view src/bufwrite.c @ 34021:46ebf4ffad49 v9.0.2186

patch 9.0.2186: LTCG compile error ARM64 for write_chars Commit: https://github.com/vim/vim/commit/38bea30f53da8e4a8847407404597b255b20334e Author: Saleem Abdulrasool <compnerd@compnerd.org> Date: Wed Dec 27 18:57:12 2023 +0100 patch 9.0.2186: LTCG compile error ARM64 for write_chars Problem: LTCG compile error on Win/ARM64 for `write_chars()` Solution: Explicitly initialise the storage to use data rather than BSS (Saleem Abdulrasool) win32: add a workaround for a LTCG issue on Windows ARM64 It appears that the implicit initialisation which would push `g_coords` into BSS causes an aliasing issue with LTCG on ARM64. By explicitly initialising the value, we use usual data storage but prevent the aliasing. This allows the console version of VIM to run on Windows ARM64 again. fixes: #13453 closes: #13775 Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org> Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Wed, 27 Dec 2023 19:15:03 +0100
parents dcfbfe57141c
children 34a2b628cba5
line wrap: on
line source

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * bufwrite.c: functions for writing a buffer
 */

#include "vim.h"

#if defined(HAVE_UTIME) && defined(HAVE_UTIME_H)
# include <utime.h>		// for struct utimbuf
#endif

#define SMALLBUFSIZE	256	// size of emergency write buffer

/*
 * Structure to pass arguments from buf_write() to buf_write_bytes().
 */
struct bw_info
{
    int		bw_fd;		// file descriptor
    char_u	*bw_buf;	// buffer with data to be written
    int		bw_len;		// length of data
    int		bw_flags;	// FIO_ flags
#ifdef FEAT_CRYPT
    buf_T	*bw_buffer;	// buffer being written
    int		bw_finish;	// finish encrypting
#endif
    char_u	bw_rest[CONV_RESTLEN]; // not converted bytes
    int		bw_restlen;	// nr of bytes in bw_rest[]
    int		bw_first;	// first write call
    char_u	*bw_conv_buf;	// buffer for writing converted chars
    size_t	bw_conv_buflen; // size of bw_conv_buf
    int		bw_conv_error;	// set for conversion error
    linenr_T	bw_conv_error_lnum;  // first line with error or zero
    linenr_T	bw_start_lnum;	// line number at start of buffer
#ifdef USE_ICONV
    iconv_t	bw_iconv_fd;	// descriptor for iconv() or -1
#endif
};

/*
 * Convert a Unicode character to bytes.
 * Return TRUE for an error, FALSE when it's OK.
 */
    static int
ucs2bytes(
    unsigned	c,		// in: character
    char_u	**pp,		// in/out: pointer to result
    int		flags)		// FIO_ flags
{
    char_u	*p = *pp;
    int		error = FALSE;
    int		cc;


    if (flags & FIO_UCS4)
    {
	if (flags & FIO_ENDIAN_L)
	{
	    *p++ = c;
	    *p++ = (c >> 8);
	    *p++ = (c >> 16);
	    *p++ = (c >> 24);
	}
	else
	{
	    *p++ = (c >> 24);
	    *p++ = (c >> 16);
	    *p++ = (c >> 8);
	    *p++ = c;
	}
    }
    else if (flags & (FIO_UCS2 | FIO_UTF16))
    {
	if (c >= 0x10000)
	{
	    if (flags & FIO_UTF16)
	    {
		// Make two words, ten bits of the character in each.  First
		// word is 0xd800 - 0xdbff, second one 0xdc00 - 0xdfff
		c -= 0x10000;
		if (c >= 0x100000)
		    error = TRUE;
		cc = ((c >> 10) & 0x3ff) + 0xd800;
		if (flags & FIO_ENDIAN_L)
		{
		    *p++ = cc;
		    *p++ = ((unsigned)cc >> 8);
		}
		else
		{
		    *p++ = ((unsigned)cc >> 8);
		    *p++ = cc;
		}
		c = (c & 0x3ff) + 0xdc00;
	    }
	    else
		error = TRUE;
	}
	if (flags & FIO_ENDIAN_L)
	{
	    *p++ = c;
	    *p++ = (c >> 8);
	}
	else
	{
	    *p++ = (c >> 8);
	    *p++ = c;
	}
    }
    else    // Latin1
    {
	if (c >= 0x100)
	{
	    error = TRUE;
	    *p++ = 0xBF;
	}
	else
	    *p++ = c;
    }

    *pp = p;
    return error;
}

/*
 * Call write() to write a number of bytes to the file.
 * Handles encryption and 'encoding' conversion.
 *
 * Return FAIL for failure, OK otherwise.
 */
    static int
buf_write_bytes(struct bw_info *ip)
{
    int		wlen;
    char_u	*buf = ip->bw_buf;	// data to write
    int		len = ip->bw_len;	// length of data
    int		flags = ip->bw_flags;	// extra flags

    // Skip conversion when writing the crypt magic number or the BOM.
    if (!(flags & FIO_NOCONVERT))
    {
	char_u		*p;
	unsigned	c;
	int		n;

	if (flags & FIO_UTF8)
	{
	    // Convert latin1 in the buffer to UTF-8 in the file.
	    p = ip->bw_conv_buf;	// translate to buffer
	    for (wlen = 0; wlen < len; ++wlen)
		p += utf_char2bytes(buf[wlen], p);
	    buf = ip->bw_conv_buf;
	    len = (int)(p - ip->bw_conv_buf);
	}
	else if (flags & (FIO_UCS4 | FIO_UTF16 | FIO_UCS2 | FIO_LATIN1))
	{
	    // Convert UTF-8 bytes in the buffer to UCS-2, UCS-4, UTF-16 or
	    // Latin1 chars in the file.
	    if (flags & FIO_LATIN1)
		p = buf;	// translate in-place (can only get shorter)
	    else
		p = ip->bw_conv_buf;	// translate to buffer
	    for (wlen = 0; wlen < len; wlen += n)
	    {
		if (wlen == 0 && ip->bw_restlen != 0)
		{
		    int		l;

		    // Use remainder of previous call.  Append the start of
		    // buf[] to get a full sequence.  Might still be too
		    // short!
		    l = CONV_RESTLEN - ip->bw_restlen;
		    if (l > len)
			l = len;
		    mch_memmove(ip->bw_rest + ip->bw_restlen, buf, (size_t)l);
		    n = utf_ptr2len_len(ip->bw_rest, ip->bw_restlen + l);
		    if (n > ip->bw_restlen + len)
		    {
			// We have an incomplete byte sequence at the end to
			// be written.  We can't convert it without the
			// remaining bytes.  Keep them for the next call.
			if (ip->bw_restlen + len > CONV_RESTLEN)
			    return FAIL;
			ip->bw_restlen += len;
			break;
		    }
		    if (n > 1)
			c = utf_ptr2char(ip->bw_rest);
		    else
			c = ip->bw_rest[0];
		    if (n >= ip->bw_restlen)
		    {
			n -= ip->bw_restlen;
			ip->bw_restlen = 0;
		    }
		    else
		    {
			ip->bw_restlen -= n;
			mch_memmove(ip->bw_rest, ip->bw_rest + n,
						      (size_t)ip->bw_restlen);
			n = 0;
		    }
		}
		else
		{
		    n = utf_ptr2len_len(buf + wlen, len - wlen);
		    if (n > len - wlen)
		    {
			// We have an incomplete byte sequence at the end to
			// be written.  We can't convert it without the
			// remaining bytes.  Keep them for the next call.
			if (len - wlen > CONV_RESTLEN)
			    return FAIL;
			ip->bw_restlen = len - wlen;
			mch_memmove(ip->bw_rest, buf + wlen,
						      (size_t)ip->bw_restlen);
			break;
		    }
		    if (n > 1)
			c = utf_ptr2char(buf + wlen);
		    else
			c = buf[wlen];
		}

		if (ucs2bytes(c, &p, flags) && !ip->bw_conv_error)
		{
		    ip->bw_conv_error = TRUE;
		    ip->bw_conv_error_lnum = ip->bw_start_lnum;
		}
		if (c == NL)
		    ++ip->bw_start_lnum;
	    }
	    if (flags & FIO_LATIN1)
		len = (int)(p - buf);
	    else
	    {
		buf = ip->bw_conv_buf;
		len = (int)(p - ip->bw_conv_buf);
	    }
	}

#ifdef MSWIN
	else if (flags & FIO_CODEPAGE)
	{
	    // Convert UTF-8 or codepage to UCS-2 and then to MS-Windows
	    // codepage.
	    char_u	*from;
	    size_t	fromlen;
	    char_u	*to;
	    int		u8c;
	    BOOL	bad = FALSE;
	    int		needed;

	    if (ip->bw_restlen > 0)
	    {
		// Need to concatenate the remainder of the previous call and
		// the bytes of the current call.  Use the end of the
		// conversion buffer for this.
		fromlen = len + ip->bw_restlen;
		from = ip->bw_conv_buf + ip->bw_conv_buflen - fromlen;
		mch_memmove(from, ip->bw_rest, (size_t)ip->bw_restlen);
		mch_memmove(from + ip->bw_restlen, buf, (size_t)len);
	    }
	    else
	    {
		from = buf;
		fromlen = len;
	    }

	    to = ip->bw_conv_buf;
	    if (enc_utf8)
	    {
		// Convert from UTF-8 to UCS-2, to the start of the buffer.
		// The buffer has been allocated to be big enough.
		while (fromlen > 0)
		{
		    n = (int)utf_ptr2len_len(from, (int)fromlen);
		    if (n > (int)fromlen)	// incomplete byte sequence
			break;
		    u8c = utf_ptr2char(from);
		    *to++ = (u8c & 0xff);
		    *to++ = (u8c >> 8);
		    fromlen -= n;
		    from += n;
		}

