view src/findfile.c @ 34074:1629cc65d78d v9.1.0006

patch 9.1.0006: is*() and to*() function may be unsafe Commit: https://github.com/vim/vim/commit/184f71cc6868a240dc872ed2852542bbc1d43e28 Author: Keith Thompson <Keith.S.Thompson@gmail.com> Date: Thu Jan 4 21:19:04 2024 +0100 patch 9.1.0006: is*() and to*() function may be unsafe Problem: is*() and to*() function may be unsafe Solution: Add SAFE_* macros and start using those instead (Keith Thompson) Use SAFE_() macros for is*() and to*() functions The standard is*() and to*() functions declared in <ctype.h> have undefined behavior for negative arguments other than EOF. If plain char is signed, passing an unchecked value from argv for from user input to one of these functions has undefined behavior. Solution: Add SAFE_*() macros that cast the argument to unsigned char. Most implementations behave sanely for negative arguments, and most character values in practice are non-negative, but it's still best to avoid undefined behavior. The change from #13347 has been omitted, as this has already been separately fixed in commit ac709e2fc0db6d31abb7da96f743c40956b60c3a (v9.0.2054) fixes: #13332 closes: #13347 Signed-off-by: Keith Thompson <Keith.S.Thompson@gmail.com> Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Thu, 04 Jan 2024 21:30:04 +0100
parents def9fc5c92d1
children
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.
 */

/*
 * findfile.c: Search for files in directories listed in 'path'
 */

#include "vim.h"

/*
 * File searching functions for 'path', 'tags' and 'cdpath' options.
 * External visible functions:
 * vim_findfile_init()		creates/initialises the search context
 * vim_findfile_free_visited()	free list of visited files/dirs of search
 *				context
 * vim_findfile()		find a file in the search context
 * vim_findfile_cleanup()	cleanup/free search context created by
 *				vim_findfile_init()
 *
 * All static functions and variables start with 'ff_'
 *
 * In general it works like this:
 * First you create yourself a search context by calling vim_findfile_init().
 * It is possible to give a search context from a previous call to
 * vim_findfile_init(), so it can be reused. After this you call vim_findfile()
 * until you are satisfied with the result or it returns NULL. On every call it
 * returns the next file which matches the conditions given to
 * vim_findfile_init(). If it doesn't find a next file it returns NULL.
 *
 * It is possible to call vim_findfile_init() again to reinitialise your search
 * with some new parameters. Don't forget to pass your old search context to
 * it, so it can reuse it and especially reuse the list of already visited
 * directories. If you want to delete the list of already visited directories
 * simply call vim_findfile_free_visited().
 *
 * When you are done call vim_findfile_cleanup() to free the search context.
 *
 * The function vim_findfile_init() has a long comment, which describes the
 * needed parameters.
 *
 *
 *
 * ATTENTION:
 * ==========
 *	Also we use an allocated search context here, these functions are NOT
 *	thread-safe!
 *
 *	To minimize parameter passing (or because I'm to lazy), only the
 *	external visible functions get a search context as a parameter. This is
 *	then assigned to a static global, which is used throughout the local
 *	functions.
 */

/*
 * type for the directory search stack
 */
typedef struct ff_stack
{
    struct ff_stack	*ffs_prev;

    // the fix part (no wildcards) and the part containing the wildcards
    // of the search path
    char_u		*ffs_fix_path;
    char_u		*ffs_wc_path;

    // files/dirs found in the above directory, matched by the first wildcard
    // of wc_part
    char_u		**ffs_filearray;
    int			ffs_filearray_size;
    int			ffs_filearray_cur;   // needed for partly handled dirs

    // to store status of partly handled directories
    // 0: we work on this directory for the first time
    // 1: this directory was partly searched in an earlier step
    int			ffs_stage;

    // How deep are we in the directory tree?
    // Counts backward from value of level parameter to vim_findfile_init
    int			ffs_level;

    // Did we already expand '**' to an empty string?
    int			ffs_star_star_empty;
} ff_stack_T;

/*
 * type for already visited directories or files.
 */
typedef struct ff_visited
{
    struct ff_visited	*ffv_next;

    // Visited directories are different if the wildcard string are
    // different. So we have to save it.
    char_u		*ffv_wc_path;

    // for unix use inode etc for comparison (needed because of links), else
    // use filename.
#ifdef UNIX
    int			ffv_dev_valid;	// ffv_dev and ffv_ino were set
    dev_t		ffv_dev;	// device number
    ino_t		ffv_ino;	// inode number
#endif
    // The memory for this struct is allocated according to the length of
    // ffv_fname.
    char_u		ffv_fname[1];	// actually longer
} ff_visited_T;

/*
 * We might have to manage several visited lists during a search.
 * This is especially needed for the tags option. If tags is set to:
 *      "./++/tags,./++/TAGS,++/tags"  (replace + with *)
 * So we have to do 3 searches:
 *   1) search from the current files directory downward for the file "tags"
 *   2) search from the current files directory downward for the file "TAGS"
 *   3) search from Vims current directory downwards for the file "tags"
 * As you can see, the first and the third search are for the same file, so for
 * the third search we can use the visited list of the first search. For the
 * second search we must start from a empty visited list.
 * The struct ff_visited_list_hdr is used to manage a linked list of already
 * visited lists.
 */
typedef struct ff_visited_list_hdr
{
    struct ff_visited_list_hdr	*ffvl_next;

    // the filename the attached visited list is for
    char_u			*ffvl_filename;

    ff_visited_T		*ffvl_visited_list;

} ff_visited_list_hdr_T;


/*
 * '**' can be expanded to several directory levels.
 * Set the default maximum depth.
 */
#define FF_MAX_STAR_STAR_EXPAND ((char_u)30)

/*
 * The search context:
 *   ffsc_stack_ptr:	the stack for the dirs to search
 *   ffsc_visited_list: the currently active visited list
 *   ffsc_dir_visited_list: the currently active visited list for search dirs
 *   ffsc_visited_lists_list: the list of all visited lists
 *   ffsc_dir_visited_lists_list: the list of all visited lists for search dirs
 *   ffsc_file_to_search:     the file to search for
 *   ffsc_start_dir:	the starting directory, if search path was relative
 *   ffsc_fix_path:	the fix part of the given path (without wildcards)
 *			Needed for upward search.
 *   ffsc_wc_path:	the part of the given path containing wildcards
 *   ffsc_level:	how many levels of dirs to search downwards
 *   ffsc_stopdirs_v:	array of stop directories for upward search
 *   ffsc_find_what:	FINDFILE_BOTH, FINDFILE_DIR or FINDFILE_FILE
 *   ffsc_tagfile:	searching for tags file, don't use 'suffixesadd'
 */
typedef struct ff_search_ctx_T
{
     ff_stack_T			*ffsc_stack_ptr;
     ff_visited_list_hdr_T	*ffsc_visited_list;
     ff_visited_list_hdr_T	*ffsc_dir_visited_list;
     ff_visited_list_hdr_T	*ffsc_visited_lists_list;
     ff_visited_list_hdr_T	*ffsc_dir_visited_lists_list;
     char_u			*ffsc_file_to_search;
     char_u			*ffsc_start_dir;
     char_u			*ffsc_fix_path;
     char_u			*ffsc_wc_path;
     int			ffsc_level;
     char_u			**ffsc_stopdirs_v;
     int			ffsc_find_what;
     int			ffsc_tagfile;
} ff_search_ctx_T;

