/* vi:set ts=8 sts=4 sw=4:
 *
 * 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.
 */

/*
 * quickfix.c: functions for quickfix mode, using a file with error messages
 */

#include "vim.h"

#if defined(FEAT_QUICKFIX) || defined(PROTO)

struct dir_stack_T
{
    struct dir_stack_T	*next;
    char_u		*dirname;
};

static struct dir_stack_T   *dir_stack = NULL;

/*
 * for each error the next struct is allocated and linked in a list
 */
struct qf_line
{
    struct qf_line  *qf_next;	/* pointer to next error in the list */
    struct qf_line  *qf_prev;	/* pointer to previous error in the list */
    linenr_T	     qf_lnum;	/* line number where the error occurred */
    int		     qf_fnum;	/* file number for the line */
    int		     qf_col;	/* column where the error occurred */
    int		     qf_nr;	/* error number */
    char_u	    *qf_text;	/* description of the error */
    char_u	     qf_virt_col; /* set to TRUE if qf_col is screen column */
    char_u	     qf_cleared;/* set to TRUE if line has been deleted */
    char_u	     qf_type;	/* type of the error (mostly 'E'); 1 for
				   :helpgrep */
    char_u	     qf_valid;	/* valid error message detected */
};

/*
 * There is a stack of error lists.
 */
#define LISTCOUNT   10

struct qf_list
{
    struct qf_line *qf_start;	/* pointer to the first error */
    struct qf_line *qf_ptr;	/* pointer to the current error */
    int  qf_count;		/* number of errors (0 means no error list) */
    int  qf_index;		/* current index in the error list */
    int  qf_nonevalid;		/* TRUE if not a single valid entry found */
} qf_lists[LISTCOUNT];

static int	qf_curlist = 0;	/* current error list */
static int	qf_listcount = 0;   /* current number of lists */

#define FMT_PATTERNS 9		/* maximum number of % recognized */

/*
 * Structure used to hold the info of one part of 'errorformat'
 */
struct eformat
{
    regprog_T	    *prog;	/* pre-formatted part of 'errorformat' */
    struct eformat  *next;	/* pointer to next (NULL if last) */
    char_u	    addr[FMT_PATTERNS]; /* indices of used % patterns */
    char_u	    prefix;	/* prefix of this format line: */
				/*   'D' enter directory */
				/*   'X' leave directory */
				/*   'A' start of multi-line message */
				/*   'E' error message */
				/*   'W' warning message */
				/*   'I' informational message */
				/*   'C' continuation line */
				/*   'Z' end of multi-line message */
				/*   'G' general, unspecific message */
				/*   'P' push file (partial) message */
				/*   'Q' pop/quit file (partial) message */
				/*   'O' overread (partial) message */
    char_u	    flags;	/* additional flags given in prefix */
				/*   '-' do not include this line */
};

static int qf_init_ext __ARGS((char_u *efile, buf_T *buf, char_u *errorformat, int newlist, linenr_T lnumfirst, linenr_T lnumlast));
static void	qf_new_list __ARGS((void));
static int	qf_add_entry __ARGS((struct qf_line **prevp, char_u *dir, char_u *fname, char_u *mesg, long lnum, int col, int virt_col, int nr, int type, int valid));
static void	qf_msg __ARGS((void));
static void	qf_free __ARGS((int idx));
static char_u	*qf_types __ARGS((int, int));
static int	qf_get_fnum __ARGS((char_u *, char_u *));
static char_u	*qf_push_dir __ARGS((char_u *, struct dir_stack_T **));
static char_u	*qf_pop_dir __ARGS((struct dir_stack_T **));
static char_u	*qf_guess_filepath __ARGS((char_u *));
static void	qf_fmt_text __ARGS((char_u *text, char_u *buf, int bufsize));
static void	qf_clean_dir_stack __ARGS((struct dir_stack_T **));
#ifdef FEAT_WINDOWS
static int	qf_win_pos_update __ARGS((int old_qf_index));
static buf_T	*qf_find_buf __ARGS((void));
static void	qf_update_buffer __ARGS((void));
static void	qf_fill_buffer __ARGS((void));
#endif
static char_u	*get_mef_name __ARGS((void));
static buf_T	*load_dummy_buffer __ARGS((char_u *fname));
static void	wipe_dummy_buffer __ARGS((buf_T *buf));
static void	unload_dummy_buffer __ARGS((buf_T *buf));

/*
 * Read the errorfile "efile" into memory, line by line, building the error
 * list.
 * Return -1 for error, number of errors for success.
 */
    int
qf_init(efile, errorformat, newlist)
    char_u	    *efile;
    char_u	    *errorformat;
    int		    newlist;		/* TRUE: start a new error list */
{
    if (efile == NULL)
	return FAIL;
    return qf_init_ext(efile, curbuf, errorformat, newlist,
						    (linenr_T)0, (linenr_T)0);
}

/*
 * Read the errorfile "efile" into memory, line by line, building the error
 * list.
 * Alternative: when "efile" is null read errors from buffer "buf".
 * Always use 'errorformat' from "buf" if there is a local value.
 * Then lnumfirst and lnumlast specify the range of lines to use.
 * Return -1 for error, number of errors for success.
 */
    static int
qf_init_ext(efile, buf, errorformat, newlist, lnumfirst, lnumlast)
    char_u	    *efile;
    buf_T	    *buf;
    char_u	    *errorformat;
    int		    newlist;		/* TRUE: start a new error list */
    linenr_T	    lnumfirst;		/* first line number to use */
    linenr_T	    lnumlast;		/* last line number to use */
{
    char_u	    *namebuf;
    char_u	    *errmsg;
    char_u	    *fmtstr = NULL;
    int		    col = 0;
    char_u	    use_virt_col = FALSE;
    int		    type = 0;
    int		    valid;
    linenr_T	    buflnum = lnumfirst;
    long	    lnum = 0L;
    int		    enr = 0;
    FILE	    *fd = NULL;
    struct qf_line  *qfprev = NULL;	/* init to make SASC shut up */
    char_u	    *efmp;
    struct eformat  *fmt_first = NULL;
    struct eformat  *fmt_last = NULL;
    struct eformat  *fmt_ptr;
    char_u	    *efm;
    char_u	    *ptr;
    char_u	    *srcptr;
    int		    len;
    int		    i;
    int		    round;
    int		    idx = 0;
    int		    multiline = FALSE;
    int		    multiignore = FALSE;
    int		    multiscan = FALSE;
    int		    retval = -1;	/* default: return error flag */
    char_u	    *directory = NULL;
    char_u	    *currfile = NULL;
    char_u	    *tail = NULL;
    struct dir_stack_T  *file_stack = NULL;
    regmatch_T	    regmatch;
    static struct fmtpattern
    {
	char_u	convchar;
	char	*pattern;
    }		    fmt_pat[FMT_PATTERNS] =
		    {
			{'f', "\\f\\+"},
			{'n', "\\d\\+"},
			{'l', "\\d\\+"},
			{'c', "\\d\\+"},
			{'t', "."},
			{'m', ".\\+"},
			{'r', ".*"},
			{'p', "[- .]*"},
			{'v', "\\d\\+"}
		    };

    namebuf = alloc(CMDBUFFSIZE + 1);
    errmsg = alloc(CMDBUFFSIZE + 1);
    if (namebuf == NULL || errmsg == NULL)
	goto qf_init_end;

    if (efile != NULL && (fd = mch_fopen((char *)efile, "r")) == NULL)
    {
	EMSG2(_(e_openerrf), efile);
	goto qf_init_end;
    }

    if (newlist || qf_curlist == qf_listcount)
	/* make place for a new list */
	qf_new_list();
    else if (qf_lists[qf_curlist].qf_count > 0)
	/* Adding to existing list, find last entry. */
	for (qfprev = qf_lists[qf_curlist].qf_start;
			    qfprev->qf_next != qfprev; qfprev = qfprev->qf_next)
	    ;

/*
 * Each part of the format string is copied and modified from errorformat to
 * regex prog.  Only a few % characters are allowed.
 */
    /* Use the local value of 'errorformat' if it's set. */
    if (errorformat == p_efm && *buf->b_p_efm != NUL)
	efm = buf->b_p_efm;
    else
	efm = errorformat;
    /*
     * Get some space to modify the format string into.
     */
    i = (FMT_PATTERNS * 3) + ((int)STRLEN(efm) << 2);
    for (round = FMT_PATTERNS; round > 0; )
	i += (int)STRLEN(fmt_pat[--round].pattern);
#ifdef COLON_IN_FILENAME
    i += 12; /* "%f" can become twelve chars longer */
#else
    i += 2; /* "%f" can become two chars longer */
#endif
    if ((fmtstr = alloc(i)) == NULL)
	goto error2;

    while (efm[0])
    {
	/*
	 * Allocate a new eformat structure and put it at the end of the list
	 */
	fmt_ptr = (struct eformat *)alloc((unsigned)sizeof(struct eformat));
	if (fmt_ptr == NULL)
	    goto error2;
	if (fmt_first == NULL)	    /* first one */
	    fmt_first = fmt_ptr;
	else
	    fmt_last->next = fmt_ptr;
	fmt_last = fmt_ptr;
	fmt_ptr->prefix = NUL;
	fmt_ptr->flags = NUL;
	fmt_ptr->next = NULL;
	fmt_ptr->prog = NULL;
	for (round = FMT_PATTERNS; round > 0; )
	    fmt_ptr->addr[--round] = NUL;
	/* round is 0 now */

	/*
	 * Isolate one part in the 'errorformat' option
	 */
	for (len = 0; efm[len] != NUL && efm[len] != ','; ++len)
	    if (efm[len] == '\\' && efm[len + 1] != NUL)
		++len;

