windows-xp/Source/XPSP1/NT/com/ole32/common/cruntime/chicago/towlower.c

/***
*towlower.c - convert wide character to lower case
*
*	Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	Defines towlower().
*
*Revision History:
*	10-11-91  ETC	Created.
*	12-10-91  ETC	Updated nlsapi; added multithread.
*	04-06-92  KRS	Make work without _INTL also.
*       01-19-93  CFW   Changed LCMapString to LCMapStringW.
*       06-02-93  SRW   ignore _INTL if _NTSUBSET_ defined.
*	06-11-93  CFW	Fix error handling bug.
*
*******************************************************************************/

#include <windows.h>
#include <cruntime.h>

/***
*wchar_t towlower(c) - convert wide character to lower case
*
*Purpose:
*	towlower() returns the lowercase equivalent of its argument
*
*Entry:
*	c - wchar_t value of character to be converted
*
*Exit:
*	if c is an upper case letter, returns wchar_t value of lower case
*	representation of c. otherwise, it returns c.
*
*Exceptions:
*
*******************************************************************************/

wchar_t _CALLTYPE1 towlower (
	wchar_t c
 	)
{

    //  If we're in the first 128 characters, it's just ANSII...

    if (c < 128) {
	return (wchar_t)CharLowerA((LPSTR)c);
    } else {
	WCHAR wBuffer[2];
	CHAR Buffer[8];
	int Length;
	BOOL fDefaultChar;

	wBuffer[0] = c;
	Length = WideCharToMultiByte (CP_ACP, WC_COMPOSITECHECK, wBuffer, 1, Buffer, sizeof (Buffer), NULL, &fDefaultChar);
	if (fDefaultChar == FALSE)
	{
	    Buffer[Length] = '\0';
	    CharLowerA (Buffer);
	    MultiByteToWideChar (CP_ACP, MB_PRECOMPOSED, Buffer, Length, wBuffer, 1);
	}
	return wBuffer[0];
    }

}