		// Copy remainder to ip->bw_rest[] to be used for the next
		// call.
		if (fromlen > CONV_RESTLEN)
		{
		    // weird overlong sequence
		    ip->bw_conv_error = TRUE;
		    return FAIL;
		}
		mch_memmove(ip->bw_rest, from, fromlen);
		ip->bw_restlen = (int)fromlen;
	    }
	    else
	    {
		// Convert from enc_codepage to UCS-2, to the start of the
		// buffer.  The buffer has been allocated to be big enough.
		ip->bw_restlen = 0;
		needed = MultiByteToWideChar(enc_codepage,
			     MB_ERR_INVALID_CHARS, (LPCSTR)from, (int)fromlen,
								     NULL, 0);
		if (needed == 0)
		{
		    // When conversion fails there may be a trailing byte.
		    needed = MultiByteToWideChar(enc_codepage,
			 MB_ERR_INVALID_CHARS, (LPCSTR)from, (int)fromlen - 1,
								     NULL, 0);
		    if (needed == 0)
		    {
			// Conversion doesn't work.
			ip->bw_conv_error = TRUE;
			return FAIL;
		    }
		    // Save the trailing byte for the next call.
		    ip->bw_rest[0] = from[fromlen - 1];
		    ip->bw_restlen = 1;
		}
		needed = MultiByteToWideChar(enc_codepage, MB_ERR_INVALID_CHARS,
				(LPCSTR)from, (int)(fromlen - ip->bw_restlen),
							  (LPWSTR)to, needed);
		if (needed == 0)
		{
		    // Safety check: Conversion doesn't work.
		    ip->bw_conv_error = TRUE;
		    return FAIL;
		}
		to += needed * 2;
	    }

	    fromlen = to - ip->bw_conv_buf;
	    buf = to;
# ifdef CP_UTF8	// VC 4.1 doesn't define CP_UTF8
	    if (FIO_GET_CP(flags) == CP_UTF8)
	    {
		// Convert from UCS-2 to UTF-8, using the remainder of the
		// conversion buffer.  Fails when out of space.
		for (from = ip->bw_conv_buf; fromlen > 1; fromlen -= 2)
		{
		    u8c = *from++;
		    u8c += (*from++ << 8);
		    to += utf_char2bytes(u8c, to);
		    if (to + 6 >= ip->bw_conv_buf + ip->bw_conv_buflen)
		    {
			ip->bw_conv_error = TRUE;
			return FAIL;
		    }
		}
		len = (int)(to - buf);
	    }
	    else
# endif
	    {
		// Convert from UCS-2 to the codepage, using the remainder of
		// the conversion buffer.  If the conversion uses the default
		// character "0", the data doesn't fit in this encoding, so
		// fail.
		len = WideCharToMultiByte(FIO_GET_CP(flags), 0,
			(LPCWSTR)ip->bw_conv_buf, (int)fromlen / sizeof(WCHAR),
			(LPSTR)to, (int)(ip->bw_conv_buflen - fromlen), 0,
									&bad);
		if (bad)
		{
		    ip->bw_conv_error = TRUE;
		    return FAIL;
		}
	    }
	}
#endif

#ifdef MACOS_CONVERT
	else if (flags & FIO_MACROMAN)
	{
	    // Convert UTF-8 or latin1 to Apple MacRoman.
	    char_u	*from;
	    size_t	fromlen;

	    if (ip->bw_restlen > 0)
	    {
		// Need to concatenate the remainder of the previous call and
		// the bytes of the current call.  Use the end of the
		// conversion buffer for this.
		fromlen = len + ip->bw_restlen;
		from = ip->bw_conv_buf + ip->bw_conv_buflen - fromlen;
		mch_memmove(from, ip->bw_rest, (size_t)ip->bw_restlen);
		mch_memmove(from + ip->bw_restlen, buf, (size_t)len);
	    }
	    else
	    {
		from = buf;
		fromlen = len;
	    }

	    if (enc2macroman(from, fromlen,
			ip->bw_conv_buf, &len, ip->bw_conv_buflen,
			ip->bw_rest, &ip->bw_restlen) == FAIL)
	    {
		ip->bw_conv_error = TRUE;
		return FAIL;
	    }
	    buf = ip->bw_conv_buf;
	}
#endif

#ifdef USE_ICONV
	if (ip->bw_iconv_fd != (iconv_t)-1)
	{
	    const char	*from;
	    size_t	fromlen;
	    char	*to;
	    size_t	tolen;

	    // Convert with iconv().
	    if (ip->bw_restlen > 0)
	    {
		char *fp;

		// Need to concatenate the remainder of the previous call and
		// the bytes of the current call.  Use the end of the
		// conversion buffer for this.
		fromlen = len + ip->bw_restlen;
		fp = (char *)ip->bw_conv_buf + ip->bw_conv_buflen - fromlen;
		mch_memmove(fp, ip->bw_rest, (size_t)ip->bw_restlen);
		mch_memmove(fp + ip->bw_restlen, buf, (size_t)len);
		from = fp;
		tolen = ip->bw_conv_buflen - fromlen;
	    }
	    else
	    {
		from = (const char *)buf;
		fromlen = len;
		tolen = ip->bw_conv_buflen;
	    }
	    to = (char *)ip->bw_conv_buf;

	    if (ip->bw_first)
	    {
		size_t	save_len = tolen;

		// output the initial shift state sequence
		(void)iconv(ip->bw_iconv_fd, NULL, NULL, &to, &tolen);

		// There is a bug in iconv() on Linux (which appears to be
		// wide-spread) which sets "to" to NULL and messes up "tolen".
		if (to == NULL)
		{
		    to = (char *)ip->bw_conv_buf;
		    tolen = save_len;
		}
		ip->bw_first = FALSE;
	    }

	    // If iconv() has an error or there is not enough room, fail.
	    if ((iconv(ip->bw_iconv_fd, (void *)&from, &fromlen, &to, &tolen)
			== (size_t)-1 && ICONV_ERRNO != ICONV_EINVAL)
						    || fromlen > CONV_RESTLEN)
	    {
		ip->bw_conv_error = TRUE;
		return FAIL;
	    }

	    // copy remainder to ip->bw_rest[] to be used for the next call.
	    if (fromlen > 0)
		mch_memmove(ip->bw_rest, (void *)from, fromlen);
	    ip->bw_restlen = (int)fromlen;

	    buf = ip->bw_conv_buf;
	    len = (int)((char_u *)to - ip->bw_conv_buf);
	}
#endif
    }

    if (ip->bw_fd < 0)
	// Only checking conversion, which is OK if we get here.
	return OK;

#ifdef FEAT_CRYPT
    if (flags & FIO_ENCRYPTED)
    {
	// Encrypt the data. Do it in-place if possible, otherwise use an
	// allocated buffer.
# ifdef CRYPT_NOT_INPLACE
	if (crypt_works_inplace(ip->bw_buffer->b_cryptstate))
	{
# endif
	    crypt_encode_inplace(ip->bw_buffer->b_cryptstate, buf, len,
								ip->bw_finish);
# ifdef CRYPT_NOT_INPLACE
	}
	else
	{
	    char_u *outbuf;

	    len = crypt_encode_alloc(curbuf->b_cryptstate, buf, len, &outbuf,
								ip->bw_finish);
	    if (len == 0)
		return OK;  // Crypt layer is buffering, will flush later.
	    wlen = write_eintr(ip->bw_fd, outbuf, len);
	    vim_free(outbuf);
	    return (wlen < len) ? FAIL : OK;
	}
# endif
    }
#endif

    wlen = write_eintr(ip->bw_fd, buf, len);
    return (wlen < len) ? FAIL : OK;
}

/*
 * Check modification time of file, before writing to it.
 * The size isn't checked, because using a tool like "gzip" takes care of
 * using the same timestamp but can't set the size.
 */
    static int
check_mtime(buf_T *buf, stat_T *st)
{
    if (buf->b_mtime_read != 0
		  && time_differs(st, buf->b_mtime_read, buf->b_mtime_read_ns))
    {
	msg_scroll = TRUE;	    // don't overwrite messages here
	msg_silent = 0;		    // must give this prompt
	// don't use emsg() here, don't want to flush the buffers
	msg_attr(_("WARNING: The file has been changed since reading it!!!"),
						       HL_ATTR(HLF_E));
	if (ask_yesno((char_u *)_("Do you really want to write to it"),
								 TRUE) == 'n')
	    return FAIL;
	msg_scroll = FALSE;	    // always overwrite the file message now
    }
    return OK;
}

/*
 * Generate a BOM in "buf[4]" for encoding "name".
 * Return the length of the BOM (zero when no BOM).
 */
    static int
make_bom(char_u *buf, char_u *name)
{
    int		flags;
    char_u	*p;

    flags = get_fio_flags(name);

    // Can't put a BOM in a non-Unicode file.
    if (flags == FIO_LATIN1 || flags == 0)
	return 0;

    if (flags == FIO_UTF8)	// UTF-8
    {
	buf[0] = 0xef;
	buf[1] = 0xbb;
	buf[2] = 0xbf;
	return 3;
    }
    p = buf;
    (void)ucs2bytes(0xfeff, &p, flags);
    return (int)(p - buf);
}

#ifdef UNIX
    static void
set_file_time(
    char_u  *fname,
    time_t  atime,	    // access time
    time_t  mtime)	    // modification time
{
# if defined(HAVE_UTIME) && defined(HAVE_UTIME_H)
    struct utimbuf  buf;

    buf.actime	= atime;
    buf.modtime	= mtime;
    (void)utime((char *)fname, &buf);
# else
#  if defined(HAVE_UTIMES)
    struct timeval  tvp[2];

    tvp[0].tv_sec   = atime;
    tvp[0].tv_usec  = 0;
    tvp[1].tv_sec   = mtime;
    tvp[1].tv_usec  = 0;
#   ifdef NeXT
    (void)utimes((char *)fname, tvp);
#   else
    (void)utimes((char *)fname, (const struct timeval *)&tvp);
#   endif
#  endif
# endif
}
#endif // UNIX

    char *
new_file_message(void)
{
    return shortmess(SHM_NEW) ? _("[New]") : _("[New File]");
}