// locally needed functions
static int ff_check_visited(ff_visited_T **, char_u *, char_u *);
static void vim_findfile_free_visited(void *search_ctx_arg);
static void vim_findfile_free_visited_list(ff_visited_list_hdr_T **list_headp);
static void ff_free_visited_list(ff_visited_T *vl);
static ff_visited_list_hdr_T* ff_get_visited_list(char_u *, ff_visited_list_hdr_T **list_headp);

static void ff_push(ff_search_ctx_T *search_ctx, ff_stack_T *stack_ptr);
static ff_stack_T *ff_pop(ff_search_ctx_T *search_ctx);
static void ff_clear(ff_search_ctx_T *search_ctx);
static void ff_free_stack_element(ff_stack_T *stack_ptr);
static ff_stack_T *ff_create_stack_element(char_u *, char_u *, int, int);
static int ff_path_in_stoplist(char_u *, int, char_u **);

static char_u	*ff_expand_buffer = NULL; // used for expanding filenames

#if 0
/*
 * if someone likes findfirst/findnext, here are the functions
 * NOT TESTED!!
 */

static void *ff_fn_search_context = NULL;

    char_u *
vim_findfirst(char_u *path, char_u *filename, int level)
{
    ff_fn_search_context =
	vim_findfile_init(path, filename, NULL, level, TRUE, FALSE,
		ff_fn_search_context, rel_fname);
    if (NULL == ff_fn_search_context)
	return NULL;
    else
	return vim_findnext()
}

    char_u *
vim_findnext(void)
{
    char_u *ret = vim_findfile(ff_fn_search_context);

    if (NULL == ret)
    {
	vim_findfile_cleanup(ff_fn_search_context);
	ff_fn_search_context = NULL;
    }
    return ret;
}
#endif

/*
 * Initialization routine for vim_findfile().
 *
 * Returns the newly allocated search context or NULL if an error occurred.
 *
 * Don't forget to clean up by calling vim_findfile_cleanup() if you are done
 * with the search context.
 *
 * Find the file 'filename' in the directory 'path'.
 * The parameter 'path' may contain wildcards. If so only search 'level'
 * directories deep. The parameter 'level' is the absolute maximum and is
 * not related to restricts given to the '**' wildcard. If 'level' is 100
 * and you use '**200' vim_findfile() will stop after 100 levels.
 *
 * 'filename' cannot contain wildcards!  It is used as-is, no backslashes to
 * escape special characters.
 *
 * If 'stopdirs' is not NULL and nothing is found downward, the search is
 * restarted on the next higher directory level. This is repeated until the
 * start-directory of a search is contained in 'stopdirs'. 'stopdirs' has the
 * format ";*<dirname>*\(;<dirname>\)*;\=$".
 *
 * If the 'path' is relative, the starting dir for the search is either VIM's
 * current dir or if the path starts with "./" the current files dir.
 * If the 'path' is absolute, the starting dir is that part of the path before
 * the first wildcard.
 *
 * Upward search is only done on the starting dir.
 *
 * If 'free_visited' is TRUE the list of already visited files/directories is
 * cleared. Set this to FALSE if you just want to search from another
 * directory, but want to be sure that no directory from a previous search is
 * searched again. This is useful if you search for a file at different places.
 * The list of visited files/dirs can also be cleared with the function
 * vim_findfile_free_visited().
 *
 * Set the parameter 'find_what' to FINDFILE_DIR if you want to search for
 * directories only, FINDFILE_FILE for files only, FINDFILE_BOTH for both.
 *
 * A search context returned by a previous call to vim_findfile_init() can be
 * passed in the parameter "search_ctx_arg".  This context is reused and
 * reinitialized with the new parameters.  The list of already visited
 * directories from this context is only deleted if the parameter
 * "free_visited" is true.  Be aware that the passed "search_ctx_arg" is freed
 * if the reinitialization fails.
 *
 * If you don't have a search context from a previous call "search_ctx_arg"
 * must be NULL.
 *
 * This function silently ignores a few errors, vim_findfile() will have
 * limited functionality then.
 */
    void *
vim_findfile_init(
    char_u	*path,
    char_u	*filename,
    char_u	*stopdirs UNUSED,
    int		level,
    int		free_visited,
    int		find_what,
    void	*search_ctx_arg,
    int		tagfile,	// expanding names of tags files
    char_u	*rel_fname)	// file name to use for "."
{
    char_u		*wc_part;
    ff_stack_T		*sptr;
    ff_search_ctx_T	*search_ctx;

    // If a search context is given by the caller, reuse it, else allocate a
    // new one.
    if (search_ctx_arg != NULL)
	search_ctx = search_ctx_arg;
    else
    {
	search_ctx = ALLOC_CLEAR_ONE(ff_search_ctx_T);
	if (search_ctx == NULL)
	    goto error_return;
    }
    search_ctx->ffsc_find_what = find_what;
    search_ctx->ffsc_tagfile = tagfile;

    // clear the search context, but NOT the visited lists
    ff_clear(search_ctx);

    // clear visited list if wanted
    if (free_visited == TRUE)
	vim_findfile_free_visited(search_ctx);
    else
    {
	// Reuse old visited lists. Get the visited list for the given
	// filename. If no list for the current filename exists, creates a new
	// one.
	search_ctx->ffsc_visited_list = ff_get_visited_list(filename,
					&search_ctx->ffsc_visited_lists_list);
	if (search_ctx->ffsc_visited_list == NULL)
	    goto error_return;
	search_ctx->ffsc_dir_visited_list = ff_get_visited_list(filename,
				    &search_ctx->ffsc_dir_visited_lists_list);
	if (search_ctx->ffsc_dir_visited_list == NULL)
	    goto error_return;
    }

    if (ff_expand_buffer == NULL)
    {
	ff_expand_buffer = alloc(MAXPATHL);
	if (ff_expand_buffer == NULL)
	    goto error_return;
    }

    // Store information on starting dir now if path is relative.
    // If path is absolute, we do that later.
    if (path[0] == '.'
	    && (vim_ispathsep(path[1]) || path[1] == NUL)
	    && (!tagfile || vim_strchr(p_cpo, CPO_DOTTAG) == NULL)
	    && rel_fname != NULL)
    {
	int	len = (int)(gettail(rel_fname) - rel_fname);

	if (!vim_isAbsName(rel_fname) && len + 1 < MAXPATHL)
	{
	    // Make the start dir an absolute path name.
	    vim_strncpy(ff_expand_buffer, rel_fname, len);
	    search_ctx->ffsc_start_dir = FullName_save(ff_expand_buffer, FALSE);
	}
	else
	    search_ctx->ffsc_start_dir = vim_strnsave(rel_fname, len);
	if (search_ctx->ffsc_start_dir == NULL)
	    goto error_return;
	if (*++path != NUL)
	    ++path;
    }
    else if (*path == NUL || !vim_isAbsName(path))
    {
#ifdef BACKSLASH_IN_FILENAME
	// "c:dir" needs "c:" to be expanded, otherwise use current dir
	if (*path != NUL && path[1] == ':')
	{
	    char_u  drive[3];

	    drive[0] = path[0];
	    drive[1] = ':';
	    drive[2] = NUL;
	    if (vim_FullName(drive, ff_expand_buffer, MAXPATHL, TRUE) == FAIL)
		goto error_return;
	    path += 2;
	}
	else
#endif
	if (mch_dirname(ff_expand_buffer, MAXPATHL) == FAIL)
	    goto error_return;

	search_ctx->ffsc_start_dir = vim_strsave(ff_expand_buffer);
	if (search_ctx->ffsc_start_dir == NULL)
	    goto error_return;

#ifdef BACKSLASH_IN_FILENAME
	// A path that starts with "/dir" is relative to the drive, not to the
	// directory (but not for "//machine/dir").  Only use the drive name.
	if ((*path == '/' || *path == '\\')
		&& path[1] != path[0]
		&& search_ctx->ffsc_start_dir[1] == ':')
	    search_ctx->ffsc_start_dir[2] = NUL;
#endif
    }

    /*
     * If stopdirs are given, split them into an array of pointers.
     * If this fails (mem allocation), there is no upward search at all or a
     * stop directory is not recognized -> continue silently.
     * If stopdirs just contains a ";" or is empty,
     * search_ctx->ffsc_stopdirs_v will only contain a  NULL pointer. This
     * is handled as unlimited upward search.  See function
     * ff_path_in_stoplist() for details.
     */
    if (stopdirs != NULL)
    {
	char_u	*walker = stopdirs;
	int	dircount;

	while (*walker == ';')
	    walker++;

	dircount = 1;
	search_ctx->ffsc_stopdirs_v = ALLOC_ONE(char_u *);

	if (search_ctx->ffsc_stopdirs_v != NULL)
	{
	    do
	    {
		char_u	*helper;
		void	*ptr;

		helper = walker;
		ptr = vim_realloc(search_ctx->ffsc_stopdirs_v,
					   (dircount + 1) * sizeof(char_u *));
		if (ptr)
		    search_ctx->ffsc_stopdirs_v = ptr;
		else
		    // ignore, keep what we have and continue
		    break;
		walker = vim_strchr(walker, ';');
		if (walker)
		{
		    search_ctx->ffsc_stopdirs_v[dircount-1] =
					 vim_strnsave(helper, walker - helper);
		    walker++;
		}
		else
		    // this might be "", which means ascent till top
		    // of directory tree.
		    search_ctx->ffsc_stopdirs_v[dircount-1] =
							  vim_strsave(helper);

		dircount++;