	/*
	 * Build regexp pattern from current 'errorformat' option
	 */
	ptr = fmtstr;
	*ptr++ = '^';
	for (efmp = efm; efmp < efm + len; ++efmp)
	{
	    if (*efmp == '%')
	    {
		++efmp;
		for (idx = 0; idx < FMT_PATTERNS; ++idx)
		    if (fmt_pat[idx].convchar == *efmp)
			break;
		if (idx < FMT_PATTERNS)
		{
		    if (fmt_ptr->addr[idx])
		    {
			sprintf((char *)errmsg,
				_("E372: Too many %%%c in format string"), *efmp);
			EMSG(errmsg);
			goto error2;
		    }
		    if ((idx
				&& idx < 6
				&& vim_strchr((char_u *)"DXOPQ",
						     fmt_ptr->prefix) != NULL)
			    || (idx == 6
				&& vim_strchr((char_u *)"OPQ",
						    fmt_ptr->prefix) == NULL))
		    {
			sprintf((char *)errmsg,
				_("E373: Unexpected %%%c in format string"), *efmp);
			EMSG(errmsg);
			goto error2;
		    }
		    fmt_ptr->addr[idx] = (char_u)++round;
		    *ptr++ = '\\';
		    *ptr++ = '(';
#ifdef BACKSLASH_IN_FILENAME
		    if (*efmp == 'f')
		    {
			/* Also match "c:" in the file name, even when
			 * checking for a colon next: "%f:".
			 * "\%(\a:\)\=" */
			STRCPY(ptr, "\\%(\\a:\\)\\=");
			ptr += 10;
		    }
#endif
		    if (*efmp == 'f' && efmp[1] != NUL
					 && efmp[1] != '\\' && efmp[1] != '%')
		    {
			/* A file name may contain spaces, but this isn't in
			 * "\f".  use "[^x]\+" instead (x is next character) */
			*ptr++ = '[';
			*ptr++ = '^';
			*ptr++ = efmp[1];
			*ptr++ = ']';
			*ptr++ = '\\';
			*ptr++ = '+';
		    }
		    else
		    {
			srcptr = (char_u *)fmt_pat[idx].pattern;
			while ((*ptr = *srcptr++) != NUL)
			    ++ptr;
		    }
		    *ptr++ = '\\';
		    *ptr++ = ')';
		}
		else if (*efmp == '*')
		{
		    if (*++efmp == '[' || *efmp == '\\')
		    {
			if ((*ptr++ = *efmp) == '[')	/* %*[^a-z0-9] etc. */
			{
			    if (efmp[1] == '^')
				*ptr++ = *++efmp;
			    if (efmp < efm + len)
			    {
				*ptr++ = *++efmp;	    /* could be ']' */
				while (efmp < efm + len
					&& (*ptr++ = *++efmp) != ']')
				    /* skip */;
				if (efmp == efm + len)
				{
				    EMSG(_("E374: Missing ] in format string"));
				    goto error2;
				}
			    }
			}
			else if (efmp < efm + len)	/* %*\D, %*\s etc. */
			    *ptr++ = *++efmp;
			*ptr++ = '\\';
			*ptr++ = '+';
		    }
		    else
		    {
			/* TODO: scanf()-like: %*ud, %*3c, %*f, ... ? */
			sprintf((char *)errmsg,
				_("E375: Unsupported %%%c in format string"), *efmp);
			EMSG(errmsg);
			goto error2;
		    }
		}
		else if (vim_strchr((char_u *)"%\\.^$~[", *efmp) != NULL)
		    *ptr++ = *efmp;		/* regexp magic characters */
		else if (*efmp == '#')
		    *ptr++ = '*';
		else if (efmp == efm + 1)		/* analyse prefix */
		{
		    if (vim_strchr((char_u *)"+-", *efmp) != NULL)
			fmt_ptr->flags = *efmp++;
		    if (vim_strchr((char_u *)"DXAEWICZGOPQ", *efmp) != NULL)
			fmt_ptr->prefix = *efmp;
		    else
		    {
			sprintf((char *)errmsg,
				_("E376: Invalid %%%c in format string prefix"), *efmp);
			EMSG(errmsg);
			goto error2;
		    }
		}
		else
		{
		    sprintf((char *)errmsg,
			    _("E377: Invalid %%%c in format string"), *efmp);
		    EMSG(errmsg);
		    goto error2;
		}
	    }
	    else			/* copy normal character */
	    {
		if (*efmp == '\\' && efmp + 1 < efm + len)
		    ++efmp;
		else if (vim_strchr((char_u *)".*^$~[", *efmp) != NULL)
		    *ptr++ = '\\';	/* escape regexp atoms */
		if (*efmp)
		    *ptr++ = *efmp;
	    }
	}
	*ptr++ = '$';
	*ptr = NUL;
	if ((fmt_ptr->prog = vim_regcomp(fmtstr, RE_MAGIC + RE_STRING)) == NULL)
	    goto error2;
	/*
	 * Advance to next part
	 */
	efm = skip_to_option_part(efm + len);	/* skip comma and spaces */
    }
    if (fmt_first == NULL)	/* nothing found */
    {
	EMSG(_("E378: 'errorformat' contains no pattern"));
	goto error2;
    }

    /*
     * got_int is reset here, because it was probably set when killing the
     * ":make" command, but we still want to read the errorfile then.
     */
    got_int = FALSE;

    /* Always ignore case when looking for a matching error. */
    regmatch.rm_ic = TRUE;

    /*
     * Read the lines in the error file one by one.
     * Try to recognize one of the error formats in each line.
     */
    while (!got_int)
    {
	/* Get the next line. */
	if (fd == NULL)
	{
	    if (buflnum > lnumlast)
		break;
	    STRNCPY(IObuff, ml_get_buf(buf, buflnum++, FALSE), CMDBUFFSIZE - 2);
	}
	else if (fgets((char *)IObuff, CMDBUFFSIZE - 2, fd) == NULL)
	    break;

	IObuff[CMDBUFFSIZE - 2] = NUL;  /* for very long lines */
	if ((efmp = vim_strrchr(IObuff, '\n')) != NULL)
	    *efmp = NUL;
#ifdef USE_CRNL
	if ((efmp = vim_strrchr(IObuff, '\r')) != NULL)
	    *efmp = NUL;
#endif

	/*
	 * Try to match each part of 'errorformat' until we find a complete
	 * match or no match.
	 */
	valid = TRUE;
restofline:
	for (fmt_ptr = fmt_first; fmt_ptr != NULL; fmt_ptr = fmt_ptr->next)
	{
	    idx = fmt_ptr->prefix;
	    if (multiscan && vim_strchr((char_u *)"OPQ", idx) == NULL)
		continue;
	    namebuf[0] = NUL;
	    if (!multiscan)
		errmsg[0] = NUL;
	    lnum = 0;
	    col = 0;
	    use_virt_col = FALSE;
	    enr = -1;
	    type = 0;
	    tail = NULL;

	    regmatch.regprog = fmt_ptr->prog;
	    if (vim_regexec(&regmatch, IObuff, (colnr_T)0))
	    {
		if ((idx == 'C' || idx == 'Z') && !multiline)
		    continue;
		if (vim_strchr((char_u *)"EWI", idx) != NULL)
		    type = idx;
		else
		    type = 0;
		/*
		 * Extract error message data from matched line
		 */
		if ((i = (int)fmt_ptr->addr[0]) > 0)		/* %f */
		{
		    len = (int)(regmatch.endp[i] - regmatch.startp[i]);
		    STRNCPY(namebuf, regmatch.startp[i], len);
		    namebuf[len] = NUL;
		    if (vim_strchr((char_u *)"OPQ", idx) != NULL
			    && mch_getperm(namebuf) == -1)
			continue;
		}
		if ((i = (int)fmt_ptr->addr[1]) > 0)		/* %n */
		    enr = (int)atol((char *)regmatch.startp[i]);
		if ((i = (int)fmt_ptr->addr[2]) > 0)		/* %l */
		    lnum = atol((char *)regmatch.startp[i]);
		if ((i = (int)fmt_ptr->addr[3]) > 0)		/* %c */
		    col = (int)atol((char *)regmatch.startp[i]);
		if ((i = (int)fmt_ptr->addr[4]) > 0)		/* %t */
		    type = *regmatch.startp[i];
		if (fmt_ptr->flags ==  '+' && !multiscan)	/* %+ */
		    STRCPY(errmsg, IObuff);
		else if ((i = (int)fmt_ptr->addr[5]) > 0)	/* %m */
		{
		    len = (int)(regmatch.endp[i] - regmatch.startp[i]);
		    STRNCPY(errmsg, regmatch.startp[i], len);
		    errmsg[len] = NUL;
		}
		if ((i = (int)fmt_ptr->addr[6]) > 0)		/* %r */
		    tail = regmatch.startp[i];
		if ((i = (int)fmt_ptr->addr[7]) > 0)		/* %p */
		{
		    col = (int)(regmatch.endp[i] - regmatch.startp[i] + 1);
		    if (*((char_u *)regmatch.startp[i]) != TAB)
			use_virt_col = TRUE;
		}
		if ((i = (int)fmt_ptr->addr[8]) > 0)		/* %v */
		{
		    col = (int)atol((char *)regmatch.startp[i]);
		    use_virt_col = TRUE;
		}
		break;
	    }
	}
	multiscan = FALSE;
	if (!fmt_ptr || idx == 'D' || idx == 'X')
	{
	    if (fmt_ptr)
	    {
		if (idx == 'D')				/* enter directory */
		{
		    if (*namebuf == NUL)
		    {
			EMSG(_("E379: Missing or empty directory name"));
			goto error2;
		    }
		    if ((directory = qf_push_dir(namebuf, &dir_stack)) == NULL)
			goto error2;
		}
		else if (idx == 'X')			/* leave directory */
		    directory = qf_pop_dir(&dir_stack);
	    }
	    namebuf[0] = NUL;		/* no match found, remove file name */
	    lnum = 0;			/* don't jump to this line */
	    valid = FALSE;
	    STRCPY(errmsg, IObuff);	/* copy whole line to error message */
	    if (!fmt_ptr)
		multiline = multiignore = FALSE;
	}
	else if (fmt_ptr)
	{
	    if (vim_strchr((char_u *)"AEWI", idx) != NULL)
		multiline = TRUE;	/* start of a multi-line message */
	    else if (vim_strchr((char_u *)"CZ", idx) != NULL)
	    {				/* continuation of multi-line msg */
		if (qfprev == NULL)
		    goto error2;
		if (*errmsg && !multiignore)
		{
		    len = (int)STRLEN(qfprev->qf_text);
		    if ((ptr = alloc((unsigned)(len + STRLEN(errmsg) + 2)))
								    == NULL)
			goto error2;
		    STRCPY(ptr, qfprev->qf_text);
		    vim_free(qfprev->qf_text);
		    qfprev->qf_text = ptr;
		    *(ptr += len) = '\n';
		    STRCPY(++ptr, errmsg);
		}
		if (qfprev->qf_nr == -1)
		    qfprev->qf_nr = enr;
		if (vim_isprintc(type) && !qfprev->qf_type)
		    qfprev->qf_type = type;  /* only printable chars allowed */
		if (!qfprev->qf_lnum)
		    qfprev->qf_lnum = lnum;
		if (!qfprev->qf_col)
		    qfprev->qf_col = col;
		qfprev->qf_virt_col = use_virt_col;
		if (!qfprev->qf_fnum)
		    qfprev->qf_fnum = qf_get_fnum(directory,
					*namebuf || directory ? namebuf
					  : currfile && valid ? currfile : 0);
		if (idx == 'Z')
		    multiline = multiignore = FALSE;
		line_breakcheck();
		continue;
	    }
	    else if (vim_strchr((char_u *)"OPQ", idx) != NULL)
	    {
		/* global file names */
		valid = FALSE;
		if (*namebuf == NUL || mch_getperm(namebuf) >= 0)
		{
		    if (*namebuf && idx == 'P')
			currfile = qf_push_dir(namebuf, &file_stack);
		    else if (idx == 'Q')
			currfile = qf_pop_dir(&file_stack);
		    *namebuf = NUL;
		    if (tail && *tail)
		    {
			STRCPY(IObuff, skipwhite(tail));
			multiscan = TRUE;
			goto restofline;
		    }
		}
	    }
	    if (fmt_ptr->flags == '-')	/* generally exclude this line */
	    {
		if (multiline)
		    multiignore = TRUE;	/* also exclude continuation lines */
		continue;
	    }
	}

