeInBytes);
}
#if _USE_LOCALE_ARG
_LOCALE_UPDATE;
if (_LOCALE_SHORTCUT_TEST)
{
return _SB_FUNC_NAME((char *)_DEST, _SizeInBytes, (const char *)_SRC, _COUNT);
}
#endif /* _USE_LOCALE_ARG */
p = _DEST;
available = _SizeInBytes;
while (available > 0 && *p != 0)
{
p++;
available--;
}
/*
* Ran out of room while looking for end of dst string.
* p points 1 past end of buffer. We can't look past
* end of buffer so can't tell if dst ended with an
* invalid mbc.
*/
if (available == 0)
{
_RESET_STRING(_DEST, _SizeInBytes);
_RETURN_DEST_NOT_NULL_TERMINATED(_DEST, _SizeInBytes);
}
if (available < _SizeInBytes)
{
/*
* Dst may have terminated with an invalid MBCS, in that case we clear
* the bogus lead byte.
*/
fIsLeadPrefix = FALSE;
_ISMBBLEADPREFIX(fIsLeadPrefix, _DEST, &p[-1]);
if (fIsLeadPrefix) {
/* the original string ended with a lead byte: we remove it */
p--;
*p = 0;
available++;
fFoundInvalidMBC = TRUE;
}
}
if (_COUNT == _TRUNCATE)
{
while ((*p++ = *_SRC++) != 0 && --available > 0)
{
}
}
else
{
_ASSERT_EXPR((!_CrtGetCheckCount() || _COUNT < available), L"Buffer is too small");
#if _COUNT_IN_BYTES
while (_COUNT > 0 && (*p++ = *_SRC++) != 0 && --available > 0)
{
_COUNT--;
}
#else /* _COUNT_IN_BYTES */
while (_COUNT > 0)
{
if (_ISMBBLEAD(*_SRC))
{
if (_SRC[1] == 0)
{
/* the source string ended with a lead byte: we remove it */
*p = 0;
fFoundInvalidMBC = TRUE;
break;
}
if (available {
/* not enough space */
available = 0;
break;
}
*p++ = *_SRC++;
*p++ = *_SRC++;
available -= 2;
}
else
{
if ((*p++ = *_SRC++) == 0 || --available == 0)
{
break;
}
}
_COUNT--;
}
#endif /* _COUNT_IN_BYTES */
if (_COUNT == 0)
{
*p++ = 0;
}
}
if (available == 0)
{
#if _COUNT_IN_BYTES
/*
* defined(_COUNT_IN_BYTES) loop does not track mbc context,
* so we must iterate backwards to discover character context.
*/
if (*_SRC == 0 || _COUNT == 1)
{
_ISMBBLEADPREFIX(fIsLeadPrefix, _DEST, &p[-1]);
if (fIsLeadPrefix)
{
/* the source string ended with a lead byte: we remove it */
p[-1] = 0;
_RETURN_MBCS_ERROR;
}
}
#endif /* _COUNT_IN_BYTES */
/*
* _COUNT == _TRUNCATE loop terminated because available became 0.
* This means that we copied at least one character, and it wasn't
* a null. If this last character acted as a lead then overwrite
* it with null. Do not set the mbcs error in this case, due that the
* user cannot predict this case and he/she's only asking for truncation.
*/
if (_COUNT == _TRUNCATE)
{
if (fFoundInvalidMBC)
{
_SET_MBCS_ERROR;
}
if (_SizeInBytes > 1)
{
fIsLeadPrefix = FALSE;
_ISMBBLEADPREFIX(fIsLeadPrefix, _DEST, &_DEST[_SizeInBytes - 2]);
if (fIsLeadPrefix)
{
_DEST[_SizeInBytes - 2] = 0;
_FILL_BYTE(_DEST[_SizeInBytes - 1]);
_RETURN_TRUNCATE;
}
}
_DEST[_SizeInBytes - 1] = 0;
_RETURN_TRUNCATE;
}
_RESET_STRING(_DEST, _SizeInBytes);
_RETURN_BUFFER_TOO_SMALL(_DEST, _SizeInBytes);
}
#if _COUNT_IN_BYTES
if (available < _SizeInBytes)
{
_ISMBBLEADPREFIX(fIsLeadPrefix, _DEST, &p[-2]);
if (fIsLeadPrefix)
{
/* the source string ended with a lead byte: we remove it */
p[-2] = 0;
available++;
fFoundInvalidMBC = TRUE;
}
}
#endif /* _COUNT_IN_BYTES */
_FILL_STRING(_DEST, _SizeInBytes, _SizeInBytes - available + 1);
if (fFoundInvalidMBC)
{
_RETURN_MBCS_ERROR;
}
_RETURN_NO_ERROR;
}