	    } while (walker != NULL);
	    search_ctx->ffsc_stopdirs_v[dircount-1] = NULL;
	}
    }

    search_ctx->ffsc_level = level;

    /*
     * split into:
     *  -fix path
     *  -wildcard_stuff (might be NULL)
     */
    wc_part = vim_strchr(path, '*');
    if (wc_part != NULL)
    {
	int	llevel;
	int	len;
	char	*errpt;

	// save the fix part of the path
	search_ctx->ffsc_fix_path = vim_strnsave(path, wc_part - path);

	/*
	 * copy wc_path and add restricts to the '**' wildcard.
	 * The octet after a '**' is used as a (binary) counter.
	 * So '**3' is transposed to '**^C' ('^C' is ASCII value 3)
	 * or '**76' is transposed to '**N'( 'N' is ASCII value 76).
	 * If no restrict is given after '**' the default is used.
	 * Due to this technique the path looks awful if you print it as a
	 * string.
	 */
	len = 0;
	while (*wc_part != NUL)
	{
	    if (len + 5 >= MAXPATHL)
	    {
		emsg(_(e_path_too_long_for_completion));
		break;
	    }
	    if (STRNCMP(wc_part, "**", 2) == 0)
	    {
		ff_expand_buffer[len++] = *wc_part++;
		ff_expand_buffer[len++] = *wc_part++;

		llevel = strtol((char *)wc_part, &errpt, 10);
		if ((char_u *)errpt != wc_part && llevel > 0 && llevel < 255)
		    ff_expand_buffer[len++] = llevel;
		else if ((char_u *)errpt != wc_part && llevel == 0)
		    // restrict is 0 -> remove already added '**'
		    len -= 2;
		else
		    ff_expand_buffer[len++] = FF_MAX_STAR_STAR_EXPAND;
		wc_part = (char_u *)errpt;
		if (*wc_part != NUL && !vim_ispathsep(*wc_part))
		{
		    semsg(_(e_invalid_path_number_must_be_at_end_of_path_or_be_followed_by_str), PATHSEPSTR);
		    goto error_return;
		}
	    }
	    else
		ff_expand_buffer[len++] = *wc_part++;
	}
	ff_expand_buffer[len] = NUL;
	search_ctx->ffsc_wc_path = vim_strsave(ff_expand_buffer);

	if (search_ctx->ffsc_wc_path == NULL)
	    goto error_return;
    }
    else
	search_ctx->ffsc_fix_path = vim_strsave(path);

    if (search_ctx->ffsc_start_dir == NULL)
    {
	// store the fix part as startdir.
	// This is needed if the parameter path is fully qualified.
	search_ctx->ffsc_start_dir = vim_strsave(search_ctx->ffsc_fix_path);
	if (search_ctx->ffsc_start_dir == NULL)
	    goto error_return;
	search_ctx->ffsc_fix_path[0] = NUL;
    }

    // create an absolute path
    if (STRLEN(search_ctx->ffsc_start_dir)
			  + STRLEN(search_ctx->ffsc_fix_path) + 3 >= MAXPATHL)
    {
	emsg(_(e_path_too_long_for_completion));
	goto error_return;
    }
    STRCPY(ff_expand_buffer, search_ctx->ffsc_start_dir);
    add_pathsep(ff_expand_buffer);
    {
	int    eb_len = (int)STRLEN(ff_expand_buffer);
	char_u *buf = alloc(eb_len
				+ (int)STRLEN(search_ctx->ffsc_fix_path) + 1);

	STRCPY(buf, ff_expand_buffer);
	STRCPY(buf + eb_len, search_ctx->ffsc_fix_path);
	if (mch_isdir(buf))
	{
	    STRCAT(ff_expand_buffer, search_ctx->ffsc_fix_path);
	    add_pathsep(ff_expand_buffer);
	}
	else
	{
	    char_u *p =  gettail(search_ctx->ffsc_fix_path);
	    char_u *wc_path = NULL;
	    char_u *temp = NULL;
	    int    len = 0;

	    if (p > search_ctx->ffsc_fix_path)
	    {
		// do not add '..' to the path and start upwards searching
		len = (int)(p - search_ctx->ffsc_fix_path) - 1;
		if ((len >= 2
			&& STRNCMP(search_ctx->ffsc_fix_path, "..", 2) == 0)
			&& (len == 2
				   || search_ctx->ffsc_fix_path[2] == PATHSEP))
		{
		    vim_free(buf);
		    goto error_return;
		}
		STRNCAT(ff_expand_buffer, search_ctx->ffsc_fix_path, len);
		add_pathsep(ff_expand_buffer);
	    }
	    else
		len = (int)STRLEN(search_ctx->ffsc_fix_path);

	    if (search_ctx->ffsc_wc_path != NULL)
	    {
		wc_path = vim_strsave(search_ctx->ffsc_wc_path);
		temp = alloc(STRLEN(search_ctx->ffsc_wc_path)
				 + STRLEN(search_ctx->ffsc_fix_path + len)
				 + 1);
		if (temp == NULL || wc_path == NULL)
		{
		    vim_free(buf);
		    vim_free(temp);
		    vim_free(wc_path);
		    goto error_return;
		}

		STRCPY(temp, search_ctx->ffsc_fix_path + len);
		STRCAT(temp, search_ctx->ffsc_wc_path);
		vim_free(search_ctx->ffsc_wc_path);
		vim_free(wc_path);
		search_ctx->ffsc_wc_path = temp;
	    }
	}
	vim_free(buf);
    }

    sptr = ff_create_stack_element(ff_expand_buffer,
					   search_ctx->ffsc_wc_path, level, 0);

    if (sptr == NULL)
	goto error_return;

    ff_push(search_ctx, sptr);

    search_ctx->ffsc_file_to_search = vim_strsave(filename);
    if (search_ctx->ffsc_file_to_search == NULL)
	goto error_return;

    return search_ctx;

error_return:
    /*
     * We clear the search context now!
     * Even when the caller gave us a (perhaps valid) context we free it here,
     * as we might have already destroyed it.
     */
    vim_findfile_cleanup(search_ctx);
    return NULL;
}

/*
 * Get the stopdir string.  Check that ';' is not escaped.
 */
    char_u *
vim_findfile_stopdir(char_u *buf)
{
    char_u	*r_ptr = buf;

    while (*r_ptr != NUL && *r_ptr != ';')
    {
	if (r_ptr[0] == '\\' && r_ptr[1] == ';')
	{
	    // Overwrite the escape char,
	    // use STRLEN(r_ptr) to move the trailing '\0'.
	    STRMOVE(r_ptr, r_ptr + 1);
	    r_ptr++;
	}
	r_ptr++;
    }
    if (*r_ptr == ';')
    {
	*r_ptr = 0;
	r_ptr++;
    }
    else if (*r_ptr == NUL)
	r_ptr = NULL;
    return r_ptr;
}

/*
 * Clean up the given search context. Can handle a NULL pointer.
 */
    void
vim_findfile_cleanup(void *ctx)
{
    if (ctx == NULL)
	return;

    vim_findfile_free_visited(ctx);
    ff_clear(ctx);
    vim_free(ctx);
}

/*
 * Find a file in a search context.
 * The search context was created with vim_findfile_init() above.
 * Return a pointer to an allocated file name or NULL if nothing found.
 * To get all matching files call this function until you get NULL.
 *
 * If the passed search_context is NULL, NULL is returned.
 *
 * The search algorithm is depth first. To change this replace the
 * stack with a list (don't forget to leave partly searched directories on the
 * top of the list).
 */
    char_u *
vim_findfile(void *search_ctx_arg)
{
    char_u	*file_path;
    char_u	*rest_of_wildcards;
    char_u	*path_end = NULL;
    ff_stack_T	*stackp;
    int		len;
    int		i;
    char_u	*p;
    char_u	*suf;
    ff_search_ctx_T *search_ctx;

    if (search_ctx_arg == NULL)
	return NULL;

    search_ctx = (ff_search_ctx_T *)search_ctx_arg;