	if (qf_add_entry(&qfprev,
			directory,
			*namebuf || directory
			    ? namebuf
			    : currfile && valid ? currfile : NULL,
			errmsg,
			lnum,
			col,
			use_virt_col,
			enr,
			type,
			valid) == FAIL)
	    goto error2;
	line_breakcheck();
    }
    if (fd == NULL || !ferror(fd))
    {
	if (qf_lists[qf_curlist].qf_index == 0)	/* no valid entry found */
	{
	    qf_lists[qf_curlist].qf_ptr = qf_lists[qf_curlist].qf_start;
	    qf_lists[qf_curlist].qf_index = 1;
	    qf_lists[qf_curlist].qf_nonevalid = TRUE;
	}
	else
	{
	    qf_lists[qf_curlist].qf_nonevalid = FALSE;
	    if (qf_lists[qf_curlist].qf_ptr == NULL)
		qf_lists[qf_curlist].qf_ptr = qf_lists[qf_curlist].qf_start;
	}
	retval = qf_lists[qf_curlist].qf_count;	/* return number of matches */
	goto qf_init_ok;
    }
    EMSG(_(e_readerrf));
error2:
    qf_free(qf_curlist);
    qf_listcount--;
    if (qf_curlist > 0)
	--qf_curlist;
qf_init_ok:
    if (fd != NULL)
	fclose(fd);
    for (fmt_ptr = fmt_first; fmt_ptr != NULL; fmt_ptr = fmt_first)
    {
	fmt_first = fmt_ptr->next;
	vim_free(fmt_ptr->prog);
	vim_free(fmt_ptr);
    }
    qf_clean_dir_stack(&dir_stack);
    qf_clean_dir_stack(&file_stack);
qf_init_end:
    vim_free(namebuf);
    vim_free(errmsg);
    vim_free(fmtstr);

#ifdef FEAT_WINDOWS
    qf_update_buffer();
#endif

    return retval;
}

/*
 * Prepare for adding a new quickfix list.
 */
    static void
qf_new_list()
{
    int		i;

    /*
     * If the current entry is not the last entry, delete entries below
     * the current entry.  This makes it possible to browse in a tree-like
     * way with ":grep'.
     */
    while (qf_listcount > qf_curlist + 1)
	qf_free(--qf_listcount);

    /*
     * When the stack is full, remove to oldest entry
     * Otherwise, add a new entry.
     */
    if (qf_listcount == LISTCOUNT)
    {
	qf_free(0);
	for (i = 1; i < LISTCOUNT; ++i)
	    qf_lists[i - 1] = qf_lists[i];
	qf_curlist = LISTCOUNT - 1;
    }
    else
	qf_curlist = qf_listcount++;
    qf_lists[qf_curlist].qf_index = 0;
    qf_lists[qf_curlist].qf_count = 0;
}

/*
 * Add an entry to the end of the list of errors.
 * Returns OK or FAIL.
 */
    static int
qf_add_entry(prevp, dir, fname, mesg, lnum, col, virt_col, nr, type, valid)
    struct qf_line **prevp;	/* pointer to previously added entry or NULL */
    char_u	*dir;		/* optional directory name */
    char_u	*fname;		/* file name or NULL */
    char_u	*mesg;		/* message */
    long	lnum;		/* line number */
    int		col;		/* column */
    int		virt_col;	/* using virtual column */
    int		nr;		/* error number */
    int		type;		/* type character */
    int		valid;		/* valid entry */
{
    struct qf_line *qfp;

    if ((qfp = (struct qf_line *)alloc((unsigned)sizeof(struct qf_line)))
								      == NULL)
	return FAIL;
    qfp->qf_fnum = qf_get_fnum(dir, fname);
    if ((qfp->qf_text = vim_strsave(mesg)) == NULL)
    {
	vim_free(qfp);
	return FAIL;
    }
    qfp->qf_lnum = lnum;
    qfp->qf_col = col;
    qfp->qf_virt_col = virt_col;
    qfp->qf_nr = nr;
    if (type != 1 && !vim_isprintc(type)) /* only printable chars allowed */
	type = 0;
    qfp->qf_type = type;
    qfp->qf_valid = valid;

    if (qf_lists[qf_curlist].qf_count == 0)	/* first element in the list */
    {
	qf_lists[qf_curlist].qf_start = qfp;
	qfp->qf_prev = qfp;	/* first element points to itself */
    }
    else
    {
	qfp->qf_prev = *prevp;
	(*prevp)->qf_next = qfp;
    }
    qfp->qf_next = qfp;	/* last element points to itself */
    qfp->qf_cleared = FALSE;
    *prevp = qfp;
    ++qf_lists[qf_curlist].qf_count;
    if (qf_lists[qf_curlist].qf_index == 0 && qfp->qf_valid)
					    /* first valid entry */
    {
	qf_lists[qf_curlist].qf_index = qf_lists[qf_curlist].qf_count;
	qf_lists[qf_curlist].qf_ptr = qfp;
    }

    return OK;
}

/*
 * get buffer number for file "dir.name"
 */
    static int
qf_get_fnum(directory, fname)
    char_u   *directory;
    char_u   *fname;
{
    if (fname == NULL || *fname == NUL)		/* no file name */
	return 0;
    {
#ifdef RISCOS
	/* Name is reported as `main.c', but file is `c.main' */
	return ro_buflist_add(fname);
#else
	char_u	    *ptr;
	int	    fnum;

# ifdef VMS
	vms_remove_version(fname);
# endif
# ifdef BACKSLASH_IN_FILENAME
	if (directory != NULL)
	    slash_adjust(directory);
	slash_adjust(fname);
# endif
	if (directory != NULL && !vim_isAbsName(fname)
		&& (ptr = concat_fnames(directory, fname, TRUE)) != NULL)
	{
	    /*
	     * Here we check if the file really exists.
	     * This should normally be true, but if make works without
	     * "leaving directory"-messages we might have missed a
	     * directory change.
	     */
	    if (mch_getperm(ptr) < 0)
	    {
		vim_free(ptr);
		directory = qf_guess_filepath(fname);
		if (directory)
		    ptr = concat_fnames(directory, fname, TRUE);
		else
		    ptr = vim_strsave(fname);
	    }
	    /* Use concatenated directory name and file name */
	    fnum = buflist_add(ptr, 0);
	    vim_free(ptr);
	    return fnum;
	}
	return buflist_add(fname, 0);
#endif
    }
}

/*
 * push dirbuf onto the directory stack and return pointer to actual dir or
 * NULL on error
 */
    static char_u *
qf_push_dir(dirbuf, stackptr)
    char_u		*dirbuf;
    struct dir_stack_T	**stackptr;
{
    struct dir_stack_T  *ds_new;
    struct dir_stack_T  *ds_ptr;

    /* allocate new stack element and hook it in */
    ds_new = (struct dir_stack_T *)alloc((unsigned)sizeof(struct dir_stack_T));
    if (ds_new == NULL)
	return NULL;

    ds_new->next = *stackptr;
    *stackptr = ds_new;

    /* store directory on the stack */
    if (vim_isAbsName(dirbuf)
	    || (*stackptr)->next == NULL
	    || (*stackptr && dir_stack != *stackptr))
	(*stackptr)->dirname = vim_strsave(dirbuf);
    else
    {
	/* Okay we don't have an absolute path.
	 * dirbuf must be a subdir of one of the directories on the stack.
	 * Let's search...
	 */
	ds_new = (*stackptr)->next;
	(*stackptr)->dirname = NULL;
	while (ds_new)
	{
	    vim_free((*stackptr)->dirname);
	    (*stackptr)->dirname = concat_fnames(ds_new->dirname, dirbuf,
		    TRUE);
	    if (mch_isdir((*stackptr)->dirname) == TRUE)
		break;

	    ds_new = ds_new->next;
	}

	/* clean up all dirs we already left */
	while ((*stackptr)->next != ds_new)
	{
	    ds_ptr = (*stackptr)->next;
	    (*stackptr)->next = (*stackptr)->next->next;
	    vim_free(ds_ptr->dirname);
	    vim_free(ds_ptr);
	}

	/* Nothing found -> it must be on top level */
	if (ds_new == NULL)
	{
	    vim_free((*stackptr)->dirname);
	    (*stackptr)->dirname = vim_strsave(dirbuf);
	}
    }

    if ((*stackptr)->dirname != NULL)
	return (*stackptr)->dirname;
    else
    {
	ds_ptr = *stackptr;
	*stackptr = (*stackptr)->next;
	vim_free(ds_ptr);
	return NULL;
    }
}


/*
 * pop dirbuf from the directory stack and return previous directory or NULL if
 * stack is empty
 */
    static char_u *
qf_pop_dir(stackptr)
    struct dir_stack_T	**stackptr;
{
    struct dir_stack_T  *ds_ptr;

    /* TODO: Should we check if dirbuf is the directory on top of the stack?
     * What to do if it isn't? */

