* iconv/gconv_int.h (__GCONV_NULCONV): New internal only error code.

	* iconv/gconv_cache.c (__gconv_lookup_cache): Return __GCONV_NULCONV
	if from and to charsets are the same.
	* iconv/gconv_db.c (__gconv_find_transform): Likewise.
	* intl/dcigettext.c (_nl_find_msg): Return NULL even if __gconv_open
	returns __GCONV_NOCONV, but not for __GCONV_NULCONV.

2007-07-17  Jakub Jelinek  <jakub@redhat.com>

	* wcsmbs/wchar.h: Only define wint_t if __need_wint_t.
	Don't define wint_t when __need_mbstate_t unless it
	is necessary.
	(__mbstate_t): Use __WINT_TYPE__ rather than wint_t
	in the typedef if possible.
	* wctype/wctype.h (wint_t): Define by including
	wchar.h with __need_wint_t instead of including stddef.h
	with __need_wint_t and as fallback definining it ourselves.
	* iconv/gconv.h (__need_wint_t): Define before including
	wchar.h.
	* sysdeps/gnu/_G_config.h: Don't include gconv.h if not _LIBC
	or _GLIBCPP_USE_WCHAR_T.
	(__need_wchar_t): Don't define
	if not _LIBC or _GLIBCPP_USE_WCHAR_T.
	(__need_wint_t): Don't define before including stddef.h,
	define before including wchar.h only if _LIBC or
	_GLIBCPP_USE_WCHAR_T.
	(_G_iconv_t): Don't define if not _LIBC or _GLIBCPP_USE_WCHAR_T.
	* sysdeps/mach/hurd/_G_config.h: Likewise.
	* sysdeps/generic/_G_config.h: Likewise.
	* libio/libio.h (__wunderflow, __wuflow, __woverflow): Only
	prototype if _LIBC or _GLIBCPP_USE_WCHAR_T.
	(_IO_getwc_unlocked, _IO_putwc_unlocked): Only define
	if _LIBC or _GLIBCPP_USE_WCHAR_T.