/*
 * buf_write() - write to file "fname" lines "start" through "end"
 *
 * We do our own buffering here because fwrite() is so slow.
 *
 * If "forceit" is true, we don't care for errors when attempting backups.
 * In case of an error everything possible is done to restore the original
 * file.  But when "forceit" is TRUE, we risk losing it.
 *
 * When "reset_changed" is TRUE and "append" == FALSE and "start" == 1 and
 * "end" == curbuf->b_ml.ml_line_count, reset curbuf->b_changed.
 *
 * This function must NOT use NameBuff (because it's called by autowrite()).
 *
 * return FAIL for failure, OK otherwise
 */
    int
buf_write(
    buf_T	    *buf,
    char_u	    *fname,
    char_u	    *sfname,
    linenr_T	    start,
    linenr_T	    end,
    exarg_T	    *eap,		// for forced 'ff' and 'fenc', can be
					// NULL!
    int		    append,		// append to the file
    int		    forceit,
    int		    reset_changed,
    int		    filtering)
{
    int		    fd;
    char_u	    *backup = NULL;
    int		    backup_copy = FALSE; // copy the original file?
    int		    dobackup;
    char_u	    *ffname;
    char_u	    *wfname = NULL;	// name of file to write to
    char_u	    *s;
    char_u	    *ptr;
    char_u	    c;
    int		    len;
    linenr_T	    lnum;
    long	    nchars;
    char_u	    *errmsg = NULL;
    int		    errmsg_allocated = FALSE;
    char_u	    *errnum = NULL;
    char_u	    *buffer;
    char_u	    smallbuf[SMALLBUFSIZE];
    char_u	    *backup_ext;
    int		    bufsize;
    long	    perm;		    // file permissions
    int		    retval = OK;
    int		    newfile = FALSE;	    // TRUE if file doesn't exist yet
    int		    msg_save = msg_scroll;
    int		    overwriting;	    // TRUE if writing over original
    int		    no_eol = FALSE;	    // no end-of-line written
    int		    device = FALSE;	    // writing to a device
    stat_T	    st_old;
    int		    prev_got_int = got_int;
    int		    checking_conversion;
    int		    file_readonly = FALSE;  // overwritten file is read-only
#if defined(UNIX)			    // XXX fix me sometime?
    int		    made_writable = FALSE;  // 'w' bit has been set
#endif
					// writing everything
    int		    whole = (start == 1 && end == buf->b_ml.ml_line_count);
    linenr_T	    old_line_count = buf->b_ml.ml_line_count;
    int		    attr;
    int		    fileformat;
    int		    write_bin;
    struct bw_info  write_info;		// info for buf_write_bytes()
    int		    converted = FALSE;
    int		    notconverted = FALSE;
    char_u	    *fenc;		// effective 'fileencoding'
    char_u	    *fenc_tofree = NULL; // allocated "fenc"
    int		    wb_flags = 0;
#ifdef HAVE_ACL
    vim_acl_T	    acl = NULL;		// ACL copied from original file to
					// backup or new file
#endif
#ifdef FEAT_PERSISTENT_UNDO
    int		    write_undo_file = FALSE;
    context_sha256_T sha_ctx;
#endif
    unsigned int    bkc = get_bkc_value(buf);
    pos_T	    orig_start = buf->b_op_start;
    pos_T	    orig_end = buf->b_op_end;

    if (fname == NULL || *fname == NUL)	// safety check
	return FAIL;
    if (buf->b_ml.ml_mfp == NULL)
    {
	// This can happen during startup when there is a stray "w" in the
	// vimrc file.
	emsg(_(e_empty_buffer));
	return FAIL;
    }

    // Disallow writing from .exrc and .vimrc in current directory for
    // security reasons.
    if (check_secure())
	return FAIL;

    // Avoid a crash for a long name.
    if (STRLEN(fname) >= MAXPATHL)
    {
	emsg(_(e_name_too_long));
	return FAIL;
    }

    // must init bw_conv_buf and bw_iconv_fd before jumping to "fail"
    write_info.bw_conv_buf = NULL;
    write_info.bw_conv_error = FALSE;
    write_info.bw_conv_error_lnum = 0;
    write_info.bw_restlen = 0;
#ifdef USE_ICONV
    write_info.bw_iconv_fd = (iconv_t)-1;
#endif
#ifdef FEAT_CRYPT
    write_info.bw_buffer = buf;
    write_info.bw_finish = FALSE;
#endif

    // After writing a file changedtick changes but we don't want to display
    // the line.
    ex_no_reprint = TRUE;

    // If there is no file name yet, use the one for the written file.
    // BF_NOTEDITED is set to reflect this (in case the write fails).
    // Don't do this when the write is for a filter command.
    // Don't do this when appending.
    // Only do this when 'cpoptions' contains the 'F' flag.
    if (buf->b_ffname == NULL
	    && reset_changed
	    && whole
	    && buf == curbuf
	    && !bt_nofilename(buf)
	    && !filtering
	    && (!append || vim_strchr(p_cpo, CPO_FNAMEAPP) != NULL)
	    && vim_strchr(p_cpo, CPO_FNAMEW) != NULL)
    {
	if (set_rw_fname(fname, sfname) == FAIL)
	    return FAIL;
	buf = curbuf;	    // just in case autocmds made "buf" invalid
    }

    if (sfname == NULL)
	sfname = fname;
    // For Unix: Use the short file name whenever possible.
    // Avoids problems with networks and when directory names are changed.
    // Don't do this for MS-DOS, a "cd" in a sub-shell may have moved us to
    // another directory, which we don't detect
    ffname = fname;			    // remember full fname
#ifdef UNIX
    fname = sfname;
#endif

    if (buf->b_ffname != NULL && fnamecmp(ffname, buf->b_ffname) == 0)
	overwriting = TRUE;
    else
	overwriting = FALSE;

    if (exiting)
	settmode(TMODE_COOK);	    // when exiting allow typeahead now

    ++no_wait_return;		    // don't wait for return yet

    // Set '[ and '] marks to the lines to be written.
    buf->b_op_start.lnum = start;
    buf->b_op_start.col = 0;
    buf->b_op_end.lnum = end;
    buf->b_op_end.col = 0;

    {
	aco_save_T	aco;
	int		buf_ffname = FALSE;
	int		buf_sfname = FALSE;
	int		buf_fname_f = FALSE;
	int		buf_fname_s = FALSE;
	int		did_cmd = FALSE;
	int		nofile_err = FALSE;
	int		empty_memline = (buf->b_ml.ml_mfp == NULL);
	bufref_T	bufref;

	// Apply PRE autocommands.
	// Set curbuf to the buffer to be written.
	// Careful: The autocommands may call buf_write() recursively!
	if (ffname == buf->b_ffname)
	    buf_ffname = TRUE;
	if (sfname == buf->b_sfname)
	    buf_sfname = TRUE;
	if (fname == buf->b_ffname)
	    buf_fname_f = TRUE;
	if (fname == buf->b_sfname)
	    buf_fname_s = TRUE;

	// Set curwin/curbuf to buf and save a few things.
	aucmd_prepbuf(&aco, buf);
	if (curbuf != buf)
	{
	    // Could not find a window for "buf".  Doing more might cause
	    // problems, better bail out.
	    return FAIL;
	}

	set_bufref(&bufref, buf);

	if (append)
	{
	    if (!(did_cmd = apply_autocmds_exarg(EVENT_FILEAPPENDCMD,
					 sfname, sfname, FALSE, curbuf, eap)))
	    {
		if (overwriting && bt_nofilename(curbuf))
		    nofile_err = TRUE;
		else
		    apply_autocmds_exarg(EVENT_FILEAPPENDPRE,
					  sfname, sfname, FALSE, curbuf, eap);
	    }
	}
	else if (filtering)
	{
	    apply_autocmds_exarg(EVENT_FILTERWRITEPRE,
					    NULL, sfname, FALSE, curbuf, eap);
	}
	else if (reset_changed && whole)
	{
	    int was_changed = curbufIsChanged();

	    did_cmd = apply_autocmds_exarg(EVENT_BUFWRITECMD,
					  sfname, sfname, FALSE, curbuf, eap);
	    if (did_cmd)
	    {
		if (was_changed && !curbufIsChanged())
		{
		    // Written everything correctly and BufWriteCmd has reset
		    // 'modified': Correct the undo information so that an
		    // undo now sets 'modified'.
		    u_unchanged(curbuf);
		    u_update_save_nr(curbuf);
		}
	    }
	    else
	    {
		if (overwriting && bt_nofilename(curbuf))
		    nofile_err = TRUE;
		else
		    apply_autocmds_exarg(EVENT_BUFWRITEPRE,
					  sfname, sfname, FALSE, curbuf, eap);
	    }
	}
	else
	{
	    if (!(did_cmd = apply_autocmds_exarg(EVENT_FILEWRITECMD,
					 sfname, sfname, FALSE, curbuf, eap)))
	    {
		if (overwriting && bt_nofilename(curbuf))
		    nofile_err = TRUE;
		else
		    apply_autocmds_exarg(EVENT_FILEWRITEPRE,
					  sfname, sfname, FALSE, curbuf, eap);
	    }
	}

	// restore curwin/curbuf and a few other things
	aucmd_restbuf(&aco);

	// In three situations we return here and don't write the file:
	// 1. the autocommands deleted or unloaded the buffer.
	// 2. The autocommands abort script processing.
	// 3. If one of the "Cmd" autocommands was executed.
	if (!bufref_valid(&bufref))
	    buf = NULL;
	if (buf == NULL || (buf->b_ml.ml_mfp == NULL && !empty_memline)
				       || did_cmd || nofile_err
#ifdef FEAT_EVAL
				       || aborting()
#endif
				       )
	{
	    if (buf != NULL && (cmdmod.cmod_flags & CMOD_LOCKMARKS))
	    {
		// restore the original '[ and '] positions
		buf->b_op_start = orig_start;
		buf->b_op_end = orig_end;
	    }

	    --no_wait_return;
	    msg_scroll = msg_save;
	    if (nofile_err)
		semsg(_(e_no_matching_autocommands_for_buftype_str_buffer),
							       curbuf->b_p_bt);

	    if (nofile_err
#ifdef FEAT_EVAL
		    || aborting()
#endif
		    )
		// An aborting error, interrupt or exception in the
		// autocommands.
		return FAIL;
	    if (did_cmd)
	    {
		if (buf == NULL)
		    // The buffer was deleted.  We assume it was written
		    // (can't retry anyway).
		    return OK;
		if (overwriting)
		{
		    // Assume the buffer was written, update the timestamp.
		    ml_timestamp(buf);
		    if (append)
			buf->b_flags &= ~BF_NEW;
		    else
			buf->b_flags &= ~BF_WRITE_MASK;
		}
		if (reset_changed && buf->b_changed && !append
			&& (overwriting || vim_strchr(p_cpo, CPO_PLUS) != NULL))
		    // Buffer still changed, the autocommands didn't work
		    // properly.
		    return FAIL;
		return OK;
	    }
#ifdef FEAT_EVAL
	    if (!aborting())
#endif
		emsg(_(e_autocommands_deleted_or_unloaded_buffer_to_be_written));
	    return FAIL;
	}

	// The autocommands may have changed the number of lines in the file.
	// When writing the whole file, adjust the end.
	// When writing part of the file, assume that the autocommands only
	// changed the number of lines that are to be written (tricky!).
	if (buf->b_ml.ml_line_count != old_line_count)
	{
	    if (whole)						// write all
		end = buf->b_ml.ml_line_count;
	    else if (buf->b_ml.ml_line_count > old_line_count)	// more lines
		end += buf->b_ml.ml_line_count - old_line_count;
	    else						// less lines
	    {
		end -= old_line_count - buf->b_ml.ml_line_count;
		if (end < start)
		{
		    --no_wait_return;
		    msg_scroll = msg_save;
		    emsg(_(e_autocommands_changed_number_of_lines_in_unexpected_way));
		    return FAIL;
		}
	    }
	}