    /* pop top element and free it */
    if (*stackptr != NULL)
    {
	ds_ptr = *stackptr;
	*stackptr = (*stackptr)->next;
	vim_free(ds_ptr->dirname);
	vim_free(ds_ptr);
    }

    /* return NEW top element as current dir or NULL if stack is empty*/
    return *stackptr ? (*stackptr)->dirname : NULL;
}

/*
 * clean up directory stack
 */
    static void
qf_clean_dir_stack(stackptr)
    struct dir_stack_T	**stackptr;
{
    struct dir_stack_T  *ds_ptr;

    while ((ds_ptr = *stackptr) != NULL)
    {
	*stackptr = (*stackptr)->next;
	vim_free(ds_ptr->dirname);
	vim_free(ds_ptr);
    }
}

/*
 * Check in which directory of the directory stack the given file can be
 * found.
 * Returns a pointer to the directory name or NULL if not found
 * Cleans up intermediate directory entries.
 *
 * TODO: How to solve the following problem?
 * If we have the this directory tree:
 *     ./
 *     ./aa
 *     ./aa/bb
 *     ./bb
 *     ./bb/x.c
 * and make says:
 *     making all in aa
 *     making all in bb
 *     x.c:9: Error
 * Then qf_push_dir thinks we are in ./aa/bb, but we are in ./bb.
 * qf_guess_filepath will return NULL.
 */
    static char_u *
qf_guess_filepath(filename)
    char_u *filename;
{
    struct dir_stack_T     *ds_ptr;
    struct dir_stack_T     *ds_tmp;
    char_u		   *fullname;

    /* no dirs on the stack - there's nothing we can do */
    if (dir_stack == NULL)
	return NULL;

    ds_ptr = dir_stack->next;
    fullname = NULL;
    while (ds_ptr)
    {
	vim_free(fullname);
	fullname = concat_fnames(ds_ptr->dirname, filename, TRUE);

	/* If concat_fnames failed, just go on. The worst thing that can happen
	 * is that we delete the entire stack.
	 */
	if ((fullname != NULL) && (mch_getperm(fullname) >= 0))
	    break;

	ds_ptr = ds_ptr->next;
    }

    vim_free(fullname);

    /* clean up all dirs we already left */
    while (dir_stack->next != ds_ptr)
    {
	ds_tmp = dir_stack->next;
	dir_stack->next = dir_stack->next->next;
	vim_free(ds_tmp->dirname);
	vim_free(ds_tmp);
    }

    return ds_ptr==NULL? NULL: ds_ptr->dirname;

}

/*
 * jump to a quickfix line
 * if dir == FORWARD go "errornr" valid entries forward
 * if dir == BACKWARD go "errornr" valid entries backward
 * if dir == FORWARD_FILE go "errornr" valid entries files backward
 * if dir == BACKWARD_FILE go "errornr" valid entries files backward
 * else if "errornr" is zero, redisplay the same line
 * else go to entry "errornr"
 */
    void
qf_jump(dir, errornr, forceit)
    int		dir;
    int		errornr;
    int		forceit;
{
    struct qf_line	*qf_ptr;
    struct qf_line	*old_qf_ptr;
    int			qf_index;
    int			old_qf_fnum;
    int			old_qf_index;
    int			prev_index;
    static char_u	*e_no_more_items = (char_u *)N_("E553: No more items");
    char_u		*err = e_no_more_items;
    linenr_T		i;
    buf_T		*old_curbuf;
    linenr_T		old_lnum;
    char_u		*old_swb = p_swb;
    colnr_T		screen_col;
    colnr_T		char_col;
    char_u		*line;
#ifdef FEAT_WINDOWS
    int			opened_window = FALSE;
    win_T		*win;
    win_T		*altwin;
#endif
    int			print_message = TRUE;
    int			len;
#ifdef FEAT_FOLDING
    int			old_KeyTyped = KeyTyped; /* getting file may reset it */
#endif
    int			ok = OK;

    if (qf_curlist >= qf_listcount || qf_lists[qf_curlist].qf_count == 0)
    {
	EMSG(_(e_quickfix));
	return;
    }

    qf_ptr = qf_lists[qf_curlist].qf_ptr;
    old_qf_ptr = qf_ptr;
    qf_index = qf_lists[qf_curlist].qf_index;
    old_qf_index = qf_index;
    if (dir == FORWARD || dir == FORWARD_FILE)	    /* next valid entry */
    {
	while (errornr--)
	{
	    old_qf_ptr = qf_ptr;
	    prev_index = qf_index;
	    old_qf_fnum = qf_ptr->qf_fnum;
	    do
	    {
		if (qf_index == qf_lists[qf_curlist].qf_count
						   || qf_ptr->qf_next == NULL)
		{
		    qf_ptr = old_qf_ptr;
		    qf_index = prev_index;
		    if (err != NULL)
		    {
			EMSG(_(err));
			goto theend;
		    }
		    errornr = 0;
		    break;
		}
		++qf_index;
		qf_ptr = qf_ptr->qf_next;
	    } while ((!qf_lists[qf_curlist].qf_nonevalid && !qf_ptr->qf_valid)
		  || (dir == FORWARD_FILE && qf_ptr->qf_fnum == old_qf_fnum));
	    err = NULL;
	}
    }
    else if (dir == BACKWARD || dir == BACKWARD_FILE)  /* prev. valid entry */
    {
	while (errornr--)
	{
	    old_qf_ptr = qf_ptr;
	    prev_index = qf_index;
	    old_qf_fnum = qf_ptr->qf_fnum;
	    do
	    {
		if (qf_index == 1 || qf_ptr->qf_prev == NULL)
		{
		    qf_ptr = old_qf_ptr;
		    qf_index = prev_index;
		    if (err != NULL)
		    {
			EMSG(_(err));
			goto theend;
		    }
		    errornr = 0;
		    break;
		}
		--qf_index;
		qf_ptr = qf_ptr->qf_prev;
	    } while ((!qf_lists[qf_curlist].qf_nonevalid && !qf_ptr->qf_valid)
		  || (dir == BACKWARD_FILE && qf_ptr->qf_fnum == old_qf_fnum));
	    err = NULL;
	}
    }
    else if (errornr != 0)	/* go to specified number */
    {
	while (errornr < qf_index && qf_index > 1 && qf_ptr->qf_prev != NULL)
	{
	    --qf_index;
	    qf_ptr = qf_ptr->qf_prev;
	}
	while (errornr > qf_index && qf_index < qf_lists[qf_curlist].qf_count
						   && qf_ptr->qf_next != NULL)
	{
	    ++qf_index;
	    qf_ptr = qf_ptr->qf_next;
	}
    }

#ifdef FEAT_WINDOWS
    qf_lists[qf_curlist].qf_index = qf_index;
    if (qf_win_pos_update(old_qf_index))
	/* No need to print the error message if it's visible in the error
	 * window */
	print_message = FALSE;

    /*
     * For ":helpgrep" find a help window or open one.
     */
    if (qf_ptr->qf_type == 1 && !curwin->w_buffer->b_help)
    {
	win_T	*wp;
	int	n;

	for (wp = firstwin; wp != NULL; wp = wp->w_next)
	    if (wp->w_buffer != NULL && wp->w_buffer->b_help)
		break;
	if (wp != NULL && wp->w_buffer->b_nwindows > 0)
	    win_enter(wp, TRUE);
	else
	{
	    /*
	     * Split off help window; put it at far top if no position
	     * specified, the current window is vertically split and narrow.
	     */
	    n = WSP_HELP;
# ifdef FEAT_VERTSPLIT
	    if (cmdmod.split == 0 && curwin->w_width != Columns
						      && curwin->w_width < 80)
		n |= WSP_TOP;
# endif
	    if (win_split(0, n) == FAIL)
		goto theend;
	    opened_window = TRUE;	/* close it when fail */

	    if (curwin->w_height < p_hh)
		win_setheight((int)p_hh);
	}

	if (!p_im)
	    restart_edit = 0;	    /* don't want insert mode in help file */
    }

    /*
     * If currently in the quickfix window, find another window to show the
     * file in.
     */
    if (bt_quickfix(curbuf) && !opened_window)
    {
	/*
	 * If there is no file specified, we don't know where to go.
	 * But do advance, otherwise ":cn" gets stuck.
	 */
	if (qf_ptr->qf_fnum == 0)
	    goto theend;

	/*
	 * If there is only one window, create a new one above the quickfix
	 * window.
	 */
	if (firstwin == lastwin)
	{
	    if (win_split(0, WSP_ABOVE) == FAIL)
		goto failed;		/* not enough room for window */
	    opened_window = TRUE;	/* close it when fail */
	    p_swb = empty_option;	/* don't split again */
# ifdef FEAT_SCROLLBIND
	    curwin->w_p_scb = FALSE;
# endif
	}
	else
	{
	    /*
	     * Try to find a window that shows the right buffer.
	     * Default to the window just above the quickfix buffer.
	     */
	    win = curwin;
	    altwin = NULL;
	    for (;;)
	    {
		if (win->w_buffer->b_fnum == qf_ptr->qf_fnum)
		    break;
		if (win->w_prev == NULL)
		    win = lastwin;	/* wrap around the top */
		else
		    win = win->w_prev;	/* go to previous window */

		if (bt_quickfix(win->w_buffer))
		{
		    /* Didn't find it, go to the window before the quickfix
		     * window. */
		    if (altwin != NULL)
			win = altwin;
		    else if (curwin->w_prev != NULL)
			win = curwin->w_prev;
		    else
			win = curwin->w_next;
		    break;
		}

		/* Remember a usable window. */
		if (altwin == NULL && !win->w_p_pvw
					   && win->w_buffer->b_p_bt[0] == NUL)
		    altwin = win;
	    }

	    win_goto(win);
	}
    }
#endif

    /*
     * If there is a file name,
     * read the wanted file if needed, and check autowrite etc.
     */
    old_curbuf = curbuf;
    old_lnum = curwin->w_cursor.lnum;

    if (qf_ptr->qf_fnum != 0)
    {
	if (qf_ptr->qf_type == 1)
	{
	    /* Open help file (do_ecmd() will set b_help flag, readfile() will
	     * set b_p_ro flag). */
	    if (!can_abandon(curbuf, forceit))
	    {
		EMSG(_(e_nowrtmsg));
		ok = FALSE;
	    }
	    else
		ok = do_ecmd(qf_ptr->qf_fnum, NULL, NULL, NULL, (linenr_T)1,
						   ECMD_HIDE + ECMD_SET_HELP);
	}
	else
	    ok = buflist_getfile(qf_ptr->qf_fnum,
			    (linenr_T)1, GETF_SETMARK | GETF_SWITCH, forceit);
    }

    if (ok == OK)
    {
	/* When not switched to another buffer, still need to set pc mark */
	if (curbuf == old_curbuf)
	    setpcmark();