    /*
     * filepath is used as buffer for various actions and as the storage to
     * return a found filename.
     */
    if ((file_path = alloc(MAXPATHL)) == NULL)
	return NULL;

    // store the end of the start dir -- needed for upward search
    if (search_ctx->ffsc_start_dir != NULL)
	path_end = &search_ctx->ffsc_start_dir[
					  STRLEN(search_ctx->ffsc_start_dir)];

    // upward search loop
    for (;;)
    {
	// downward search loop
	for (;;)
	{
	    // check if user wants to stop the search
	    ui_breakcheck();
	    if (got_int)
		break;

	    // get directory to work on from stack
	    stackp = ff_pop(search_ctx);
	    if (stackp == NULL)
		break;

	    /*
	     * TODO: decide if we leave this test in
	     *
	     * GOOD: don't search a directory(-tree) twice.
	     * BAD:  - check linked list for every new directory entered.
	     *       - check for double files also done below
	     *
	     * Here we check if we already searched this directory.
	     * We already searched a directory if:
	     * 1) The directory is the same.
	     * 2) We would use the same wildcard string.
	     *
	     * Good if you have links on same directory via several ways
	     *  or you have selfreferences in directories (e.g. SuSE Linux 6.3:
	     *  /etc/rc.d/init.d is linked to /etc/rc.d -> endless loop)
	     *
	     * This check is only needed for directories we work on for the
	     * first time (hence stackp->ff_filearray == NULL)
	     */
	    if (stackp->ffs_filearray == NULL
		    && ff_check_visited(&search_ctx->ffsc_dir_visited_list
							  ->ffvl_visited_list,
			    stackp->ffs_fix_path, stackp->ffs_wc_path) == FAIL)
	    {
#ifdef FF_VERBOSE
		if (p_verbose >= 5)
		{
		    verbose_enter_scroll();
		    smsg("Already Searched: %s (%s)",
				   stackp->ffs_fix_path, stackp->ffs_wc_path);
		    // don't overwrite this either
		    msg_puts("\n");
		    verbose_leave_scroll();
		}
#endif
		ff_free_stack_element(stackp);
		continue;
	    }
#ifdef FF_VERBOSE
	    else if (p_verbose >= 5)
	    {
		verbose_enter_scroll();
		smsg("Searching: %s (%s)",
				   stackp->ffs_fix_path, stackp->ffs_wc_path);
		// don't overwrite this either
		msg_puts("\n");
		verbose_leave_scroll();
	    }
#endif

	    // check depth
	    if (stackp->ffs_level <= 0)
	    {
		ff_free_stack_element(stackp);
		continue;
	    }

	    file_path[0] = NUL;

	    /*
	     * If no filearray till now expand wildcards
	     * The function expand_wildcards() can handle an array of paths
	     * and all possible expands are returned in one array. We use this
	     * to handle the expansion of '**' into an empty string.
	     */
	    if (stackp->ffs_filearray == NULL)
	    {
		char_u *dirptrs[2];

		// we use filepath to build the path expand_wildcards() should
		// expand.
		dirptrs[0] = file_path;
		dirptrs[1] = NULL;

		// if we have a start dir copy it in
		if (!vim_isAbsName(stackp->ffs_fix_path)
						&& search_ctx->ffsc_start_dir)
		{
		    if (STRLEN(search_ctx->ffsc_start_dir) + 1 < MAXPATHL)
		    {
			STRCPY(file_path, search_ctx->ffsc_start_dir);
			add_pathsep(file_path);
		    }
		    else
		    {
			ff_free_stack_element(stackp);
			goto fail;
		    }
		}

		// append the fix part of the search path
		if (STRLEN(file_path) + STRLEN(stackp->ffs_fix_path) + 1
								    < MAXPATHL)
		{
		    STRCAT(file_path, stackp->ffs_fix_path);
		    add_pathsep(file_path);
		}
		else
		{
		    ff_free_stack_element(stackp);
		    goto fail;
		}

		rest_of_wildcards = stackp->ffs_wc_path;
		if (*rest_of_wildcards != NUL)
		{
		    len = (int)STRLEN(file_path);
		    if (STRNCMP(rest_of_wildcards, "**", 2) == 0)
		    {
			// pointer to the restrict byte
			// The restrict byte is not a character!
			p = rest_of_wildcards + 2;

			if (*p > 0)
			{
			    (*p)--;
			    if (len + 1 < MAXPATHL)
				file_path[len++] = '*';
			    else
			    {
				ff_free_stack_element(stackp);
				goto fail;
			    }
			}

			if (*p == 0)
			{
			    // remove '**<numb> from wildcards
			    STRMOVE(rest_of_wildcards, rest_of_wildcards + 3);
			}
			else
			    rest_of_wildcards += 3;

			if (stackp->ffs_star_star_empty == 0)
			{
			    // if not done before, expand '**' to empty
			    stackp->ffs_star_star_empty = 1;
			    dirptrs[1] = stackp->ffs_fix_path;
			}
		    }

		    /*
		     * Here we copy until the next path separator or the end of
		     * the path. If we stop at a path separator, there is
		     * still something else left. This is handled below by
		     * pushing every directory returned from expand_wildcards()
		     * on the stack again for further search.
		     */
		    while (*rest_of_wildcards
			    && !vim_ispathsep(*rest_of_wildcards))
			if (len + 1 < MAXPATHL)
			    file_path[len++] = *rest_of_wildcards++;
			else
			{
			    ff_free_stack_element(stackp);
			    goto fail;
			}

		    file_path[len] = NUL;
		    if (vim_ispathsep(*rest_of_wildcards))
			rest_of_wildcards++;
		}

		/*
		 * Expand wildcards like "*" and "$VAR".
		 * If the path is a URL don't try this.
		 */
		if (path_with_url(dirptrs[0]))
		{
		    stackp->ffs_filearray = ALLOC_ONE(char_u *);
		    if (stackp->ffs_filearray != NULL
			    && (stackp->ffs_filearray[0]
				= vim_strsave(dirptrs[0])) != NULL)
			stackp->ffs_filearray_size = 1;
		    else
			stackp->ffs_filearray_size = 0;
		}
		else
		    // Add EW_NOTWILD because the expanded path may contain
		    // wildcard characters that are to be taken literally.
		    // This is a bit of a hack.
		    expand_wildcards((dirptrs[1] == NULL) ? 1 : 2, dirptrs,
			    &stackp->ffs_filearray_size,
			    &stackp->ffs_filearray,
			    EW_DIR|EW_ADDSLASH|EW_SILENT|EW_NOTWILD);

		stackp->ffs_filearray_cur = 0;
		stackp->ffs_stage = 0;
	    }
	    else
		rest_of_wildcards = &stackp->ffs_wc_path[
						 STRLEN(stackp->ffs_wc_path)];

	    if (stackp->ffs_stage == 0)
	    {
		// this is the first time we work on this directory
		if (*rest_of_wildcards == NUL)
		{
		    /*
		     * We don't have further wildcards to expand, so we have to
		     * check for the final file now.
		     */
		    for (i = stackp->ffs_filearray_cur;
					  i < stackp->ffs_filearray_size; ++i)
		    {
			if (!path_with_url(stackp->ffs_filearray[i])
				      && !mch_isdir(stackp->ffs_filearray[i]))
			    continue;   // not a directory

			// prepare the filename to be checked for existence
			// below
			if (STRLEN(stackp->ffs_filearray[i]) + 1
				+ STRLEN(search_ctx->ffsc_file_to_search)
								    < MAXPATHL)
			{
			    STRCPY(file_path, stackp->ffs_filearray[i]);
			    add_pathsep(file_path);
			    STRCAT(file_path, search_ctx->ffsc_file_to_search);
			}
			else
			{
			    ff_free_stack_element(stackp);
			    goto fail;
			}