	// The autocommands may have changed the name of the buffer, which may
	// be kept in fname, ffname and sfname.
	if (buf_ffname)
	    ffname = buf->b_ffname;
	if (buf_sfname)
	    sfname = buf->b_sfname;
	if (buf_fname_f)
	    fname = buf->b_ffname;
	if (buf_fname_s)
	    fname = buf->b_sfname;
    }

    if (cmdmod.cmod_flags & CMOD_LOCKMARKS)
    {
	// restore the original '[ and '] positions
	buf->b_op_start = orig_start;
	buf->b_op_end = orig_end;
    }

#ifdef FEAT_NETBEANS_INTG
    if (netbeans_active() && isNetbeansBuffer(buf))
    {
	if (whole)
	{
	    // b_changed can be 0 after an undo, but we still need to write
	    // the buffer to NetBeans.
	    if (buf->b_changed || isNetbeansModified(buf))
	    {
		--no_wait_return;		// may wait for return now
		msg_scroll = msg_save;
		netbeans_save_buffer(buf);	// no error checking...
		return retval;
	    }
	    else
	    {
		errnum = (char_u *)"E656: ";
		errmsg = (char_u *)_(e_netbeans_disallows_writes_of_unmodified_buffers);
		buffer = NULL;
		goto fail;
	    }
	}
	else
	{
	    errnum = (char_u *)"E657: ";
	    errmsg = (char_u *)_(e_partial_writes_disallowed_for_netbeans_buffers);
	    buffer = NULL;
	    goto fail;
	}
    }
#endif

    if (shortmess(SHM_OVER) && !exiting)
	msg_scroll = FALSE;	    // overwrite previous file message
    else
	msg_scroll = TRUE;	    // don't overwrite previous file message
    if (!filtering)
	filemess(buf,
#ifndef UNIX
		sfname,
#else
		fname,
#endif
		    (char_u *)"", 0);	// show that we are busy
    msg_scroll = FALSE;		    // always overwrite the file message now

    buffer = alloc(WRITEBUFSIZE);
    if (buffer == NULL)		    // can't allocate big buffer, use small
				    // one (to be able to write when out of
				    // memory)
    {
	buffer = smallbuf;
	bufsize = SMALLBUFSIZE;
    }
    else
	bufsize = WRITEBUFSIZE;

    // Get information about original file (if there is one).
#if defined(UNIX)
    st_old.st_dev = 0;
    st_old.st_ino = 0;
    perm = -1;
    if (mch_stat((char *)fname, &st_old) < 0)
	newfile = TRUE;
    else
    {
	perm = st_old.st_mode;
	if (!S_ISREG(st_old.st_mode))		// not a file
	{
	    if (S_ISDIR(st_old.st_mode))
	    {
		errnum = (char_u *)"E502: ";
		errmsg = (char_u *)_(e_is_a_directory);
		goto fail;
	    }
	    if (mch_nodetype(fname) != NODE_WRITABLE)
	    {
		errnum = (char_u *)"E503: ";
		errmsg = (char_u *)_(e_is_not_file_or_writable_device);
		goto fail;
	    }
	    // It's a device of some kind (or a fifo) which we can write to
	    // but for which we can't make a backup.
	    device = TRUE;
	    newfile = TRUE;
	    perm = -1;
	}
    }
#else // !UNIX
    // Check for a writable device name.
    c = mch_nodetype(fname);
    if (c == NODE_OTHER)
    {
	errnum = (char_u *)"E503: ";
	errmsg = (char_u *)_(e_is_not_file_or_writable_device);
	goto fail;
    }
    if (c == NODE_WRITABLE)
    {
# if defined(MSWIN)
	// MS-Windows allows opening a device, but we will probably get stuck
	// trying to write to it.
	if (!p_odev)
	{
	    errnum = (char_u *)"E796: ";
	    errmsg = (char_u *)_(e_writing_to_device_disabled_with_opendevice_option);
	    goto fail;
	}
# endif
	device = TRUE;
	newfile = TRUE;
	perm = -1;
    }
    else
    {
	perm = mch_getperm(fname);
	if (perm < 0)
	    newfile = TRUE;
	else if (mch_isdir(fname))
	{
	    errnum = (char_u *)"E502: ";
	    errmsg = (char_u *)_(e_is_a_directory);
	    goto fail;
	}
	if (overwriting)
	    (void)mch_stat((char *)fname, &st_old);
    }
#endif // !UNIX

    if (!device && !newfile)
    {
	// Check if the file is really writable (when renaming the file to
	// make a backup we won't discover it later).
	file_readonly = check_file_readonly(fname, (int)perm);

	if (!forceit && file_readonly)
	{
	    if (vim_strchr(p_cpo, CPO_FWRITE) != NULL)
	    {
		errnum = (char_u *)"E504: ";
		errmsg = (char_u *)_(e_is_read_only_cannot_override_W_in_cpoptions);
	    }
	    else
	    {
		errnum = (char_u *)"E505: ";
		errmsg = (char_u *)_(e_is_read_only_add_bang_to_override);
	    }
	    goto fail;
	}

	// Check if the timestamp hasn't changed since reading the file.
	if (overwriting)
	{
	    retval = check_mtime(buf, &st_old);
	    if (retval == FAIL)
		goto fail;
	}
    }

#ifdef HAVE_ACL
    // For systems that support ACL: get the ACL from the original file.
    if (!newfile)
	acl = mch_get_acl(fname);
#endif

    // If 'backupskip' is not empty, don't make a backup for some files.
    dobackup = (p_wb || p_bk || *p_pm != NUL);
    if (dobackup && *p_bsk != NUL && match_file_list(p_bsk, sfname, ffname))
	dobackup = FALSE;

    // Save the value of got_int and reset it.  We don't want a previous
    // interruption cancel writing, only hitting CTRL-C while writing should
    // abort it.
    prev_got_int = got_int;
    got_int = FALSE;

    // Mark the buffer as 'being saved' to prevent changed buffer warnings
    buf->b_saving = TRUE;

    // If we are not appending or filtering, the file exists, and the
    // 'writebackup', 'backup' or 'patchmode' option is set, need a backup.
    // When 'patchmode' is set also make a backup when appending.
    //
    // Do not make any backup, if 'writebackup' and 'backup' are both switched
    // off.  This helps when editing large files on almost-full disks.
    if (!(append && *p_pm == NUL) && !filtering && perm >= 0 && dobackup)
    {
#if defined(UNIX) || defined(MSWIN)
	stat_T	    st;
#endif

	if ((bkc & BKC_YES) || append)	// "yes"
	    backup_copy = TRUE;
#if defined(UNIX) || defined(MSWIN)
	else if ((bkc & BKC_AUTO))	// "auto"
	{
	    int		i;

# ifdef UNIX
	    // Don't rename the file when:
	    // - it's a hard link
	    // - it's a symbolic link
	    // - we don't have write permission in the directory
	    // - we can't set the owner/group of the new file
	    if (st_old.st_nlink > 1
		    || mch_lstat((char *)fname, &st) < 0
		    || st.st_dev != st_old.st_dev
		    || st.st_ino != st_old.st_ino
#  ifndef HAVE_FCHOWN
		    || st.st_uid != st_old.st_uid
		    || st.st_gid != st_old.st_gid
#  endif
		    )
		backup_copy = TRUE;
	    else
# else
#  ifdef MSWIN
	    // On NTFS file systems hard links are possible.
	    if (mch_is_linked(fname))
		backup_copy = TRUE;
	    else
#  endif
# endif
	    {
		// Check if we can create a file and set the owner/group to
		// the ones from the original file.
		// First find a file name that doesn't exist yet (use some
		// arbitrary numbers).
		STRCPY(IObuff, fname);
		fd = -1;
		for (i = 4913; ; i += 123)
		{
		    sprintf((char *)gettail(IObuff), "%d", i);
		    if (mch_lstat((char *)IObuff, &st) < 0)
		    {
			fd = mch_open((char *)IObuff,
				    O_CREAT|O_WRONLY|O_EXCL|O_NOFOLLOW, perm);
			if (fd < 0 && errno == EEXIST)
			    // If the same file name is created by another
			    // process between lstat() and open(), find another
			    // name.
			    continue;
			break;
		    }
		}
		if (fd < 0)	// can't write in directory
		    backup_copy = TRUE;
		else
		{
# ifdef UNIX
#  ifdef HAVE_FCHOWN
		    vim_ignored = fchown(fd, st_old.st_uid, st_old.st_gid);
#  endif
		    if (mch_stat((char *)IObuff, &st) < 0
			    || st.st_uid != st_old.st_uid
			    || st.st_gid != st_old.st_gid
			    || (long)st.st_mode != perm)
			backup_copy = TRUE;
# endif
		    // Close the file before removing it, on MS-Windows we
		    // can't delete an open file.
		    close(fd);
		    mch_remove(IObuff);
# ifdef MSWIN
		    // MS-Windows may trigger a virus scanner to open the
		    // file, we can't delete it then.  Keep trying for half a
		    // second.
		    {
			int try;

			for (try = 0; try < 10; ++try)
			{
			    if (mch_lstat((char *)IObuff, &st) < 0)
				break;
			    ui_delay(50L, TRUE);  // wait 50 msec
			    mch_remove(IObuff);
			}
		    }
# endif
		}
	    }
	}

	// Break symlinks and/or hardlinks if we've been asked to.
	if ((bkc & BKC_BREAKSYMLINK) || (bkc & BKC_BREAKHARDLINK))
	{
# ifdef UNIX
	    int	lstat_res;

	    lstat_res = mch_lstat((char *)fname, &st);

	    // Symlinks.
	    if ((bkc & BKC_BREAKSYMLINK)
		    && lstat_res == 0
		    && st.st_ino != st_old.st_ino)
		backup_copy = FALSE;

	    // Hardlinks.
	    if ((bkc & BKC_BREAKHARDLINK)
		    && st_old.st_nlink > 1
		    && (lstat_res != 0 || st.st_ino == st_old.st_ino))
		backup_copy = FALSE;
# else
#  if defined(MSWIN)
	    // Symlinks.
	    if ((bkc & BKC_BREAKSYMLINK) && mch_is_symbolic_link(fname))
		backup_copy = FALSE;

	    // Hardlinks.
	    if ((bkc & BKC_BREAKHARDLINK) && mch_is_hard_link(fname))
		backup_copy = FALSE;
#  endif
# endif
	}

#endif

	// make sure we have a valid backup extension to use
	if (*p_bex == NUL)
	    backup_ext = (char_u *)".bak";
	else
	    backup_ext = p_bex;

	if (backup_copy
		&& (fd = mch_open((char *)fname, O_RDONLY | O_EXTRA, 0)) >= 0)
	{
	    int		bfd;
	    char_u	*copybuf, *wp;
	    int		some_error = FALSE;
	    stat_T	st_new;
	    char_u	*dirp;
	    char_u	*rootname;
#if defined(UNIX) || defined(MSWIN)
	    char_u      *p;
#endif
#if defined(UNIX)
	    int		did_set_shortname;
	    mode_t	umask_save;
#endif

	    copybuf = alloc(WRITEBUFSIZE + 1);
	    if (copybuf == NULL)
	    {
		some_error = TRUE;	    // out of memory
		goto nobackup;
	    }