	/*
	 * Go to line with error, unless qf_lnum is 0.
	 */
	i = qf_ptr->qf_lnum;
	if (i > 0)
	{
	    if (i > curbuf->b_ml.ml_line_count)
		i = curbuf->b_ml.ml_line_count;
	    curwin->w_cursor.lnum = i;
	}
	if (qf_ptr->qf_col > 0)
	{
	    curwin->w_cursor.col = qf_ptr->qf_col - 1;
	    if (qf_ptr->qf_virt_col == TRUE)
	    {
		/*
		 * Check each character from the beginning of the error
		 * line up to the error column.  For each tab character
		 * found, reduce the error column value by the length of
		 * a tab character.
		 */
		line = ml_get_curline();
		screen_col = 0;
		for (char_col = 0; char_col < curwin->w_cursor.col; ++char_col)
		{
		    if (*line == NUL)
			break;
		    if (*line++ == '\t')
		    {
			curwin->w_cursor.col -= 7 - (screen_col % 8);
			screen_col += 8 - (screen_col % 8);
		    }
		    else
			++screen_col;
		}
	    }
	    check_cursor();
	}
	else
	    beginline(BL_WHITE | BL_FIX);

#ifdef FEAT_FOLDING
	if ((fdo_flags & FDO_QUICKFIX) && old_KeyTyped)
	    foldOpenCursor();
#endif
	if (print_message)
	{
	    /* Update the screen before showing the message */
	    update_topline_redraw();
	    sprintf((char *)IObuff, _("(%d of %d)%s%s: "), qf_index,
		    qf_lists[qf_curlist].qf_count,
		    qf_ptr->qf_cleared ? _(" (line deleted)") : "",
		    (char *)qf_types(qf_ptr->qf_type, qf_ptr->qf_nr));
	    /* Add the message, skipping leading whitespace and newlines. */
	    len = (int)STRLEN(IObuff);
	    qf_fmt_text(skipwhite(qf_ptr->qf_text), IObuff + len, IOSIZE - len);

	    /* Output the message.  Overwrite to avoid scrolling when the 'O'
	     * flag is present in 'shortmess'; But when not jumping, print the
	     * whole message. */
	    i = msg_scroll;
	    if (curbuf == old_curbuf && curwin->w_cursor.lnum == old_lnum)
		msg_scroll = TRUE;
	    else if (!msg_scrolled && shortmess(SHM_OVERALL))
		msg_scroll = FALSE;
	    msg_attr_keep(IObuff, 0, TRUE);
	    msg_scroll = i;
	}
    }
    else
    {
#ifdef FEAT_WINDOWS
	if (opened_window)
	    win_close(curwin, TRUE);    /* Close opened window */
#endif
	if (qf_ptr->qf_fnum != 0)
	{
	    /*
	     * Couldn't open file, so put index back where it was.  This could
	     * happen if the file was readonly and we changed something.
	     */
#ifdef FEAT_WINDOWS
failed:
#endif
	    qf_ptr = old_qf_ptr;
	    qf_index = old_qf_index;
	}
    }
theend:
    qf_lists[qf_curlist].qf_ptr = qf_ptr;
    qf_lists[qf_curlist].qf_index = qf_index;
#ifdef FEAT_WINDOWS
    if (p_swb != old_swb && opened_window)
    {
	/* Restore old 'switchbuf' value, but not when an autocommand or
	 * modeline has changed the value. */
	if (p_swb == empty_option)
	    p_swb = old_swb;
	else
	    free_string_option(old_swb);
    }
#endif
}

/*
 * ":clist": list all errors
 */
    void
qf_list(eap)
    exarg_T	*eap;
{
    buf_T		*buf;
    char_u		*fname;
    struct qf_line	*qfp;
    int			i;
    int			idx1 = 1;
    int			idx2 = -1;
    int			need_return = TRUE;
    int			last_printed = 1;
    char_u		*arg = eap->arg;
    int			all = eap->forceit;	/* if not :cl!, only show
						   recognised errors */

    if (qf_curlist >= qf_listcount || qf_lists[qf_curlist].qf_count == 0)
    {
	EMSG(_(e_quickfix));
	return;
    }
    if (!get_list_range(&arg, &idx1, &idx2) || *arg != NUL)
    {
	EMSG(_(e_trailing));
	return;
    }
    i = qf_lists[qf_curlist].qf_count;
    if (idx1 < 0)
	idx1 = (-idx1 > i) ? 0 : idx1 + i + 1;
    if (idx2 < 0)
	idx2 = (-idx2 > i) ? 0 : idx2 + i + 1;

    more_back_used = TRUE;
    if (qf_lists[qf_curlist].qf_nonevalid)
	all = TRUE;
    qfp = qf_lists[qf_curlist].qf_start;
    for (i = 1; !got_int && i <= qf_lists[qf_curlist].qf_count; )
    {
	if ((qfp->qf_valid || all) && idx1 <= i && i <= idx2)
	{
	    if (need_return)
	    {
		msg_putchar('\n');
		need_return = FALSE;
	    }
	    if (more_back == 0)
	    {
		fname = NULL;
		if (qfp->qf_fnum != 0
			      && (buf = buflist_findnr(qfp->qf_fnum)) != NULL)
		{
		    fname = buf->b_fname;
		    if (qfp->qf_type == 1)	/* :helpgrep */
			fname = gettail(fname);
		}
		if (fname == NULL)
		    sprintf((char *)IObuff, "%2d", i);
		else
		    sprintf((char *)IObuff, "%2d %s", i, (char *)fname);
		msg_outtrans_attr(IObuff, i == qf_lists[qf_curlist].qf_index
			? hl_attr(HLF_L) : hl_attr(HLF_D));
		if (qfp->qf_lnum == 0)
		    IObuff[0] = NUL;
		else if (qfp->qf_col == 0)
		    sprintf((char *)IObuff, ":%ld", qfp->qf_lnum);
		else
		    sprintf((char *)IObuff, ":%ld col %d",
						   qfp->qf_lnum, qfp->qf_col);
		sprintf((char *)IObuff + STRLEN(IObuff), "%s: ",
				  (char *)qf_types(qfp->qf_type, qfp->qf_nr));
		msg_puts_attr(IObuff, hl_attr(HLF_N));
		/* Remove newlines and leading whitespace from the text.
		 * For an unrecognized line keep the indent, the compiler may
		 * mark a word with ^^^^. */
		qf_fmt_text((fname != NULL || qfp->qf_lnum != 0)
				     ? skipwhite(qfp->qf_text) : qfp->qf_text,
							      IObuff, IOSIZE);
		msg_prt_line(IObuff);
		out_flush();		/* show one line at a time */
		need_return = TRUE;
		last_printed = i;
	    }
	}
	if (more_back)
	{
	    /* scrolling backwards from the more-prompt */
	    /* TODO: compute the number of items from the screen lines */
	    more_back = more_back * 2 - 1;
	    while (i > last_printed - more_back && i > idx1)
	    {
		do
		{
		    qfp = qfp->qf_prev;
		    --i;
		}
		while (i > idx1 && !qfp->qf_valid && !all);
	    }
	    more_back = 0;
	}
	else
	{
	    qfp = qfp->qf_next;
	    ++i;
	}
	ui_breakcheck();
    }
    more_back_used = FALSE;
}

/*
 * Remove newlines and leading whitespace from an error message.
 * Put the result in "buf[bufsize]".
 */
    static void
qf_fmt_text(text, buf, bufsize)
    char_u	*text;
    char_u	*buf;
    int		bufsize;
{
    int		i;
    char_u	*p = text;

    for (i = 0; *p != NUL && i < bufsize - 1; ++i)
    {
	if (*p == '\n')
	{
	    buf[i] = ' ';
	    while (*++p != NUL)
		if (!vim_iswhite(*p) && *p != '\n')
		    break;
	}
	else
	    buf[i] = *p++;
    }
    buf[i] = NUL;
}

/*
 * ":colder [count]": Up in the quickfix stack.
 * ":cnewer [count]": Down in the quickfix stack.
 */
    void
qf_age(eap)
    exarg_T	*eap;
{
    int		count;

    if (eap->addr_count != 0)
	count = eap->line2;
    else
	count = 1;
    while (count--)
    {
	if (eap->cmdidx == CMD_colder)
	{
	    if (qf_curlist == 0)
	    {
		EMSG(_("E380: At bottom of quickfix stack"));
		return;
	    }
	    --qf_curlist;
	}
	else
	{
	    if (qf_curlist >= qf_listcount - 1)
	    {
		EMSG(_("E381: At top of quickfix stack"));
		return;
	    }
	    ++qf_curlist;
	}
    }
    qf_msg();
}

    static void
qf_msg()
{
    smsg((char_u *)_("error list %d of %d; %d errors"),
	    qf_curlist + 1, qf_listcount, qf_lists[qf_curlist].qf_count);
#ifdef FEAT_WINDOWS
    qf_update_buffer();
#endif
}

/*
 * free the error list
 */
    static void
qf_free(idx)
    int		idx;
{
    struct qf_line *qfp;

    while (qf_lists[idx].qf_count)
    {
	qfp = qf_lists[idx].qf_start->qf_next;
	vim_free(qf_lists[idx].qf_start->qf_text);
	vim_free(qf_lists[idx].qf_start);
	qf_lists[idx].qf_start = qfp;
	--qf_lists[idx].qf_count;
    }
}

/*
 * qf_mark_adjust: adjust marks
 */
   void
qf_mark_adjust(line1, line2, amount, amount_after)
    linenr_T	line1;
    linenr_T	line2;
    long	amount;
    long	amount_after;
{
    int			i;
    struct qf_line	*qfp;
    int			idx;

    for (idx = 0; idx < qf_listcount; ++idx)
	if (qf_lists[idx].qf_count)
	    for (i = 0, qfp = qf_lists[idx].qf_start;
		       i < qf_lists[idx].qf_count; ++i, qfp = qfp->qf_next)
		if (qfp->qf_fnum == curbuf->b_fnum)
		{
		    if (qfp->qf_lnum >= line1 && qfp->qf_lnum <= line2)
		    {
			if (amount == MAXLNUM)
			    qfp->qf_cleared = TRUE;
			else
			    qfp->qf_lnum += amount;
		    }
		    else if (amount_after && qfp->qf_lnum > line2)
			qfp->qf_lnum += amount_after;
		}
}