			/*
			 * Try without extra suffix and then with suffixes
			 * from 'suffixesadd'.
			 */
			len = (int)STRLEN(file_path);
			if (search_ctx->ffsc_tagfile)
			    suf = (char_u *)"";
			else
			    suf = curbuf->b_p_sua;
			for (;;)
			{
			    // if file exists and we didn't already find it
			    if ((path_with_url(file_path)
				  || (mch_getperm(file_path) >= 0
				      && (search_ctx->ffsc_find_what
							      == FINDFILE_BOTH
					  || ((search_ctx->ffsc_find_what
							      == FINDFILE_DIR)
						   == mch_isdir(file_path)))))
#ifndef FF_VERBOSE
				    && (ff_check_visited(
					    &search_ctx->ffsc_visited_list
							   ->ffvl_visited_list,
					    file_path, (char_u *)"") == OK)
#endif
			       )
			    {
#ifdef FF_VERBOSE
				if (ff_check_visited(
					    &search_ctx->ffsc_visited_list
							   ->ffvl_visited_list,
					      file_path, (char_u *)"") == FAIL)
				{
				    if (p_verbose >= 5)
				    {
					verbose_enter_scroll();
					smsg("Already: %s",
								   file_path);
					// don't overwrite this either
					msg_puts("\n");
					verbose_leave_scroll();
				    }
				    continue;
				}
#endif

				// push dir to examine rest of subdirs later
				stackp->ffs_filearray_cur = i + 1;
				ff_push(search_ctx, stackp);

				if (!path_with_url(file_path))
				    simplify_filename(file_path);
				if (mch_dirname(ff_expand_buffer, MAXPATHL)
									== OK)
				{
				    p = shorten_fname(file_path,
							    ff_expand_buffer);
				    if (p != NULL)
					STRMOVE(file_path, p);
				}
#ifdef FF_VERBOSE
				if (p_verbose >= 5)
				{
				    verbose_enter_scroll();
				    smsg("HIT: %s", file_path);
				    // don't overwrite this either
				    msg_puts("\n");
				    verbose_leave_scroll();
				}
#endif
				return file_path;
			    }

			    // Not found or found already, try next suffix.
			    if (*suf == NUL)
				break;
			    copy_option_part(&suf, file_path + len,
							 MAXPATHL - len, ",");
			}
		    }
		}
		else
		{
		    /*
		     * still wildcards left, push the directories for further
		     * search
		     */
		    for (i = stackp->ffs_filearray_cur;
					  i < stackp->ffs_filearray_size; ++i)
		    {
			if (!mch_isdir(stackp->ffs_filearray[i]))
			    continue;	// not a directory

			ff_push(search_ctx,
				ff_create_stack_element(
						     stackp->ffs_filearray[i],
						     rest_of_wildcards,
						     stackp->ffs_level - 1, 0));
		    }
		}
		stackp->ffs_filearray_cur = 0;
		stackp->ffs_stage = 1;
	    }

	    /*
	     * if wildcards contains '**' we have to descent till we reach the
	     * leaves of the directory tree.
	     */
	    if (STRNCMP(stackp->ffs_wc_path, "**", 2) == 0)
	    {
		for (i = stackp->ffs_filearray_cur;
					  i < stackp->ffs_filearray_size; ++i)
		{
		    if (fnamecmp(stackp->ffs_filearray[i],
						   stackp->ffs_fix_path) == 0)
			continue; // don't repush same directory
		    if (!mch_isdir(stackp->ffs_filearray[i]))
			continue;   // not a directory
		    ff_push(search_ctx,
			    ff_create_stack_element(stackp->ffs_filearray[i],
				stackp->ffs_wc_path, stackp->ffs_level - 1, 1));
		}
	    }

	    // we are done with the current directory
	    ff_free_stack_element(stackp);

	}

	// If we reached this, we didn't find anything downwards.
	// Let's check if we should do an upward search.
	if (search_ctx->ffsc_start_dir
		&& search_ctx->ffsc_stopdirs_v != NULL && !got_int)
	{
	    ff_stack_T  *sptr;

	    // is the last starting directory in the stop list?
	    if (ff_path_in_stoplist(search_ctx->ffsc_start_dir,
		       (int)(path_end - search_ctx->ffsc_start_dir),
		       search_ctx->ffsc_stopdirs_v) == TRUE)
		break;

	    // cut of last dir
	    while (path_end > search_ctx->ffsc_start_dir
						  && vim_ispathsep(*path_end))
		path_end--;
	    while (path_end > search_ctx->ffsc_start_dir
					      && !vim_ispathsep(path_end[-1]))
		path_end--;
	    *path_end = 0;
	    path_end--;

	    if (*search_ctx->ffsc_start_dir == 0)
		break;

	    if (STRLEN(search_ctx->ffsc_start_dir) + 1
		    + STRLEN(search_ctx->ffsc_fix_path) < MAXPATHL)
	    {
		STRCPY(file_path, search_ctx->ffsc_start_dir);
		add_pathsep(file_path);
		STRCAT(file_path, search_ctx->ffsc_fix_path);
	    }
	    else
		goto fail;

	    // create a new stack entry
	    sptr = ff_create_stack_element(file_path,
		    search_ctx->ffsc_wc_path, search_ctx->ffsc_level, 0);
	    if (sptr == NULL)
		break;
	    ff_push(search_ctx, sptr);
	}
	else
	    break;
    }

fail:
    vim_free(file_path);
    return NULL;
}

/*
 * Free the list of lists of visited files and directories
 * Can handle it if the passed search_context is NULL;
 */
    static void
vim_findfile_free_visited(void *search_ctx_arg)
{
    ff_search_ctx_T *search_ctx;

    if (search_ctx_arg == NULL)
	return;

    search_ctx = (ff_search_ctx_T *)search_ctx_arg;
    vim_findfile_free_visited_list(&search_ctx->ffsc_visited_lists_list);
    vim_findfile_free_visited_list(&search_ctx->ffsc_dir_visited_lists_list);
}

    static void
vim_findfile_free_visited_list(ff_visited_list_hdr_T **list_headp)
{
    ff_visited_list_hdr_T *vp;

    while (*list_headp != NULL)
    {
	vp = (*list_headp)->ffvl_next;
	ff_free_visited_list((*list_headp)->ffvl_visited_list);

	vim_free((*list_headp)->ffvl_filename);
	vim_free(*list_headp);
	*list_headp = vp;
    }
    *list_headp = NULL;
}

    static void
ff_free_visited_list(ff_visited_T *vl)
{
    ff_visited_T *vp;

    while (vl != NULL)
    {
	vp = vl->ffv_next;
	vim_free(vl->ffv_wc_path);
	vim_free(vl);
	vl = vp;
    }
    vl = NULL;
}

/*
 * Returns the already visited list for the given filename. If none is found it
 * allocates a new one.
 */
    static ff_visited_list_hdr_T*
ff_get_visited_list(
    char_u			*filename,
    ff_visited_list_hdr_T	**list_headp)
{
    ff_visited_list_hdr_T  *retptr = NULL;

    // check if a visited list for the given filename exists
    if (*list_headp != NULL)
    {
	retptr = *list_headp;
	while (retptr != NULL)
	{
	    if (fnamecmp(filename, retptr->ffvl_filename) == 0)
	    {
#ifdef FF_VERBOSE
		if (p_verbose >= 5)
		{
		    verbose_enter_scroll();
		    smsg("ff_get_visited_list: FOUND list for %s",
								    filename);
		    // don't overwrite this either
		    msg_puts("\n");
		    verbose_leave_scroll();
		}
#endif
		return retptr;
	    }
	    retptr = retptr->ffvl_next;
	}
    }

#ifdef FF_VERBOSE
    if (p_verbose >= 5)
    {
	verbose_enter_scroll();
	smsg("ff_get_visited_list: new list for %s", filename);
	// don't overwrite this either
	msg_puts("\n");
	verbose_leave_scroll();
    }
#endif