	    // Try to make the backup in each directory in the 'bdir' option.
	    //
	    // Unix semantics has it, that we may have a writable file,
	    // that cannot be recreated with a simple open(..., O_CREAT, ) e.g:
	    //  - the directory is not writable,
	    //  - the file may be a symbolic link,
	    //  - the file may belong to another user/group, etc.
	    //
	    // For these reasons, the existing writable file must be truncated
	    // and reused. Creation of a backup COPY will be attempted.
	    dirp = p_bdir;
	    while (*dirp)
	    {
#ifdef UNIX
		st_new.st_ino = 0;
		st_new.st_dev = 0;
		st_new.st_gid = 0;
#endif

		// Isolate one directory name, using an entry in 'bdir'.
		(void)copy_option_part(&dirp, copybuf, WRITEBUFSIZE, ",");

#if defined(UNIX) || defined(MSWIN)
		p = copybuf + STRLEN(copybuf);
		if (after_pathsep(copybuf, p) && p[-1] == p[-2])
		    // Ends with '//', use full path
		    if ((p = make_percent_swname(copybuf, fname)) != NULL)
		    {
			backup = modname(p, backup_ext, FALSE);
			vim_free(p);
		    }
#endif
		rootname = get_file_in_dir(fname, copybuf);
		if (rootname == NULL)
		{
		    some_error = TRUE;	    // out of memory
		    goto nobackup;
		}

#if defined(UNIX)
		did_set_shortname = FALSE;
#endif

		// May try twice if 'shortname' not set.
		for (;;)
		{
		    // Make the backup file name.
		    if (backup == NULL)
			backup = buf_modname((buf->b_p_sn || buf->b_shortname),
						 rootname, backup_ext, FALSE);
		    if (backup == NULL)
		    {
			vim_free(rootname);
			some_error = TRUE;		// out of memory
			goto nobackup;
		    }

		    // Check if backup file already exists.
		    if (mch_stat((char *)backup, &st_new) >= 0)
		    {
#ifdef UNIX
			// Check if backup file is same as original file.
			// May happen when modname() gave the same file back.
			// E.g. silly link, or file name-length reached.
			// If we don't check here, we either ruin the file
			// when copying or erase it after writing. jw.
			if (st_new.st_dev == st_old.st_dev
					    && st_new.st_ino == st_old.st_ino)
			{
			    VIM_CLEAR(backup);	// no backup file to delete
			    // may try again with 'shortname' set
			    if (!(buf->b_shortname || buf->b_p_sn))
			    {
				buf->b_shortname = TRUE;
				did_set_shortname = TRUE;
				continue;
			    }
				// setting shortname didn't help
			    if (did_set_shortname)
				buf->b_shortname = FALSE;
			    break;
			}
#endif

			// If we are not going to keep the backup file, don't
			// delete an existing one, try to use another name.
			// Change one character, just before the extension.
			if (!p_bk)
			{
			    wp = backup + STRLEN(backup) - 1
							 - STRLEN(backup_ext);
			    if (wp < backup)	// empty file name ???
				wp = backup;
			    *wp = 'z';
			    while (*wp > 'a'
				    && mch_stat((char *)backup, &st_new) >= 0)
				--*wp;
			    // They all exist??? Must be something wrong.
			    if (*wp == 'a')
				VIM_CLEAR(backup);
			}
		    }
		    break;
		}
		vim_free(rootname);

		// Try to create the backup file
		if (backup != NULL)
		{
		    // remove old backup, if present
		    mch_remove(backup);
		    // Open with O_EXCL to avoid the file being created while
		    // we were sleeping (symlink hacker attack?). Reset umask
		    // if possible to avoid mch_setperm() below.
#ifdef UNIX
		    umask_save = umask(0);
#endif
		    bfd = mch_open((char *)backup,
				O_WRONLY|O_CREAT|O_EXTRA|O_EXCL|O_NOFOLLOW,
								 perm & 0777);
#ifdef UNIX
		    (void)umask(umask_save);
#endif
		    if (bfd < 0)
			VIM_CLEAR(backup);
		    else
		    {
			// Set file protection same as original file, but
			// strip s-bit.  Only needed if umask() wasn't used
			// above.
#ifndef UNIX
			(void)mch_setperm(backup, perm & 0777);
#else
			// Try to set the group of the backup same as the
			// original file. If this fails, set the protection
			// bits for the group same as the protection bits for
			// others.
			if (st_new.st_gid != st_old.st_gid
# ifdef HAVE_FCHOWN  // sequent-ptx lacks fchown()
				&& fchown(bfd, (uid_t)-1, st_old.st_gid) != 0
# endif
						)
			    mch_setperm(backup,
					  (perm & 0707) | ((perm & 07) << 3));
# if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
			mch_copy_sec(fname, backup);
# endif
# ifdef FEAT_XATTR
			mch_copy_xattr(fname, backup);
# endif
#endif

			// copy the file.
			write_info.bw_fd = bfd;
			write_info.bw_buf = copybuf;
			write_info.bw_flags = FIO_NOCONVERT;
			while ((write_info.bw_len = read_eintr(fd, copybuf,
							    WRITEBUFSIZE)) > 0)
			{
			    if (buf_write_bytes(&write_info) == FAIL)
			    {
				errmsg = (char_u *)_(e_cant_write_to_backup_file_add_bang_to_override);
				break;
			    }
			    ui_breakcheck();
			    if (got_int)
			    {
				errmsg = (char_u *)_(e_interrupted);
				break;
			    }
			}

			if (close(bfd) < 0 && errmsg == NULL)
			    errmsg = (char_u *)_(e_close_error_for_backup_file_add_bang_to_write_anyway);
			if (write_info.bw_len < 0)
			    errmsg = (char_u *)_(e_cant_read_file_for_backup_add_bang_to_write_anyway);
#ifdef UNIX
			set_file_time(backup, st_old.st_atime, st_old.st_mtime);
#endif
#ifdef HAVE_ACL
			mch_set_acl(backup, acl);
#endif
#if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
			mch_copy_sec(fname, backup);
#endif
#ifdef FEAT_XATTR
			mch_copy_xattr(fname, backup);
#endif
#ifdef MSWIN
			(void)mch_copy_file_attribute(fname, backup);
#endif
			break;
		    }
		}
	    }
    nobackup:
	    close(fd);		// ignore errors for closing read file
	    vim_free(copybuf);

	    if (backup == NULL && errmsg == NULL)
		errmsg = (char_u *)_(e_cannot_create_backup_file_add_bang_to_write_anyway);
	    // ignore errors when forceit is TRUE
	    if ((some_error || errmsg != NULL) && !forceit)
	    {
		retval = FAIL;
		goto fail;
	    }
	    errmsg = NULL;
	}
	else
	{
	    char_u	*dirp;
	    char_u	*p;
	    char_u	*rootname;

	    // Make a backup by renaming the original file.

	    // If 'cpoptions' includes the "W" flag, we don't want to
	    // overwrite a read-only file.  But rename may be possible
	    // anyway, thus we need an extra check here.
	    if (file_readonly && vim_strchr(p_cpo, CPO_FWRITE) != NULL)
	    {
		errnum = (char_u *)"E504: ";
		errmsg = (char_u *)_(e_is_read_only_cannot_override_W_in_cpoptions);
		goto fail;
	    }

	    // Form the backup file name - change path/fo.o.h to
	    // path/fo.o.h.bak Try all directories in 'backupdir', first one
	    // that works is used.
	    dirp = p_bdir;
	    while (*dirp)
	    {
		// Isolate one directory name and make the backup file name.
		(void)copy_option_part(&dirp, IObuff, IOSIZE, ",");

#if defined(UNIX) || defined(MSWIN)
		p = IObuff + STRLEN(IObuff);
		if (after_pathsep(IObuff, p) && p[-1] == p[-2])
		    // path ends with '//', use full path
		    if ((p = make_percent_swname(IObuff, fname)) != NULL)
		    {
			backup = modname(p, backup_ext, FALSE);
			vim_free(p);
		    }
#endif
		if (backup == NULL)
		{
		    rootname = get_file_in_dir(fname, IObuff);
		    if (rootname == NULL)
			backup = NULL;
		    else
		    {
			backup = buf_modname(
				(buf->b_p_sn || buf->b_shortname),
						rootname, backup_ext, FALSE);
			vim_free(rootname);
		    }
		}

		if (backup != NULL)
		{
		    // If we are not going to keep the backup file, don't
		    // delete an existing one, try to use another name.
		    // Change one character, just before the extension.
		    if (!p_bk && mch_getperm(backup) >= 0)
		    {
			p = backup + STRLEN(backup) - 1 - STRLEN(backup_ext);
			if (p < backup)	// empty file name ???
			    p = backup;
			*p = 'z';
			while (*p > 'a' && mch_getperm(backup) >= 0)
			    --*p;
			// They all exist??? Must be something wrong!
			if (*p == 'a')
			    VIM_CLEAR(backup);
		    }
		}
		if (backup != NULL)
		{
		    // Delete any existing backup and move the current version
		    // to the backup.	For safety, we don't remove the backup
		    // until the write has finished successfully. And if the
		    // 'backup' option is set, leave it around.