/*
 * Make a nice message out of the error character and the error number:
 *  char    number	message
 *  e or E    0		" error"
 *  w or W    0		" warning"
 *  i or I    0		" info"
 *  0	      0		""
 *  other     0		" c"
 *  e or E    n		" error n"
 *  w or W    n		" warning n"
 *  i or I    n		" info n"
 *  0	      n		" error n"
 *  other     n		" c n"
 *  1	      x		""	:helpgrep
 */
    static char_u *
qf_types(c, nr)
    int c, nr;
{
    static char_u	buf[20];
    static char_u	cc[3];
    char_u		*p;

    if (c == 'W' || c == 'w')
	p = (char_u *)" warning";
    else if (c == 'I' || c == 'i')
	p = (char_u *)" info";
    else if (c == 'E' || c == 'e' || (c == 0 && nr > 0))
	p = (char_u *)" error";
    else if (c == 0 || c == 1)
	p = (char_u *)"";
    else
    {
	cc[0] = ' ';
	cc[1] = c;
	cc[2] = NUL;
	p = cc;
    }

    if (nr <= 0)
	return p;

    sprintf((char *)buf, "%s %3d", (char *)p, nr);
    return buf;
}

#if defined(FEAT_WINDOWS) || defined(PROTO)
/*
 * ":cwindow": open the quickfix window if we have errors to display,
 *	       close it if not.
 */
    void
ex_cwindow(eap)
    exarg_T	*eap;
{
    win_T	*win;

    /*
     * Look for an existing quickfix window.
     */
    for (win = firstwin; win != NULL; win = win->w_next)
	if (bt_quickfix(win->w_buffer))
	    break;

    /*
     * If a quickfix window is open but we have no errors to display,
     * close the window.  If a quickfix window is not open, then open
     * it if we have errors; otherwise, leave it closed.
     */
    if (qf_lists[qf_curlist].qf_nonevalid || qf_curlist >= qf_listcount)
    {
	if (win != NULL)
	    ex_cclose(eap);
    }
    else if (win == NULL)
	ex_copen(eap);
}

/*
 * ":cclose": close the window showing the list of errors.
 */
/*ARGSUSED*/
    void
ex_cclose(eap)
    exarg_T	*eap;
{
    win_T	*win;

    /*
     * Find existing quickfix window and close it.
     */
    for (win = firstwin; win != NULL; win = win->w_next)
	if (bt_quickfix(win->w_buffer))
	    break;

    if (win != NULL)
	win_close(win, FALSE);
}

/*
 * ":copen": open a window that shows the list of errors.
 */
    void
ex_copen(eap)
    exarg_T	*eap;
{
    int		height;
    buf_T	*buf;
    win_T	*win;

    if (eap->addr_count != 0)
	height = eap->line2;
    else
	height = QF_WINHEIGHT;

#ifdef FEAT_VISUAL
    reset_VIsual_and_resel();			/* stop Visual mode */
#endif
#ifdef FEAT_GUI
    need_mouse_correct = TRUE;
#endif

    /*
     * Find existing quickfix window, or open a new one.
     */
    for (win = firstwin; win != NULL; win = win->w_next)
	if (bt_quickfix(win->w_buffer))
	    break;
    if (win != NULL)
	win_goto(win);
    else
    {
	/* The current window becomes the previous window afterwards. */
	win = curwin;

	/* Create the new window at the very bottom. */
	win_goto(lastwin);
	if (win_split(height, WSP_BELOW) == FAIL)
	    return;		/* not enough room for window */
#ifdef FEAT_SCROLLBIND
	curwin->w_p_scb = FALSE;
#endif

	/*
	 * Find existing quickfix buffer, or create a new one.
	 */
	buf = qf_find_buf();
	if (buf == NULL)
	{
	    (void)do_ecmd(0, NULL, NULL, NULL, ECMD_ONE, ECMD_HIDE);
	    /* switch off 'swapfile' */
	    set_option_value((char_u *)"swf", 0L, NULL, OPT_LOCAL);
	    set_option_value((char_u *)"bt", 0L, (char_u *)"quickfix",
								   OPT_LOCAL);
	    set_option_value((char_u *)"bh", 0L, (char_u *)"delete", OPT_LOCAL);
	    set_option_value((char_u *)"diff", 0L, (char_u *)"", OPT_LOCAL);
	}
	else if (buf != curbuf)
	    set_curbuf(buf, DOBUF_GOTO);

	/* Only set the height when there is no window to the side. */
	if (curwin->w_width == Columns)
	    win_setheight(height);
	curwin->w_p_wfh = TRUE;	    /* set 'winfixheight' */
	if (win_valid(win))
	    prevwin = win;
    }

    /*
     * Fill the buffer with the quickfix list.
     */
    qf_fill_buffer();

    curwin->w_cursor.lnum = qf_lists[qf_curlist].qf_index;
    curwin->w_cursor.col = 0;
    check_cursor();
    update_topline();		/* scroll to show the line */
}

/*
 * Return the number of the current entry (line number in the quickfix
 * window).
 */
     linenr_T
qf_current_entry()
{
    return qf_lists[qf_curlist].qf_index;
}

/*
 * Update the cursor position in the quickfix window to the current error.
 * Return TRUE if there is a quickfix window.
 */
    static int
qf_win_pos_update(old_qf_index)
    int		old_qf_index;	/* previous qf_index or zero */
{
    win_T	*win;
    int		qf_index = qf_lists[qf_curlist].qf_index;

    /*
     * Put the cursor on the current error in the quickfix window, so that
     * it's viewable.
     */
    for (win = firstwin; win != NULL; win = win->w_next)
	if (bt_quickfix(win->w_buffer))
	    break;
    if (win != NULL
	    && qf_index <= win->w_buffer->b_ml.ml_line_count
	    && old_qf_index != qf_index)
    {
	win_T	*old_curwin = curwin;

	curwin = win;
	curbuf = win->w_buffer;
	if (qf_index > old_qf_index)
	{
	    curwin->w_redraw_top = old_qf_index;
	    curwin->w_redraw_bot = qf_index;
	}
	else
	{
	    curwin->w_redraw_top = qf_index;
	    curwin->w_redraw_bot = old_qf_index;
	}
	curwin->w_cursor.lnum = qf_index;
	curwin->w_cursor.col = 0;
	update_topline();		/* scroll to show the line */
	redraw_later(VALID);
	curwin->w_redr_status = TRUE;	/* update ruler */
	curwin = old_curwin;
	curbuf = curwin->w_buffer;
    }
    return win != NULL;
}

/*
 * Find quickfix buffer.
 */
    static buf_T *
qf_find_buf()
{
    buf_T	*buf;

    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
	if (bt_quickfix(buf))
	    break;
    return buf;
}

/*
 * Find the quickfix buffer.  If it exists, update the contents.
 */
    static void
qf_update_buffer()
{
    buf_T	*buf;
#ifdef FEAT_AUTOCMD
    aco_save_T	aco;
#else
    buf_T	*save_curbuf;
#endif

    /* Check if a buffer for the quickfix list exists.  Update it. */
    buf = qf_find_buf();
    if (buf != NULL)
    {
#ifdef FEAT_AUTOCMD
	/* set curwin/curbuf to buf and save a few things */
	aucmd_prepbuf(&aco, buf);
#else
	save_curbuf = curbuf;
	curbuf = buf;
#endif

	qf_fill_buffer();

#ifdef FEAT_AUTOCMD
	/* restore curwin/curbuf and a few other things */
	aucmd_restbuf(&aco);
#else
	curbuf = save_curbuf;
#endif

	(void)qf_win_pos_update(0);
    }
}

/*
 * Fill current buffer with quickfix errors, replacing any previous contents.
 * curbuf must be the quickfix buffer!
 */
    static void
qf_fill_buffer()
{
    linenr_T		lnum;
    struct qf_line	*qfp;
    buf_T		*errbuf;
    int			len;
    int			old_KeyTyped = KeyTyped;

    /* delete all existing lines */
    while ((curbuf->b_ml.ml_flags & ML_EMPTY) == 0)
	(void)ml_delete((linenr_T)1, FALSE);

    /* Check if there is anything to display */
    if (qf_curlist < qf_listcount)
    {
	/* Add one line for each error */
	qfp = qf_lists[qf_curlist].qf_start;
	for (lnum = 0; lnum < qf_lists[qf_curlist].qf_count; ++lnum)
	{
	    if (qfp->qf_fnum != 0
		    && (errbuf = buflist_findnr(qfp->qf_fnum)) != NULL
		    && errbuf->b_fname != NULL)
	    {
		if (qfp->qf_type == 1)	/* :helpgrep */
		    STRCPY(IObuff, gettail(errbuf->b_fname));
		else
		    STRCPY(IObuff, errbuf->b_fname);
		len = (int)STRLEN(IObuff);
	    }
	    else
		len = 0;
	    IObuff[len++] = '|';

	    if (qfp->qf_lnum > 0)
	    {
		sprintf((char *)IObuff + len, "%ld", qfp->qf_lnum);
		len += (int)STRLEN(IObuff + len);

		if (qfp->qf_col > 0)
		{
		    sprintf((char *)IObuff + len, " col %d", qfp->qf_col);
		    len += (int)STRLEN(IObuff + len);
		}

		sprintf((char *)IObuff + len, "%s",
				  (char *)qf_types(qfp->qf_type, qfp->qf_nr));
		len += (int)STRLEN(IObuff + len);
	    }
	    IObuff[len++] = '|';
	    IObuff[len++] = ' ';

	    /* Remove newlines and leading whitespace from the text.
	     * For an unrecognized line keep the indent, the compiler may
	     * mark a word with ^^^^. */
	    qf_fmt_text(len > 3 ? skipwhite(qfp->qf_text) : qfp->qf_text,
						  IObuff + len, IOSIZE - len);

	    if (ml_append(lnum, IObuff, (colnr_T)STRLEN(IObuff) + 1, FALSE)
								      == FAIL)
		break;
	    qfp = qfp->qf_next;
	}
	/* Delete the empty line which is now at the end */
	(void)ml_delete(lnum + 1, FALSE);
    }