    /*
     * if we reach this we didn't find a list and we have to allocate new list
     */
    retptr = ALLOC_ONE(ff_visited_list_hdr_T);
    if (retptr == NULL)
	return NULL;

    retptr->ffvl_visited_list = NULL;
    retptr->ffvl_filename = vim_strsave(filename);
    if (retptr->ffvl_filename == NULL)
    {
	vim_free(retptr);
	return NULL;
    }
    retptr->ffvl_next = *list_headp;
    *list_headp = retptr;

    return retptr;
}

/*
 * check if two wildcard paths are equal. Returns TRUE or FALSE.
 * They are equal if:
 *  - both paths are NULL
 *  - they have the same length
 *  - char by char comparison is OK
 *  - the only differences are in the counters behind a '**', so
 *    '**\20' is equal to '**\24'
 */
    static int
ff_wc_equal(char_u *s1, char_u *s2)
{
    int		i, j;
    int		c1 = NUL;
    int		c2 = NUL;
    int		prev1 = NUL;
    int		prev2 = NUL;

    if (s1 == s2)
	return TRUE;

    if (s1 == NULL || s2 == NULL)
	return FALSE;

    for (i = 0, j = 0; s1[i] != NUL && s2[j] != NUL;)
    {
	c1 = PTR2CHAR(s1 + i);
	c2 = PTR2CHAR(s2 + j);

	if ((p_fic ? MB_TOLOWER(c1) != MB_TOLOWER(c2) : c1 != c2)
		&& (prev1 != '*' || prev2 != '*'))
	    return FALSE;
	prev2 = prev1;
	prev1 = c1;

	i += mb_ptr2len(s1 + i);
	j += mb_ptr2len(s2 + j);
    }
    return s1[i] == s2[j];
}

/*
 * maintains the list of already visited files and dirs
 * returns FAIL if the given file/dir is already in the list
 * returns OK if it is newly added
 *
 * TODO: What to do on memory allocation problems?
 *	 -> return TRUE - Better the file is found several times instead of
 *	    never.
 */
    static int
ff_check_visited(
    ff_visited_T	**visited_list,
    char_u		*fname,
    char_u		*wc_path)
{
    ff_visited_T	*vp;
#ifdef UNIX
    stat_T		st;
    int			url = FALSE;
#endif

    // For a URL we only compare the name, otherwise we compare the
    // device/inode (unix) or the full path name (not Unix).
    if (path_with_url(fname))
    {
	vim_strncpy(ff_expand_buffer, fname, MAXPATHL - 1);
#ifdef UNIX
	url = TRUE;
#endif
    }
    else
    {
	ff_expand_buffer[0] = NUL;
#ifdef UNIX
	if (mch_stat((char *)fname, &st) < 0)
#else
	if (vim_FullName(fname, ff_expand_buffer, MAXPATHL, TRUE) == FAIL)
#endif
	    return FAIL;
    }

    // check against list of already visited files
    for (vp = *visited_list; vp != NULL; vp = vp->ffv_next)
    {
	if (
#ifdef UNIX
		!url ? (vp->ffv_dev_valid && vp->ffv_dev == st.st_dev
						  && vp->ffv_ino == st.st_ino)
		     :
#endif
		fnamecmp(vp->ffv_fname, ff_expand_buffer) == 0
	   )
	{
	    // are the wildcard parts equal
	    if (ff_wc_equal(vp->ffv_wc_path, wc_path) == TRUE)
		// already visited
		return FAIL;
	}
    }

    /*
     * New file/dir.  Add it to the list of visited files/dirs.
     */
    vp = alloc(
	     offsetof(ff_visited_T, ffv_fname) + STRLEN(ff_expand_buffer) + 1);
    if (vp == NULL)
	return OK;

#ifdef UNIX
    if (!url)
    {
	vp->ffv_dev_valid = TRUE;
	vp->ffv_ino = st.st_ino;
	vp->ffv_dev = st.st_dev;
	vp->ffv_fname[0] = NUL;
    }
    else
    {
	vp->ffv_dev_valid = FALSE;
#endif
	STRCPY(vp->ffv_fname, ff_expand_buffer);
#ifdef UNIX
    }
#endif
    if (wc_path != NULL)
	vp->ffv_wc_path = vim_strsave(wc_path);
    else
	vp->ffv_wc_path = NULL;

    vp->ffv_next = *visited_list;
    *visited_list = vp;

    return OK;
}

/*
 * create stack element from given path pieces
 */
    static ff_stack_T *
ff_create_stack_element(
    char_u	*fix_part,
    char_u	*wc_part,
    int		level,
    int		star_star_empty)
{
    ff_stack_T	*new;

    new = ALLOC_ONE(ff_stack_T);
    if (new == NULL)
	return NULL;

    new->ffs_prev	   = NULL;
    new->ffs_filearray	   = NULL;
    new->ffs_filearray_size = 0;
    new->ffs_filearray_cur  = 0;
    new->ffs_stage	   = 0;
    new->ffs_level	   = level;
    new->ffs_star_star_empty = star_star_empty;

    // the following saves NULL pointer checks in vim_findfile
    if (fix_part == NULL)
	fix_part = (char_u *)"";
    new->ffs_fix_path = vim_strsave(fix_part);

    if (wc_part == NULL)
	wc_part  = (char_u *)"";
    new->ffs_wc_path = vim_strsave(wc_part);

    if (new->ffs_fix_path == NULL || new->ffs_wc_path == NULL)
    {
	ff_free_stack_element(new);
	new = NULL;
    }

    return new;
}

/*
 * Push a dir on the directory stack.
 */
    static void
ff_push(ff_search_ctx_T *search_ctx, ff_stack_T *stack_ptr)
{
    // check for NULL pointer, not to return an error to the user, but
    // to prevent a crash
    if (stack_ptr == NULL)
	return;

    stack_ptr->ffs_prev = search_ctx->ffsc_stack_ptr;
    search_ctx->ffsc_stack_ptr = stack_ptr;
}

/*
 * Pop a dir from the directory stack.
 * Returns NULL if stack is empty.
 */
    static ff_stack_T *
ff_pop(ff_search_ctx_T *search_ctx)
{
    ff_stack_T  *sptr;

    sptr = search_ctx->ffsc_stack_ptr;
    if (search_ctx->ffsc_stack_ptr != NULL)
	search_ctx->ffsc_stack_ptr = search_ctx->ffsc_stack_ptr->ffs_prev;

    return sptr;
}

/*
 * free the given stack element
 */
    static void
ff_free_stack_element(ff_stack_T *stack_ptr)
{
    // vim_free handles possible NULL pointers
    vim_free(stack_ptr->ffs_fix_path);
    vim_free(stack_ptr->ffs_wc_path);

    if (stack_ptr->ffs_filearray != NULL)
	FreeWild(stack_ptr->ffs_filearray_size, stack_ptr->ffs_filearray);

    vim_free(stack_ptr);
}

/*
 * Clear the search context, but NOT the visited list.
 */
    static void
ff_clear(ff_search_ctx_T *search_ctx)
{
    ff_stack_T   *sptr;

    // clear up stack
    while ((sptr = ff_pop(search_ctx)) != NULL)
	ff_free_stack_element(sptr);

    vim_free(search_ctx->ffsc_file_to_search);
    vim_free(search_ctx->ffsc_start_dir);
    vim_free(search_ctx->ffsc_fix_path);
    vim_free(search_ctx->ffsc_wc_path);

    if (search_ctx->ffsc_stopdirs_v != NULL)
    {
	int  i = 0;

	while (search_ctx->ffsc_stopdirs_v[i] != NULL)
	{
	    vim_free(search_ctx->ffsc_stopdirs_v[i]);
	    i++;
	}
	vim_free(search_ctx->ffsc_stopdirs_v);
    }
    search_ctx->ffsc_stopdirs_v = NULL;

    // reset everything
    search_ctx->ffsc_file_to_search = NULL;
    search_ctx->ffsc_start_dir = NULL;
    search_ctx->ffsc_fix_path = NULL;
    search_ctx->ffsc_wc_path = NULL;
    search_ctx->ffsc_level = 0;
}

/*
 * check if the given path is in the stopdirs
 * returns TRUE if yes else FALSE
 */
    static int
ff_path_in_stoplist(char_u *path, int path_len, char_u **stopdirs_v)
{
    int		i = 0;