		    // If the renaming of the original file to the backup file
		    // works, quit here.
		    if (vim_rename(fname, backup) == 0)
			break;

		    VIM_CLEAR(backup);   // don't do the rename below
		}
	    }
	    if (backup == NULL && !forceit)
	    {
		errmsg = (char_u *)_(e_cant_make_backup_file_add_bang_to_write_anyway);
		goto fail;
	    }
	}
    }

#if defined(UNIX)
    // When using ":w!" and the file was read-only: make it writable
    if (forceit && perm >= 0 && !(perm & 0200) && st_old.st_uid == getuid()
				     && vim_strchr(p_cpo, CPO_FWRITE) == NULL)
    {
	perm |= 0200;
	(void)mch_setperm(fname, perm);
	made_writable = TRUE;
    }
#endif

    // When using ":w!" and writing to the current file, 'readonly' makes no
    // sense, reset it, unless 'Z' appears in 'cpoptions'.
    if (forceit && overwriting && vim_strchr(p_cpo, CPO_KEEPRO) == NULL)
    {
	buf->b_p_ro = FALSE;
	need_maketitle = TRUE;	    // set window title later
	status_redraw_all();	    // redraw status lines later
    }

    if (end > buf->b_ml.ml_line_count)
	end = buf->b_ml.ml_line_count;
    if (buf->b_ml.ml_flags & ML_EMPTY)
	start = end + 1;

    // If the original file is being overwritten, there is a small chance that
    // we crash in the middle of writing. Therefore the file is preserved now.
    // This makes all block numbers positive so that recovery does not need
    // the original file.
    // Don't do this if there is a backup file and we are exiting.
    if (reset_changed && !newfile && overwriting
					      && !(exiting && backup != NULL))
    {
	ml_preserve(buf, FALSE);
	if (got_int)
	{
	    errmsg = (char_u *)_(e_interrupted);
	    goto restore_backup;
	}
    }

#ifdef VMS
    vms_remove_version(fname); // remove version
#endif
    // Default: write the file directly.  May write to a temp file for
    // multi-byte conversion.
    wfname = fname;

    // Check for forced 'fileencoding' from "++opt=val" argument.
    if (eap != NULL && eap->force_enc != 0)
    {
	fenc = eap->cmd + eap->force_enc;
	fenc = enc_canonize(fenc);
	fenc_tofree = fenc;
    }
    else
	fenc = buf->b_p_fenc;

    // Check if the file needs to be converted.
    converted = need_conversion(fenc);

    // Check if UTF-8 to UCS-2/4 or Latin1 conversion needs to be done.  Or
    // Latin1 to Unicode conversion.  This is handled in buf_write_bytes().
    // Prepare the flags for it and allocate bw_conv_buf when needed.
    if (converted && (enc_utf8 || STRCMP(p_enc, "latin1") == 0))
    {
	wb_flags = get_fio_flags(fenc);
	if (wb_flags & (FIO_UCS2 | FIO_UCS4 | FIO_UTF16 | FIO_UTF8))
	{
	    // Need to allocate a buffer to translate into.
	    if (wb_flags & (FIO_UCS2 | FIO_UTF16 | FIO_UTF8))
		write_info.bw_conv_buflen = bufsize * 2;
	    else // FIO_UCS4
		write_info.bw_conv_buflen = bufsize * 4;
	    write_info.bw_conv_buf = alloc(write_info.bw_conv_buflen);
	    if (write_info.bw_conv_buf == NULL)
		end = 0;
	}
    }

#ifdef MSWIN
    if (converted && wb_flags == 0 && (wb_flags = get_win_fio_flags(fenc)) != 0)
    {
	// Convert UTF-8 -> UCS-2 and UCS-2 -> DBCS.  Worst-case * 4:
	write_info.bw_conv_buflen = bufsize * 4;
	write_info.bw_conv_buf = alloc(write_info.bw_conv_buflen);
	if (write_info.bw_conv_buf == NULL)
	    end = 0;
    }
#endif

#ifdef MACOS_CONVERT
    if (converted && wb_flags == 0 && (wb_flags = get_mac_fio_flags(fenc)) != 0)
    {
	write_info.bw_conv_buflen = bufsize * 3;
	write_info.bw_conv_buf = alloc(write_info.bw_conv_buflen);
	if (write_info.bw_conv_buf == NULL)
	    end = 0;
    }
#endif

#if defined(FEAT_EVAL) || defined(USE_ICONV)
    if (converted && wb_flags == 0)
    {
# ifdef USE_ICONV
	// Use iconv() conversion when conversion is needed and it's not done
	// internally.
	write_info.bw_iconv_fd = (iconv_t)my_iconv_open(fenc,
					enc_utf8 ? (char_u *)"utf-8" : p_enc);
	if (write_info.bw_iconv_fd != (iconv_t)-1)
	{
	    // We're going to use iconv(), allocate a buffer to convert in.
	    write_info.bw_conv_buflen = bufsize * ICONV_MULT;
	    write_info.bw_conv_buf = alloc(write_info.bw_conv_buflen);
	    if (write_info.bw_conv_buf == NULL)
		end = 0;
	    write_info.bw_first = TRUE;
	}
#  ifdef FEAT_EVAL
	else
#  endif
# endif

# ifdef FEAT_EVAL
	    // When the file needs to be converted with 'charconvert' after
	    // writing, write to a temp file instead and let the conversion
	    // overwrite the original file.
	    if (*p_ccv != NUL)
	    {
		wfname = vim_tempname('w', FALSE);
		if (wfname == NULL)	// Can't write without a tempfile!
		{
		    errmsg = (char_u *)_(e_cant_find_temp_file_for_writing);
		    goto restore_backup;
		}
	    }
# endif
    }
#endif
    if (converted && wb_flags == 0
#ifdef USE_ICONV
	    && write_info.bw_iconv_fd == (iconv_t)-1
# endif
# ifdef FEAT_EVAL
	    && wfname == fname
# endif
	    )
    {
	if (!forceit)
	{
	    errmsg = (char_u *)_(e_cannot_convert_add_bang_to_write_without_conversion);
	    goto restore_backup;
	}
	notconverted = TRUE;
    }

    // If conversion is taking place, we may first pretend to write and check
    // for conversion errors.  Then loop again to write for real.
    // When not doing conversion this writes for real right away.
    for (checking_conversion = TRUE; ; checking_conversion = FALSE)
    {
	// There is no need to check conversion when:
	// - there is no conversion
	// - we make a backup file, that can be restored in case of conversion
	//   failure.
	if (!converted || dobackup)
	    checking_conversion = FALSE;

	if (checking_conversion)
	{
	    // Make sure we don't write anything.
	    fd = -1;
	    write_info.bw_fd = fd;
	}
	else
	{
#ifdef HAVE_FTRUNCATE
# define TRUNC_ON_OPEN 0
#else
# define TRUNC_ON_OPEN O_TRUNC
#endif
	    // Open the file "wfname" for writing.
	    // We may try to open the file twice: If we can't write to the file
	    // and forceit is TRUE we delete the existing file and try to
	    // create a new one. If this still fails we may have lost the
	    // original file!  (this may happen when the user reached his
	    // quotum for number of files).
	    // Appending will fail if the file does not exist and forceit is
	    // FALSE.
	    while ((fd = mch_open((char *)wfname, O_WRONLY | O_EXTRA | (append
				? (forceit ? (O_APPEND | O_CREAT) : O_APPEND)
				: (O_CREAT | TRUNC_ON_OPEN))
				, perm < 0 ? 0666 : (perm & 0777))) < 0)
	    {
		// A forced write will try to create a new file if the old one
		// is still readonly. This may also happen when the directory
		// is read-only. In that case the mch_remove() will fail.
		if (errmsg == NULL)
		{
#ifdef UNIX
		    stat_T	st;

		    // Don't delete the file when it's a hard or symbolic link.
		    if ((!newfile && st_old.st_nlink > 1)
			    || (mch_lstat((char *)fname, &st) == 0
				&& (st.st_dev != st_old.st_dev
				    || st.st_ino != st_old.st_ino)))
			errmsg =
			      (char_u *)_(e_cant_open_linked_file_for_writing);
		    else
#endif
		    {
			errmsg = (char_u *)_(e_cant_open_file_for_writing);
			if (forceit && vim_strchr(p_cpo, CPO_FWRITE) == NULL
								  && perm >= 0)
			{
#ifdef UNIX
			    // we write to the file, thus it should be marked
			    // writable after all
			    if (!(perm & 0200))
				made_writable = TRUE;
			    perm |= 0200;
			    if (st_old.st_uid != getuid()
						  || st_old.st_gid != getgid())
				perm &= 0777;
#endif
			    if (!append)  // don't remove when appending
				mch_remove(wfname);
			    continue;
			}
		    }
		}

restore_backup:
		{
		    stat_T	st;

		    // If we failed to open the file, we don't need a backup.
		    // Throw it away.  If we moved or removed the original file
		    // try to put the backup in its place.
		    if (backup != NULL && wfname == fname)
		    {
			if (backup_copy)
			{
			    // There is a small chance that we removed the
			    // original, try to move the copy in its place.
			    // This may not work if the vim_rename() fails.
			    // In that case we leave the copy around.

			    // If file does not exist, put the copy in its
			    // place
			    if (mch_stat((char *)fname, &st) < 0)
				vim_rename(backup, fname);
			    // if original file does exist throw away the copy
			    if (mch_stat((char *)fname, &st) >= 0)
				mch_remove(backup);
			}
			else
			{
			    // try to put the original file back
			    vim_rename(backup, fname);
			}
		    }

		    // if original file no longer exists give an extra warning
		    if (!newfile && mch_stat((char *)fname, &st) < 0)
			end = 0;
		}

		if (wfname != fname)
		    vim_free(wfname);
		goto fail;
	    }
	    write_info.bw_fd = fd;

#if defined(UNIX)
	    {
		stat_T	st;

		// Double check we are writing the intended file before making
		// any changes.
		if (overwriting
			&& (!dobackup || backup_copy)
			&& fname == wfname
			&& perm >= 0
			&& mch_fstat(fd, &st) == 0
			&& st.st_ino != st_old.st_ino)
		{
		    close(fd);
		    errmsg = (char_u *)_(e_file_changed_while_writing);
		    goto fail;
		}
	    }
#endif
#ifdef HAVE_FTRUNCATE
	    if (!append)
		vim_ignored = ftruncate(fd, (off_t)0);
#endif

#if defined(MSWIN)
	    if (backup != NULL && overwriting && !append)
		(void)mch_copy_file_attribute(backup, wfname);

	    if (!overwriting && !append)
	    {
		if (buf->b_ffname != NULL)
		    (void)mch_copy_file_attribute(buf->b_ffname, wfname);
		// Should copy resource fork
	    }
#endif

#ifdef FEAT_CRYPT
	    if (*buf->b_p_key != NUL && !filtering)
	    {
		char_u		*header;
		int		header_len;

		buf->b_cryptstate = crypt_create_for_writing(
						      crypt_get_method_nr(buf),
					   buf->b_p_key, &header, &header_len);
		if (buf->b_cryptstate == NULL || header == NULL)
		    end = 0;
		else
		{
		    // Write magic number, so that Vim knows how this file is
		    // encrypted when reading it back.
		    write_info.bw_buf = header;
		    write_info.bw_len = header_len;
		    write_info.bw_flags = FIO_NOCONVERT;
		    if (buf_write_bytes(&write_info) == FAIL)
			end = 0;
		    wb_flags |= FIO_ENCRYPTED;
		    vim_free(header);
		}
	    }
#endif
	}
	errmsg = NULL;

	write_info.bw_buf = buffer;
	nchars = 0;

	// use "++bin", "++nobin" or 'binary'
	if (eap != NULL && eap->force_bin != 0)
	    write_bin = (eap->force_bin == FORCE_BIN);
	else
	    write_bin = buf->b_p_bin;