    /* correct cursor position */
    check_lnums(TRUE);

    /* Set the 'filetype' to "qf" each time after filling the buffer.  This
     * resembles reading a file into a buffer, it's more logical when using
     * autocommands. */
    set_option_value((char_u *)"ft", 0L, (char_u *)"qf", OPT_LOCAL);
    curbuf->b_p_ma = FALSE;

#ifdef FEAT_AUTOCMD
    apply_autocmds(EVENT_BUFREADPOST, (char_u *)"quickfix", NULL,
							       FALSE, curbuf);
    apply_autocmds(EVENT_BUFWINENTER, (char_u *)"quickfix", NULL,
							       FALSE, curbuf);
#endif

    /* make sure it will be redrawn */
    redraw_curbuf_later(NOT_VALID);

    /* Restore KeyTyped, setting 'filetype' may reset it. */
    KeyTyped = old_KeyTyped;
}

#endif /* FEAT_WINDOWS */

/*
 * Return TRUE if "buf" is the quickfix buffer.
 */
    int
bt_quickfix(buf)
    buf_T	*buf;
{
    return (buf->b_p_bt[0] == 'q');
}

/*
 * Return TRUE if "buf" is a "nofile" or "acwrite" buffer.
 * This means the buffer name is not a file name.
 */
    int
bt_nofile(buf)
    buf_T	*buf;
{
    return (buf->b_p_bt[0] == 'n' && buf->b_p_bt[2] == 'f')
	    || buf->b_p_bt[0] == 'a';
}

/*
 * Return TRUE if "buf" is a "nowrite" or "nofile" buffer.
 */
    int
bt_dontwrite(buf)
    buf_T	*buf;
{
    return (buf->b_p_bt[0] == 'n');
}

    int
bt_dontwrite_msg(buf)
    buf_T	*buf;
{
    if (bt_dontwrite(buf))
    {
	EMSG(_("E382: Cannot write, 'buftype' option is set"));
	return TRUE;
    }
    return FALSE;
}

/*
 * Return TRUE if the buffer should be hidden, according to 'hidden', ":hide"
 * and 'bufhidden'.
 */
    int
buf_hide(buf)
    buf_T	*buf;
{
    /* 'bufhidden' overrules 'hidden' and ":hide", check it first */
    switch (buf->b_p_bh[0])
    {
	case 'u':		    /* "unload" */
	case 'w':		    /* "wipe" */
	case 'd': return FALSE;	    /* "delete" */
	case 'h': return TRUE;	    /* "hide" */
    }
    return (p_hid || cmdmod.hide);
}

/*
 * Return TRUE when using ":vimgrep" for ":grep".
 */
    int
grep_internal(cmdidx)
    cmdidx_T	cmdidx;
{
    return ((cmdidx == CMD_grep || cmdidx == CMD_grepadd)
	    && STRCMP("internal",
			*curbuf->b_p_gp == NUL ? p_gp : curbuf->b_p_gp) == 0);
}

/*
 * Used for ":make", ":grep" and ":grepadd".
 */
    void
ex_make(eap)
    exarg_T	*eap;
{
    char_u	*name;
    char_u	*cmd;
    unsigned	len;

    /* Redirect ":grep" to ":vimgrep" if 'grepprg' is "internal". */
    if (grep_internal(eap->cmdidx))
    {
	ex_vimgrep(eap);
	return;
    }

    autowrite_all();
    name = get_mef_name();
    if (name == NULL)
	return;
    mch_remove(name);	    /* in case it's not unique */

    /*
     * If 'shellpipe' empty: don't redirect to 'errorfile'.
     */
    len = (unsigned)STRLEN(p_shq) * 2 + (unsigned)STRLEN(eap->arg) + 1;
    if (*p_sp != NUL)
	len += (unsigned)STRLEN(p_sp) + (unsigned)STRLEN(name) + 3;
    cmd = alloc(len);
    if (cmd == NULL)
	return;
    sprintf((char *)cmd, "%s%s%s", (char *)p_shq, (char *)eap->arg,
							       (char *)p_shq);
    if (*p_sp != NUL)
	append_redir(cmd, p_sp, name);
    /*
     * Output a newline if there's something else than the :make command that
     * was typed (in which case the cursor is in column 0).
     */
    if (msg_col == 0)
	msg_didout = FALSE;
    msg_start();
    MSG_PUTS(":!");
    msg_outtrans(cmd);		/* show what we are doing */

    /* let the shell know if we are redirecting output or not */
    do_shell(cmd, *p_sp != NUL ? SHELL_DOOUT : 0);

#ifdef AMIGA
    out_flush();
		/* read window status report and redraw before message */
    (void)char_avail();
#endif

    if (qf_init(name, eap->cmdidx != CMD_make ? p_gefm : p_efm,
					       eap->cmdidx != CMD_grepadd) > 0
	    && !eap->forceit)
	qf_jump(0, 0, FALSE);		/* display first error */

    mch_remove(name);
    vim_free(name);
    vim_free(cmd);
}

/*
 * Return the name for the errorfile, in allocated memory.
 * Find a new unique name when 'makeef' contains "##".
 * Returns NULL for error.
 */
    static char_u *
get_mef_name()
{
    char_u	*p;
    char_u	*name;
    static int	start = -1;
    static int	off = 0;
#ifdef HAVE_LSTAT
    struct stat	sb;
#endif

    if (*p_mef == NUL)
    {
	name = vim_tempname('e');
	if (name == NULL)
	    EMSG(_(e_notmp));
	return name;
    }

    for (p = p_mef; *p; ++p)
	if (p[0] == '#' && p[1] == '#')
	    break;

    if (*p == NUL)
	return vim_strsave(p_mef);

    /* Keep trying until the name doesn't exist yet. */
    for (;;)
    {
	if (start == -1)
	    start = mch_get_pid();
	else
	    off += 19;

	name = alloc((unsigned)STRLEN(p_mef) + 30);
	if (name == NULL)
	    break;
	STRCPY(name, p_mef);
	sprintf((char *)name + (p - p_mef), "%d%d", start, off);
	STRCAT(name, p + 2);
	if (mch_getperm(name) < 0
#ifdef HAVE_LSTAT
		    /* Don't accept a symbolic link, its a security risk. */
		    && mch_lstat((char *)name, &sb) < 0
#endif
		)
	    break;
	vim_free(name);
    }
    return name;
}

/*
 * ":cc", ":crewind", ":cfirst" and ":clast".
 */
    void
ex_cc(eap)
    exarg_T	*eap;
{
    qf_jump(0,
	    eap->addr_count > 0
	    ? (int)eap->line2
	    : eap->cmdidx == CMD_cc
		? 0
		: (eap->cmdidx == CMD_crewind || eap->cmdidx == CMD_cfirst)
		    ? 1
		    : 32767,
	    eap->forceit);
}

/*
 * ":cnext", ":cnfile", ":cNext" and ":cprevious".
 */
    void
ex_cnext(eap)
    exarg_T	*eap;
{
    qf_jump(eap->cmdidx == CMD_cnext
	    ? FORWARD
	    : eap->cmdidx == CMD_cnfile
		? FORWARD_FILE
		: (eap->cmdidx == CMD_cpfile || eap->cmdidx == CMD_cNfile)
		    ? BACKWARD_FILE
		    : BACKWARD,
	    eap->addr_count > 0 ? (int)eap->line2 : 1, eap->forceit);
}

/*
 * ":cfile" command.
 */
    void
ex_cfile(eap)
    exarg_T	*eap;
{
    if (*eap->arg != NUL)
	set_string_option_direct((char_u *)"ef", -1, eap->arg, OPT_FREE);
    if (qf_init(p_ef, p_efm, TRUE) > 0 && eap->cmdidx == CMD_cfile)
	qf_jump(0, 0, eap->forceit);		/* display first error */
}

/*
 * ":vimgrep {pattern} file(s)"
 */
    void
ex_vimgrep(eap)
    exarg_T	*eap;
{
    regmmatch_T	regmatch;
    char_u	*save_cpo;
    int         fcount;
    char_u	**fnames;
    char_u      *s;
    char_u      *p;
    int		i;
    int         fi;
    struct qf_line *prevp = NULL;
    long	lnum;
    garray_T	ga;
    buf_T	*buf;
    int		duplicate_name = FALSE;
    int		using_dummy;
    int		found_match;
    int		first_match = TRUE;

    /* Make 'cpoptions' empty, the 'l' flag should not be used here. */
    save_cpo = p_cpo;
    p_cpo = empty_option;

    /* Get the search pattern: either white-separated or enclosed in // */
    regmatch.regprog = NULL;
    if (vim_isIDc(*eap->arg))
    {
	s = eap->arg;
	p = skiptowhite(s);
    }
    else
    {
	s = eap->arg + 1;
	p = skip_regexp(s, *eap->arg, TRUE, NULL);
	if (*p != *eap->arg)
	{
	    EMSG(_("E682: Invalid search pattern or delimiter"));
	    goto theend;
	}
    }
    if (*p != NUL)
	*p++ = NUL;
    regmatch.regprog = vim_regcomp(s, RE_MAGIC);
    if (regmatch.regprog == NULL)
	goto theend;
    regmatch.rmm_ic = FALSE;

    p = skipwhite(p);
    if (*p == NUL)
    {
	EMSG(_("E683: File name missing or invalid pattern"));
	goto theend;
    }

    if ((eap->cmdidx != CMD_grepadd && eap->cmdidx != CMD_vimgrepadd)
						|| qf_curlist == qf_listcount)
	/* make place for a new list */
	qf_new_list();
    else if (qf_lists[qf_curlist].qf_count > 0)
	/* Adding to existing list, find last entry. */
	for (prevp = qf_lists[qf_curlist].qf_start;
			    prevp->qf_next != prevp; prevp = prevp->qf_next)
	    ;

    /* parse the list of arguments */
    if (get_arglist(&ga, p) == FAIL)
	goto theend;
    i = gen_expand_wildcards(ga.ga_len, (char_u **)ga.ga_data,
				       &fcount, &fnames, EW_FILE|EW_NOTFOUND);
    ga_clear(&ga);
    if (i == FAIL)
	goto theend;
    if (fcount == 0)
    {
	EMSG(_(e_nomatch));
	goto theend;
    }

    for (fi = 0; fi < fcount && !got_int; ++fi)
    {
	buf = buflist_findname_exp(fnames[fi]);
	if (buf == NULL || buf->b_ml.ml_mfp == NULL)
	{
	    /* Remember that a buffer with this name already exists. */
	    duplicate_name = (buf != NULL);