    // eat up trailing path separators, except the first
    while (path_len > 1 && vim_ispathsep(path[path_len - 1]))
	path_len--;

    // if no path consider it as match
    if (path_len == 0)
	return TRUE;

    for (i = 0; stopdirs_v[i] != NULL; i++)
    {
	if ((int)STRLEN(stopdirs_v[i]) > path_len)
	{
	    // match for parent directory. So '/home' also matches
	    // '/home/rks'. Check for PATHSEP in stopdirs_v[i], else
	    // '/home/r' would also match '/home/rks'
	    if (fnamencmp(stopdirs_v[i], path, path_len) == 0
		    && vim_ispathsep(stopdirs_v[i][path_len]))
		return TRUE;
	}
	else
	{
	    if (fnamecmp(stopdirs_v[i], path) == 0)
		return TRUE;
	}
    }
    return FALSE;
}

/*
 * Find the file name "ptr[len]" in the path.  Also finds directory names.
 *
 * On the first call set the parameter 'first' to TRUE to initialize
 * the search.  For repeating calls to FALSE.
 *
 * Repeating calls will return other files called 'ptr[len]' from the path.
 *
 * Only on the first call 'ptr' and 'len' are used.  For repeating calls they
 * don't need valid values.
 *
 * If nothing found on the first call the option FNAME_MESS will issue the
 * message:
 *	    'Can't find file "<file>" in path'
 * On repeating calls:
 *	    'No more file "<file>" found in path'
 *
 * options:
 * FNAME_MESS	    give error message when not found
 *
 * Uses NameBuff[]!
 *
 * Returns an allocated string for the file name.  NULL for error.
 *
 */
    char_u *
find_file_in_path(
    char_u	*ptr,		// file name
    int		len,		// length of file name
    int		options,
    int		first,		// use count'th matching file name
    char_u	*rel_fname,	// file name searching relative to
    char_u	**file_to_find,	// in/out: modified copy of file name
    char	**search_ctx)	// in/out: state of the search
{
    return find_file_in_path_option(ptr, len, options, first,
	    *curbuf->b_p_path == NUL ? p_path : curbuf->b_p_path,
	    FINDFILE_BOTH, rel_fname, curbuf->b_p_sua,
	    file_to_find, search_ctx);
}

# if defined(EXITFREE) || defined(PROTO)
    void
free_findfile(void)
{
    VIM_CLEAR(ff_expand_buffer);
}
# endif

/*
 * Find the directory name "ptr[len]" in the path.
 *
 * options:
 * FNAME_MESS	    give error message when not found
 * FNAME_UNESC	    unescape backslashes.
 *
 * Uses NameBuff[]!
 *
 * Returns an allocated string for the file name.  NULL for error.
 */
    char_u *
find_directory_in_path(
    char_u	*ptr,		// file name
    int		len,		// length of file name
    int		options,
    char_u	*rel_fname,	// file name searching relative to
    char_u	**file_to_find,	// in/out: modified copy of file name
    char	**search_ctx)	// in/out: state of the search
{
    return find_file_in_path_option(ptr, len, options, TRUE, p_cdpath,
				       FINDFILE_DIR, rel_fname, (char_u *)"",
				       file_to_find, search_ctx);
}

    char_u *
find_file_in_path_option(
    char_u	*ptr,		// file name
    int		len,		// length of file name
    int		options,
    int		first,		// use count'th matching file name
    char_u	*path_option,	// p_path or p_cdpath
    int		find_what,	// FINDFILE_FILE, _DIR or _BOTH
    char_u	*rel_fname,	// file name we are looking relative to.
    char_u	*suffixes,	// list of suffixes, 'suffixesadd' option
    char_u	**file_to_find,	// in/out: modified copy of file name
    char	**search_ctx_arg) // in/out: state of the search
{
    ff_search_ctx_T	**search_ctx = (ff_search_ctx_T **)search_ctx_arg;
    static char_u	*dir;
    static int		did_findfile_init = FALSE;
    char_u		save_char;
    char_u		*file_name = NULL;
    char_u		*buf = NULL;
    int			rel_to_curdir;
# ifdef AMIGA
    struct Process	*proc = (struct Process *)FindTask(0L);
    APTR		save_winptr = proc->pr_WindowPtr;

    // Avoid a requester here for a volume that doesn't exist.
    proc->pr_WindowPtr = (APTR)-1L;
# endif

    if (first == TRUE)
    {
	if (len == 0)
	    return NULL;

	// copy file name into NameBuff, expanding environment variables
	save_char = ptr[len];
	ptr[len] = NUL;
	expand_env_esc(ptr, NameBuff, MAXPATHL, FALSE, TRUE, NULL);
	ptr[len] = save_char;

	vim_free(*file_to_find);
	*file_to_find = vim_strsave(NameBuff);
	if (*file_to_find == NULL)	// out of memory
	{
	    file_name = NULL;
	    goto theend;
	}
	if (options & FNAME_UNESC)
	{
	    // Change all "\ " to " ".
	    for (ptr = *file_to_find; *ptr != NUL; ++ptr)
		if (ptr[0] == '\\' && ptr[1] == ' ')
		    mch_memmove(ptr, ptr + 1, STRLEN(ptr));
	}
    }

    rel_to_curdir = ((*file_to_find)[0] == '.'
		    && ((*file_to_find)[1] == NUL
			|| vim_ispathsep((*file_to_find)[1])
			|| ((*file_to_find)[1] == '.'
			    && ((*file_to_find)[2] == NUL
				|| vim_ispathsep((*file_to_find)[2])))));
    if (vim_isAbsName(*file_to_find)
	    // "..", "../path", "." and "./path": don't use the path_option
	    || rel_to_curdir
# if defined(MSWIN)
	    // handle "\tmp" as absolute path
	    || vim_ispathsep((*file_to_find)[0])
	    // handle "c:name" as absolute path
	    || ((*file_to_find)[0] != NUL && (*file_to_find)[1] == ':')
# endif
# ifdef AMIGA
	    // handle ":tmp" as absolute path
	    || (*file_to_find)[0] == ':'
# endif
       )
    {
	/*
	 * Absolute path, no need to use "path_option".
	 * If this is not a first call, return NULL.  We already returned a
	 * filename on the first call.
	 */
	if (first == TRUE)
	{
	    int		l;
	    int		run;

	    if (path_with_url(*file_to_find))
	    {
		file_name = vim_strsave(*file_to_find);
		goto theend;
	    }

	    // When FNAME_REL flag given first use the directory of the file.
	    // Otherwise or when this fails use the current directory.
	    for (run = 1; run <= 2; ++run)
	    {
		l = (int)STRLEN(*file_to_find);
		if (run == 1
			&& rel_to_curdir
			&& (options & FNAME_REL)
			&& rel_fname != NULL
			&& STRLEN(rel_fname) + l < MAXPATHL)
		{
		    STRCPY(NameBuff, rel_fname);
		    STRCPY(gettail(NameBuff), *file_to_find);
		    l = (int)STRLEN(NameBuff);
		}
		else
		{
		    STRCPY(NameBuff, *file_to_find);
		    run = 2;
		}

		// When the file doesn't exist, try adding parts of
		// 'suffixesadd'.
		buf = suffixes;
		for (;;)
		{
		    if (mch_getperm(NameBuff) >= 0
			     && (find_what == FINDFILE_BOTH
				 || ((find_what == FINDFILE_DIR)
						    == mch_isdir(NameBuff))))
		    {
			file_name = vim_strsave(NameBuff);
			goto theend;
		    }
		    if (*buf == NUL)
			break;
		    copy_option_part(&buf, NameBuff + l, MAXPATHL - l, ",");
		}
	    }
	}
    }
    else
    {
	/*
	 * Loop over all paths in the 'path' or 'cdpath' option.
	 * When "first" is set, first setup to the start of the option.
	 * Otherwise continue to find the next match.
	 */
	if (first == TRUE)
	{
	    // vim_findfile_free_visited can handle a possible NULL pointer
	    vim_findfile_free_visited(*search_ctx);
	    dir = path_option;
	    did_findfile_init = FALSE;
	}

	for (;;)
	{
	    if (did_findfile_init)
	    {
		file_name = vim_findfile(*search_ctx);
		if (file_name != NULL)
		    break;

		did_findfile_init = FALSE;
	    }
	    else
	    {
		char_u  *r_ptr;

		if (dir == NULL || *dir == NUL)
		{
		    // We searched all paths of the option, now we can
		    // free the search context.
		    vim_findfile_cleanup(*search_ctx);
		    *search_ctx = NULL;
		    break;
		}

		if ((buf = alloc(MAXPATHL)) == NULL)
		    break;