	// The BOM is written just after the encryption magic number.
	// Skip it when appending and the file already existed, the BOM only
	// makes sense at the start of the file.
	if (buf->b_p_bomb && !write_bin && (!append || perm < 0))
	{
	    write_info.bw_len = make_bom(buffer, fenc);
	    if (write_info.bw_len > 0)
	    {
		// don't convert, do encryption
		write_info.bw_flags = FIO_NOCONVERT | wb_flags;
		if (buf_write_bytes(&write_info) == FAIL)
		    end = 0;
		else
		    nchars += write_info.bw_len;
	    }
	}
	write_info.bw_start_lnum = start;

#ifdef FEAT_PERSISTENT_UNDO
	write_undo_file = (buf->b_p_udf
			    && overwriting
			    && !append
			    && !filtering
# ifdef CRYPT_NOT_INPLACE
			    // writing undo file requires
			    // crypt_encode_inplace()
			    && (buf->b_cryptstate == NULL
				|| crypt_works_inplace(buf->b_cryptstate))
# endif
			    && reset_changed
			    && !checking_conversion);
# ifdef CRYPT_NOT_INPLACE
	// remove undo file if encrypting it is not possible
	if (buf->b_p_udf
		&& overwriting
		&& !append
		&& !filtering
		&& !checking_conversion
		&& buf->b_cryptstate != NULL
		&& !crypt_works_inplace(buf->b_cryptstate))
	    u_undofile_reset_and_delete(buf);
# endif
	if (write_undo_file)
	    // Prepare for computing the hash value of the text.
	    sha256_start(&sha_ctx);
#endif

	write_info.bw_len = bufsize;
	write_info.bw_flags = wb_flags;
	fileformat = get_fileformat_force(buf, eap);
	s = buffer;
	len = 0;
	for (lnum = start; lnum <= end; ++lnum)
	{
	    // The next while loop is done once for each character written.
	    // Keep it fast!
	    ptr = ml_get_buf(buf, lnum, FALSE) - 1;
#ifdef FEAT_PERSISTENT_UNDO
	    if (write_undo_file)
		sha256_update(&sha_ctx, ptr + 1,
					      (UINT32_T)(STRLEN(ptr + 1) + 1));
#endif
	    while ((c = *++ptr) != NUL)
	    {
		if (c == NL)
		    *s = NUL;		// replace newlines with NULs
		else if (c == CAR && fileformat == EOL_MAC)
		    *s = NL;		// Mac: replace CRs with NLs
		else
		    *s = c;
		++s;
		if (++len != bufsize)
		    continue;
#ifdef FEAT_CRYPT
		if (write_info.bw_fd > 0 && lnum == end
			&& (write_info.bw_flags & FIO_ENCRYPTED)
			&& *buf->b_p_key != NUL && !filtering
			&& *ptr == NUL)
		    write_info.bw_finish = TRUE;
 #endif
		if (buf_write_bytes(&write_info) == FAIL)
		{
		    end = 0;		// write error: break loop
		    break;
		}
		nchars += bufsize;
		s = buffer;
		len = 0;
		write_info.bw_start_lnum = lnum;
	    }
	    // write failed or last line has no EOL: stop here
	    if (end == 0
		    || (lnum == end
			&& (write_bin || !buf->b_p_fixeol)
			&& ((write_bin && lnum == buf->b_no_eol_lnum)
			    || (lnum == buf->b_ml.ml_line_count
							   && !buf->b_p_eol))))
	    {
		++lnum;			// written the line, count it
		no_eol = TRUE;
		break;
	    }
	    if (fileformat == EOL_UNIX)
		*s++ = NL;
	    else
	    {
		*s++ = CAR;		    // EOL_MAC or EOL_DOS: write CR
		if (fileformat == EOL_DOS)  // write CR-NL
		{
		    if (++len == bufsize)
		    {
			if (buf_write_bytes(&write_info) == FAIL)
			{
			    end = 0;	// write error: break loop
			    break;
			}
			nchars += bufsize;
			s = buffer;
			len = 0;
		    }
		    *s++ = NL;
		}
	    }
	    if (++len == bufsize && end)
	    {
		if (buf_write_bytes(&write_info) == FAIL)
		{
		    end = 0;		// write error: break loop
		    break;
		}
		nchars += bufsize;
		s = buffer;
		len = 0;

		ui_breakcheck();
		if (got_int)
		{
		    end = 0;		// Interrupted, break loop
		    break;
		}
	    }
#ifdef VMS
	    // On VMS there is a problem: newlines get added when writing
	    // blocks at a time. Fix it by writing a line at a time.
	    // This is much slower!
	    // Explanation: VAX/DECC RTL insists that records in some RMS
	    // structures end with a newline (carriage return) character, and
	    // if they don't it adds one.
	    // With other RMS structures it works perfect without this fix.
# ifndef MIN
// Older DECC compiler for VAX doesn't define MIN()
#  define MIN(a, b) ((a) < (b) ? (a) : (b))
# endif
	    if (buf->b_fab_rfm == FAB$C_VFC
		    || ((buf->b_fab_rat & (FAB$M_FTN | FAB$M_CR)) != 0))
	    {
		int b2write;

		buf->b_fab_mrs = (buf->b_fab_mrs == 0
			? MIN(4096, bufsize)
			: MIN(buf->b_fab_mrs, bufsize));

		b2write = len;
		while (b2write > 0)
		{
		    write_info.bw_len = MIN(b2write, buf->b_fab_mrs);
		    if (buf_write_bytes(&write_info) == FAIL)
		    {
			end = 0;
			break;
		    }
		    b2write -= MIN(b2write, buf->b_fab_mrs);
		}
		write_info.bw_len = bufsize;
		nchars += len;
		s = buffer;
		len = 0;
	    }
#endif
	}
	if (len > 0 && end > 0)
	{
	    write_info.bw_len = len;
#ifdef FEAT_CRYPT
	    if (write_info.bw_fd > 0 && lnum >= end
		    && (write_info.bw_flags & FIO_ENCRYPTED)
		    && *buf->b_p_key != NUL && !filtering)
		write_info.bw_finish = TRUE;
 #endif
	    if (buf_write_bytes(&write_info) == FAIL)
		end = 0;		    // write error
	    nchars += len;
	}

	if (!buf->b_p_fixeol && buf->b_p_eof)
	{
	    // write trailing CTRL-Z
	    (void)write_eintr(write_info.bw_fd, "\x1a", 1);
	    nchars++;
	}

	// Stop when writing done or an error was encountered.
	if (!checking_conversion || end == 0)
	    break;

	// If no error happened until now, writing should be ok, so loop to
	// really write the buffer.
    }

    // If we started writing, finish writing. Also when an error was
    // encountered.
    if (!checking_conversion)
    {
#if defined(UNIX) && defined(HAVE_FSYNC)
	// On many journaling file systems there is a bug that causes both the
	// original and the backup file to be lost when halting the system
	// right after writing the file.  That's because only the meta-data is
	// journalled.  Syncing the file slows down the system, but assures it
	// has been written to disk and we don't lose it.
	// For a device do try the fsync() but don't complain if it does not
	// work (could be a pipe).
	// If the 'fsync' option is FALSE, don't fsync().  Useful for laptops.
	if (p_fs && vim_fsync(fd) != 0 && !device)
	{
	    errmsg = (char_u *)_(e_fsync_failed);
	    end = 0;
	}
#endif

#if defined(HAVE_SELINUX) || defined(HAVE_SMACK) || defined(FEAT_XATTR)
	// Probably need to set the security context.
	if (!backup_copy)
	{
#if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
	    mch_copy_sec(backup, wfname);
#endif
#ifdef FEAT_XATTR
	    mch_copy_xattr(backup, wfname);
#endif
	}
#endif

#ifdef UNIX
	// When creating a new file, set its owner/group to that of the
	// original file.  Get the new device and inode number.
	if (backup != NULL && !backup_copy)
	{
# ifdef HAVE_FCHOWN
	    stat_T	st;

	    // Don't change the owner when it's already OK, some systems remove
	    // permission or ACL stuff.
	    if (mch_stat((char *)wfname, &st) < 0
		    || st.st_uid != st_old.st_uid
		    || st.st_gid != st_old.st_gid)
	    {
		// changing owner might not be possible
		vim_ignored = fchown(fd, st_old.st_uid, -1);
		// if changing group fails clear the group permissions
		if (fchown(fd, -1, st_old.st_gid) == -1 && perm > 0)
		    perm &= ~070;
	    }
# endif
	    buf_setino(buf);
	}
	else if (!buf->b_dev_valid)
	    // Set the inode when creating a new file.
	    buf_setino(buf);
#endif

#ifdef UNIX
	if (made_writable)
	    perm &= ~0200;	// reset 'w' bit for security reasons
#endif
#ifdef HAVE_FCHMOD
	// set permission of new file same as old file
	if (perm >= 0)
	    (void)mch_fsetperm(fd, perm);
#endif
	if (close(fd) != 0)
	{
	    errmsg = (char_u *)_(e_close_failed);
	    end = 0;
	}

#ifndef HAVE_FCHMOD
	// set permission of new file same as old file
	if (perm >= 0)
	    (void)mch_setperm(wfname, perm);
#endif
#ifdef HAVE_ACL
	// Probably need to set the ACL before changing the user (can't set the
	// ACL on a file the user doesn't own).
	// On Solaris, with ZFS and the aclmode property set to "discard" (the
	// default), chmod() discards all part of a file's ACL that don't
	// represent the mode of the file.  It's non-trivial for us to discover
	// whether we're in that situation, so we simply always re-set the ACL.
# ifndef HAVE_SOLARIS_ZFS_ACL
	if (!backup_copy)
# endif
	    mch_set_acl(wfname, acl);
#endif
#ifdef FEAT_CRYPT
	if (buf->b_cryptstate != NULL)
	{
	    crypt_free_state(buf->b_cryptstate);
	    buf->b_cryptstate = NULL;
	}
#endif

#if defined(FEAT_EVAL)
	if (wfname != fname)
	{
	    // The file was written to a temp file, now it needs to be
	    // converted with 'charconvert' to (overwrite) the output file.
	    if (end != 0)
	    {
		if (eval_charconvert(enc_utf8 ? (char_u *)"utf-8" : p_enc,
						  fenc, wfname, fname) == FAIL)
		{
		    write_info.bw_conv_error = TRUE;
		    end = 0;
		}
	    }
	    mch_remove(wfname);
	    vim_free(wfname);
	}
#endif
    }

    if (end == 0)
    {
	// Error encountered.
	if (errmsg == NULL)
	{
	    if (write_info.bw_conv_error)
	    {
		if (write_info.bw_conv_error_lnum == 0)
		    errmsg = (char_u *)_(e_write_error_conversion_failed_make_fenc_empty_to_override);
		else
		{
		    errmsg_allocated = TRUE;
		    errmsg = alloc(300);
		    vim_snprintf((char *)errmsg, 300, _(e_write_error_conversion_failed_in_line_nr_make_fenc_empty_to_override),
					 (long)write_info.bw_conv_error_lnum);
		}
	    }
	    else if (got_int)
		errmsg = (char_u *)_(e_interrupted);
	    else
		errmsg = (char_u *)_(e_write_error_file_system_full);
	}