	    /* Load file into a buffer, so that 'fileencoding' is detected,
	     * autocommands applied, etc. */
	    buf = load_dummy_buffer(fnames[fi]);
	    using_dummy = TRUE;
	}
	else
	    /* Use existing, loaded buffer. */
	    using_dummy = FALSE;
	if (buf == NULL)
	    smsg((char_u *)_("Cannot open file \"%s\""), fnames[fi]);
	else
	{
	    found_match = FALSE;
	    for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
	    {
		if (vim_regexec_multi(&regmatch, curwin, buf, lnum,
							      (colnr_T)0) > 0)
		{
		    if (qf_add_entry(&prevp,
				NULL,       /* dir */
				fnames[fi],
				ml_get_buf(buf,
				     regmatch.startpos[0].lnum + lnum, FALSE),
				regmatch.startpos[0].lnum + lnum,
				regmatch.startpos[0].col + 1,
				FALSE,      /* virt_col */
				0,          /* nr */
				0,          /* type */
				TRUE        /* valid */
				) == FAIL)
		    {
			got_int = TRUE;
			break;
		    }
		    else
			found_match = TRUE;
		}
		line_breakcheck();
		if (got_int)
		    break;
	    }

	    if (using_dummy)
	    {
		if (duplicate_name)
		    /* Never keep a dummy buffer if there is another buffer
		     * with the same name. */
		    wipe_dummy_buffer(buf);
		else if (!buf_hide(buf))
		{
		    /* When not hiding the buffer and no match was found we
		     * don't need to remember the buffer, wipe it out.  If
		     * there was a match and it wasn't the first one: only
		     * unload the buffer. */
		    if (!found_match)
			wipe_dummy_buffer(buf);
		    else if (!first_match)
			unload_dummy_buffer(buf);
		}
	    }
	    if (found_match)
		first_match = FALSE;
	}
    }

    FreeWild(fcount, fnames);

    qf_lists[qf_curlist].qf_nonevalid = FALSE;
    qf_lists[qf_curlist].qf_ptr = qf_lists[qf_curlist].qf_start;
    qf_lists[qf_curlist].qf_index = 1;

#ifdef FEAT_WINDOWS
    qf_update_buffer();
#endif

    /* Jump to first match. */
    if (qf_lists[qf_curlist].qf_count > 0)
	qf_jump(0, 0, FALSE);
    else
	EMSG2(_(e_nomatch2), s);

theend:
    vim_free(regmatch.regprog);

    /* Only resture 'cpo' when it wasn't set in the mean time. */
    if (p_cpo == empty_option)
	p_cpo = save_cpo;
    else
	free_string_option(save_cpo);
}

/*
 * Load file "fname" into a dummy buffer and return the buffer pointer.
 * Returns NULL if it fails.
 * Must call unload_dummy_buffer() or wipe_dummy_buffer() later!
 */
    static buf_T *
load_dummy_buffer(fname)
    char_u	*fname;
{
    buf_T	*newbuf;
    int		failed = TRUE;
#ifdef FEAT_AUTOCMD
    aco_save_T	aco;
#else
    buf_T	*old_curbuf = curbuf;
#endif

    /* Allocate a buffer without putting it in the buffer list. */
    newbuf = buflist_new(NULL, NULL, (linenr_T)1, BLN_DUMMY);
    if (newbuf == NULL)
	return NULL;

#ifdef FEAT_AUTOCMD
    /* set curwin/curbuf to buf and save a few things */
    aucmd_prepbuf(&aco, newbuf);
#else
    curbuf = newbuf;
    curwin->w_buffer = newbuf;
#endif

    /* Need to set the filename for autocommands. */
    (void)setfname(curbuf, fname, NULL, FALSE);

    if (ml_open() == OK)
    {
	/* Create swap file now to avoid the ATTENTION message. */
	check_need_swap(TRUE);

	/* Remove the "dummy" flag, otherwise autocommands may not
	 * work. */
	curbuf->b_flags &= ~BF_DUMMY;

	if (readfile(fname, NULL,
		    (linenr_T)0, (linenr_T)0, (linenr_T)MAXLNUM,
		    NULL, READ_NEW | READ_DUMMY) == OK
		&& !(curbuf->b_flags & BF_NEW))
	{
	    failed = FALSE;
	    if (curbuf != newbuf)
	    {
		/* Bloody autocommands changed the buffer! */
		if (buf_valid(newbuf))
		    wipe_buffer(newbuf, FALSE);
		newbuf = curbuf;
	    }
	}
    }

#ifdef FEAT_AUTOCMD
    /* restore curwin/curbuf and a few other things */
    aucmd_restbuf(&aco);
#else
    curbuf = old_curbuf;
    curwin->w_buffer = old_curbuf;
#endif

    if (!buf_valid(newbuf))
	return NULL;
    if (failed)
    {
	wipe_dummy_buffer(newbuf);
	return NULL;
    }
    return newbuf;
}

/*
 * Wipe out the dummy buffer that load_dummy_buffer() created.
 */
    static void
wipe_dummy_buffer(buf)
    buf_T	*buf;
{
    if (curbuf != buf)		/* safety check */
	wipe_buffer(buf, FALSE);
}

/*
 * Unload the dummy buffer that load_dummy_buffer() created.
 */
    static void
unload_dummy_buffer(buf)
    buf_T	*buf;
{
    if (curbuf != buf)		/* safety check */
	close_buffer(NULL, buf, DOBUF_UNLOAD);
}

/*
 * ":[range]cbuffer [bufnr]" command.
 */
    void
ex_cbuffer(eap)
    exarg_T   *eap;
{
    buf_T	*buf = NULL;

    if (*eap->arg == NUL)
	buf = curbuf;
    else if (*skipwhite(skipdigits(eap->arg)) == NUL)
	buf = buflist_findnr(atoi((char *)eap->arg));
    if (buf == NULL)
	EMSG(_(e_invarg));
    else if (buf->b_ml.ml_mfp == NULL)
	EMSG(_("E681: Buffer is not loaded"));
    else
    {
	if (eap->addr_count == 0)
	{
	    eap->line1 = 1;
	    eap->line2 = buf->b_ml.ml_line_count;
	}
	if (eap->line1 < 1 || eap->line1 > buf->b_ml.ml_line_count
		|| eap->line2 < 1 || eap->line2 > buf->b_ml.ml_line_count)
	    EMSG(_(e_invrange));
	else
	    qf_init_ext(NULL, buf, p_efm, TRUE, eap->line1, eap->line2);
    }
}

/*
 * ":helpgrep {pattern}"
 */
    void
ex_helpgrep(eap)
    exarg_T	*eap;
{
    regmatch_T	regmatch;
    char_u	*save_cpo;
    char_u	*p;
    int		fcount;
    char_u	**fnames;
    FILE	*fd;
    int		fi;
    struct qf_line *prevp = NULL;
    long	lnum;
#ifdef FEAT_MULTI_LANG
    char_u	*lang;
#endif

    /* Make 'cpoptions' empty, the 'l' flag should not be used here. */
    save_cpo = p_cpo;
    p_cpo = (char_u *)"";

#ifdef FEAT_MULTI_LANG
    /* Check for a specified language */
    lang = check_help_lang(eap->arg);
#endif

    regmatch.regprog = vim_regcomp(eap->arg, RE_MAGIC + RE_STRING);
    regmatch.rm_ic = FALSE;
    if (regmatch.regprog != NULL)
    {
	/* create a new quickfix list */
	qf_new_list();

	/* Go through all directories in 'runtimepath' */
	p = p_rtp;
	while (*p != NUL && !got_int)
	{
	    copy_option_part(&p, NameBuff, MAXPATHL, ",");

	    /* Find all "*.txt" and "*.??x" files in the "doc" directory. */
	    add_pathsep(NameBuff);
	    STRCAT(NameBuff, "doc/*.\\(txt\\|??x\\)");
	    if (gen_expand_wildcards(1, &NameBuff, &fcount,
					     &fnames, EW_FILE|EW_SILENT) == OK
		    && fcount > 0)
	    {
		for (fi = 0; fi < fcount && !got_int; ++fi)
		{
#ifdef FEAT_MULTI_LANG
		    /* Skip files for a different language. */
		    if (lang != NULL
			    && STRNICMP(lang, fnames[fi]
					    + STRLEN(fnames[fi]) - 3, 2) != 0
			    && !(STRNICMP(lang, "en", 2) == 0
				&& STRNICMP("txt", fnames[fi]
					   + STRLEN(fnames[fi]) - 3, 3) == 0))
			    continue;
#endif
		    fd = fopen((char *)fnames[fi], "r");
		    if (fd != NULL)
		    {
			lnum = 1;
			while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int)
			{
			    if (vim_regexec(&regmatch, IObuff, (colnr_T)0))
			    {
				int	l = STRLEN(IObuff);

				/* remove trailing CR, LF, spaces, etc. */
				while (l > 0 && IObuff[l - 1] <= ' ')
				     IObuff[--l] = NUL;

				if (qf_add_entry(&prevp,
					    NULL,	/* dir */
					    fnames[fi],
					    IObuff,
					    lnum,
					    (int)(regmatch.startp[0] - IObuff)
								+ 1, /* col */
					    FALSE,	/* virt_col */
					    0,		/* nr */
					    1,		/* type */
					    TRUE	/* valid */
					    ) == FAIL)
				{
				    got_int = TRUE;
				    break;
				}
			    }
			    ++lnum;
			    line_breakcheck();
			}
			fclose(fd);
		    }
		}
		FreeWild(fcount, fnames);
	    }
	}
	vim_free(regmatch.regprog);

	qf_lists[qf_curlist].qf_nonevalid = FALSE;
	qf_lists[qf_curlist].qf_ptr = qf_lists[qf_curlist].qf_start;
	qf_lists[qf_curlist].qf_index = 1;
    }

    p_cpo = save_cpo;

#ifdef FEAT_WINDOWS
    qf_update_buffer();
#endif

    /* Jump to first match. */
    if (qf_lists[qf_curlist].qf_count > 0)
	qf_jump(0, 0, FALSE);
    else
	EMSG2(_(e_nomatch2), eap->arg);
}

#endif /* FEAT_QUICKFIX */