	// If we have a backup file, try to put it in place of the new file,
	// because the new file is probably corrupt.  This avoids losing the
	// original file when trying to make a backup when writing the file a
	// second time.
	// When "backup_copy" is set we need to copy the backup over the new
	// file.  Otherwise rename the backup file.
	// If this is OK, don't give the extra warning message.
	if (backup != NULL)
	{
	    if (backup_copy)
	    {
		// This may take a while, if we were interrupted let the user
		// know we got the message.
		if (got_int)
		{
		    msg(_(e_interrupted));
		    out_flush();
		}
		if ((fd = mch_open((char *)backup, O_RDONLY | O_EXTRA, 0)) >= 0)
		{
		    if ((write_info.bw_fd = mch_open((char *)fname,
				    O_WRONLY | O_CREAT | O_TRUNC | O_EXTRA,
							   perm & 0777)) >= 0)
		    {
			// copy the file.
			write_info.bw_buf = smallbuf;
			write_info.bw_flags = FIO_NOCONVERT;
			while ((write_info.bw_len = read_eintr(fd, smallbuf,
						      SMALLBUFSIZE)) > 0)
			    if (buf_write_bytes(&write_info) == FAIL)
				break;

			if (close(write_info.bw_fd) >= 0
						   && write_info.bw_len == 0)
			    end = 1;		// success
		    }
		    close(fd);	// ignore errors for closing read file
		}
	    }
	    else
	    {
		if (vim_rename(backup, fname) == 0)
		    end = 1;
	    }
	}
	goto fail;
    }

    lnum -= start;	    // compute number of written lines
    --no_wait_return;	    // may wait for return now

#if !(defined(UNIX) || defined(VMS))
    fname = sfname;	    // use shortname now, for the messages
#endif
    if (!filtering)
    {
	msg_add_fname(buf, fname);	// put fname in IObuff with quotes
	c = FALSE;
	if (write_info.bw_conv_error)
	{
	    STRCAT(IObuff, _(" CONVERSION ERROR"));
	    c = TRUE;
	    if (write_info.bw_conv_error_lnum != 0)
		vim_snprintf_add((char *)IObuff, IOSIZE, _(" in line %ld;"),
			(long)write_info.bw_conv_error_lnum);
	}
	else if (notconverted)
	{
	    STRCAT(IObuff, _("[NOT converted]"));
	    c = TRUE;
	}
	else if (converted)
	{
	    STRCAT(IObuff, _("[converted]"));
	    c = TRUE;
	}
	if (device)
	{
	    STRCAT(IObuff, _("[Device]"));
	    c = TRUE;
	}
	else if (newfile)
	{
	    STRCAT(IObuff, new_file_message());
	    c = TRUE;
	}
	if (no_eol)
	{
	    msg_add_eol();
	    c = TRUE;
	}
	// may add [unix/dos/mac]
	if (msg_add_fileformat(fileformat))
	    c = TRUE;
#ifdef FEAT_CRYPT
	if (wb_flags & FIO_ENCRYPTED)
	{
	    crypt_append_msg(buf);
	    c = TRUE;
	}
#endif
	msg_add_lines(c, (long)lnum, nchars);	// add line/char count
	if (!shortmess(SHM_WRITE))
	{
	    if (append)
		STRCAT(IObuff, shortmess(SHM_WRI) ? _(" [a]") : _(" appended"));
	    else
		STRCAT(IObuff, shortmess(SHM_WRI) ? _(" [w]") : _(" written"));
	}

	set_keep_msg((char_u *)msg_trunc_attr((char *)IObuff, FALSE, 0), 0);
    }

    // When written everything correctly: reset 'modified'.  Unless not
    // writing to the original file and '+' is not in 'cpoptions'.
    if (reset_changed && whole && !append
	    && !write_info.bw_conv_error
	    && (overwriting || vim_strchr(p_cpo, CPO_PLUS) != NULL))
    {
	unchanged(buf, TRUE, FALSE);
	// b:changedtick may be incremented in unchanged() but that should not
	// trigger a TextChanged event.
	if (buf->b_last_changedtick + 1 == CHANGEDTICK(buf))
	    buf->b_last_changedtick = CHANGEDTICK(buf);
	u_unchanged(buf);
	u_update_save_nr(buf);
    }

    // If written to the current file, update the timestamp of the swap file
    // and reset the BF_WRITE_MASK flags. Also sets buf->b_mtime.
    if (overwriting)
    {
	ml_timestamp(buf);
	if (append)
	    buf->b_flags &= ~BF_NEW;
	else
	    buf->b_flags &= ~BF_WRITE_MASK;
    }

    // If we kept a backup until now, and we are in patch mode, then we make
    // the backup file our 'original' file.
    if (*p_pm && dobackup)
    {
	char *org = (char *)buf_modname((buf->b_p_sn || buf->b_shortname),
							  fname, p_pm, FALSE);

	if (backup != NULL)
	{
	    stat_T	st;

	    // If the original file does not exist yet
	    // the current backup file becomes the original file
	    if (org == NULL)
		emsg(_(e_patchmode_cant_save_original_file));
	    else if (mch_stat(org, &st) < 0)
	    {
		vim_rename(backup, (char_u *)org);
		VIM_CLEAR(backup);	    // don't delete the file
#ifdef UNIX
		set_file_time((char_u *)org, st_old.st_atime, st_old.st_mtime);
#endif
	    }
	}
	// If there is no backup file, remember that a (new) file was
	// created.
	else
	{
	    int empty_fd;

	    if (org == NULL
		    || (empty_fd = mch_open(org,
				      O_CREAT | O_EXTRA | O_EXCL | O_NOFOLLOW,
					perm < 0 ? 0666 : (perm & 0777))) < 0)
	      emsg(_(e_patchmode_cant_touch_empty_original_file));
	    else
	      close(empty_fd);
	}
	if (org != NULL)
	{
	    mch_setperm((char_u *)org, mch_getperm(fname) & 0777);
	    vim_free(org);
	}
    }

    // Remove the backup unless 'backup' option is set or there was a
    // conversion error.
    if (!p_bk && backup != NULL && !write_info.bw_conv_error
	    && mch_remove(backup) != 0)
	emsg(_(e_cant_delete_backup_file));

    goto nofail;

    // Finish up.  We get here either after failure or success.
fail:
    --no_wait_return;		// may wait for return now
nofail:

    // Done saving, we accept changed buffer warnings again
    buf->b_saving = FALSE;

    vim_free(backup);
    if (buffer != smallbuf)
	vim_free(buffer);
    vim_free(fenc_tofree);
    vim_free(write_info.bw_conv_buf);
#ifdef USE_ICONV
    if (write_info.bw_iconv_fd != (iconv_t)-1)
    {
	iconv_close(write_info.bw_iconv_fd);
	write_info.bw_iconv_fd = (iconv_t)-1;
    }
#endif
#ifdef HAVE_ACL
    mch_free_acl(acl);
#endif

    if (errmsg != NULL)
    {
	int numlen = errnum != NULL ? (int)STRLEN(errnum) : 0;

	attr = HL_ATTR(HLF_E);	// set highlight for error messages
	msg_add_fname(buf,
#ifndef UNIX
		sfname
#else
		fname
#endif
		     );		// put file name in IObuff with quotes
	if (STRLEN(IObuff) + STRLEN(errmsg) + numlen >= IOSIZE)
	    IObuff[IOSIZE - STRLEN(errmsg) - numlen - 1] = NUL;
	// If the error message has the form "is ...", put the error number in
	// front of the file name.
	if (errnum != NULL)
	{
	    STRMOVE(IObuff + numlen, IObuff);
	    mch_memmove(IObuff, errnum, (size_t)numlen);
	}
	STRCAT(IObuff, errmsg);
	emsg((char *)IObuff);
	if (errmsg_allocated)
	    vim_free(errmsg);

	retval = FAIL;
	if (end == 0)
	{
	    msg_puts_attr(_("\nWARNING: Original file may be lost or damaged\n"),
		    attr | MSG_HIST);
	    msg_puts_attr(_("don't quit the editor until the file is successfully written!"),
		    attr | MSG_HIST);

	    // Update the timestamp to avoid an "overwrite changed file"
	    // prompt when writing again.
	    if (mch_stat((char *)fname, &st_old) >= 0)
	    {
		buf_store_time(buf, &st_old, fname);
		buf->b_mtime_read = buf->b_mtime;
		buf->b_mtime_read_ns = buf->b_mtime_ns;
	    }
	}
    }
    msg_scroll = msg_save;

#ifdef FEAT_PERSISTENT_UNDO
    // When writing the whole file and 'undofile' is set, also write the undo
    // file.
    if (retval == OK && write_undo_file)
    {
	char_u	    hash[UNDO_HASH_SIZE];

	sha256_finish(&sha_ctx, hash);
	u_write_undo(NULL, FALSE, buf, hash);
    }
#endif

#ifdef FEAT_EVAL
    if (!should_abort(retval))
#else
    if (!got_int)
#endif
    {
	aco_save_T	aco;

	curbuf->b_no_eol_lnum = 0;  // in case it was set by the previous read

	// Apply POST autocommands.
	// Careful: The autocommands may call buf_write() recursively!
	// Only do this when a window was found for "buf".
	aucmd_prepbuf(&aco, buf);
	if (curbuf == buf)
	{
	    if (append)
		apply_autocmds_exarg(EVENT_FILEAPPENDPOST, fname, fname,
							   FALSE, curbuf, eap);
	    else if (filtering)
		apply_autocmds_exarg(EVENT_FILTERWRITEPOST, NULL, fname,
							   FALSE, curbuf, eap);
	    else if (reset_changed && whole)
		apply_autocmds_exarg(EVENT_BUFWRITEPOST, fname, fname,
							   FALSE, curbuf, eap);
	    else
		apply_autocmds_exarg(EVENT_FILEWRITEPOST, fname, fname,
							   FALSE, curbuf, eap);

	    // restore curwin/curbuf and a few other things
	    aucmd_restbuf(&aco);
	}

#ifdef FEAT_EVAL
	if (aborting())	    // autocmds may abort script processing
	    retval = FALSE;
#endif
    }

#ifdef FEAT_VIMINFO
    // Make sure marks will be written out to the viminfo file later, even when
    // the file is new.
    curbuf->b_marks_read = TRUE;
#endif

    got_int |= prev_got_int;

    return retval;
}