		// copy next path
		buf[0] = 0;
		copy_option_part(&dir, buf, MAXPATHL, " ,");

		// get the stopdir string
		r_ptr = vim_findfile_stopdir(buf);
		*search_ctx = vim_findfile_init(buf, *file_to_find,
					    r_ptr, 100, FALSE, find_what,
					   *search_ctx, FALSE, rel_fname);
		if (*search_ctx != NULL)
		    did_findfile_init = TRUE;
		vim_free(buf);
	    }
	}
    }
    if (file_name == NULL && (options & FNAME_MESS))
    {
	if (first == TRUE)
	{
	    if (find_what == FINDFILE_DIR)
		semsg(_(e_cant_find_directory_str_in_cdpath), *file_to_find);
	    else
		semsg(_(e_cant_find_file_str_in_path), *file_to_find);
	}
	else
	{
	    if (find_what == FINDFILE_DIR)
		semsg(_(e_no_more_directory_str_found_in_cdpath),
								*file_to_find);
	    else
		semsg(_(e_no_more_file_str_found_in_path), *file_to_find);
	}
    }

theend:
# ifdef AMIGA
    proc->pr_WindowPtr = save_winptr;
# endif
    return file_name;
}

/*
 * Get the file name at the cursor.
 * If Visual mode is active, use the selected text if it's in one line.
 * Returns the name in allocated memory, NULL for failure.
 */
    char_u *
grab_file_name(long count, linenr_T *file_lnum)
{
    int options = FNAME_MESS|FNAME_EXP|FNAME_REL|FNAME_UNESC;

    if (VIsual_active)
    {
	int	len;
	char_u	*ptr;

	if (get_visual_text(NULL, &ptr, &len) == FAIL)
	    return NULL;
	// Only recognize ":123" here
	if (file_lnum != NULL && ptr[len] == ':' && SAFE_isdigit(ptr[len + 1]))
	{
	    char_u *p = ptr + len + 1;

	    *file_lnum = getdigits(&p);
	}
	return find_file_name_in_path(ptr, len, options,
						     count, curbuf->b_ffname);
    }
    return file_name_at_cursor(options | FNAME_HYP, count, file_lnum);
}

/*
 * Return the file name under or after the cursor.
 *
 * The 'path' option is searched if the file name is not absolute.
 * The string returned has been alloc'ed and should be freed by the caller.
 * NULL is returned if the file name or file is not found.
 *
 * options:
 * FNAME_MESS	    give error messages
 * FNAME_EXP	    expand to path
 * FNAME_HYP	    check for hypertext link
 * FNAME_INCL	    apply "includeexpr"
 */
    char_u *
file_name_at_cursor(int options, long count, linenr_T *file_lnum)
{
    return file_name_in_line(ml_get_curline(),
		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
		      file_lnum);
}

/*
 * Return the name of the file under or after ptr[col].
 * Otherwise like file_name_at_cursor().
 */
    char_u *
file_name_in_line(
    char_u	*line,
    int		col,
    int		options,
    long	count,
    char_u	*rel_fname,	// file we are searching relative to
    linenr_T	*file_lnum)	// line number after the file name
{
    char_u	*ptr;
    int		len;
    int		in_type = TRUE;
    int		is_url = FALSE;

    /*
     * search forward for what could be the start of a file name
     */
    ptr = line + col;
    while (*ptr != NUL && !vim_isfilec(*ptr))
	MB_PTR_ADV(ptr);
    if (*ptr == NUL)		// nothing found
    {
	if (options & FNAME_MESS)
	    emsg(_(e_no_file_name_under_cursor));
	return NULL;
    }

    /*
     * Search backward for first char of the file name.
     * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
     */
    while (ptr > line)
    {
	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
	    ptr -= len + 1;
	else if (vim_isfilec(ptr[-1])
		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
	    --ptr;
	else
	    break;
    }

    /*
     * Search forward for the last char of the file name.
     * Also allow "://" when ':' is not in 'isfname'.
     */
    len = 0;
    while (vim_isfilec(ptr[len]) || (ptr[len] == '\\' && ptr[len + 1] == ' ')
		 || ((options & FNAME_HYP) && path_is_url(ptr + len))
		 || (is_url && vim_strchr((char_u *)":?&=", ptr[len]) != NULL))
    {
	// After type:// we also include :, ?, & and = as valid characters, so
	// that http://google.com:8080?q=this&that=ok works.
	if ((ptr[len] >= 'A' && ptr[len] <= 'Z')
				       || (ptr[len] >= 'a' && ptr[len] <= 'z'))
	{
	    if (in_type && path_is_url(ptr + len + 1))
		is_url = TRUE;
	}
	else
	    in_type = FALSE;

	if (ptr[len] == '\\')
	    // Skip over the "\" in "\ ".
	    ++len;
	if (has_mbyte)
	    len += (*mb_ptr2len)(ptr + len);
	else
	    ++len;
    }

    /*
     * If there is trailing punctuation, remove it.
     * But don't remove "..", could be a directory name.
     */
    if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
						       && ptr[len - 2] != '.')
	--len;

    if (file_lnum != NULL)
    {
	char_u *p;
	char	*line_english = " line ";
	char	*line_transl = _(line_msg);

	// Get the number after the file name and a separator character.
	// Also accept " line 999" with and without the same translation as
	// used in last_set_msg().
	p = ptr + len;
	if (STRNCMP(p, line_english, STRLEN(line_english)) == 0)
	    p += STRLEN(line_english);
	else if (STRNCMP(p, line_transl, STRLEN(line_transl)) == 0)
	    p += STRLEN(line_transl);
	else
	    p = skipwhite(p);
	if (*p != NUL)
	{
	    if (!SAFE_isdigit(*p))
		++p;		    // skip the separator
	    p = skipwhite(p);
	    if (SAFE_isdigit(*p))
		*file_lnum = (int)getdigits(&p);
	}
    }

    return find_file_name_in_path(ptr, len, options, count, rel_fname);
}

# if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
    static char_u *
eval_includeexpr(char_u *ptr, int len)
{
    char_u	*res;
    sctx_T	save_sctx = current_sctx;

    set_vim_var_string(VV_FNAME, ptr, len);
    current_sctx = curbuf->b_p_script_ctx[BV_INEX];

    res = eval_to_string_safe(curbuf->b_p_inex,
	    was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL),
								   TRUE, TRUE);

    set_vim_var_string(VV_FNAME, NULL, 0);
    current_sctx = save_sctx;
    return res;
}
# endif

/*
 * Return the name of the file ptr[len] in 'path'.
 * Otherwise like file_name_at_cursor().
 */
    char_u *
find_file_name_in_path(
    char_u	*ptr,
    int		len,
    int		options,
    long	count,
    char_u	*rel_fname)	// file we are searching relative to
{
    char_u	*file_name;
    int		c;
# if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
    char_u	*tofree = NULL;
# endif

    if (len == 0)
	return NULL;

# if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
    if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
    {
	tofree = eval_includeexpr(ptr, len);
	if (tofree != NULL)
	{
	    ptr = tofree;
	    len = (int)STRLEN(ptr);
	}
    }
# endif

    if (options & FNAME_EXP)
    {
	char_u	*file_to_find = NULL;
	char	*search_ctx = NULL;

	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
				  TRUE, rel_fname, &file_to_find, &search_ctx);

# if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
	/*
	 * If the file could not be found in a normal way, try applying
	 * 'includeexpr' (unless done already).
	 */
	if (file_name == NULL
		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
	{
	    tofree = eval_includeexpr(ptr, len);
	    if (tofree != NULL)
	    {
		ptr = tofree;
		len = (int)STRLEN(ptr);
		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
				  TRUE, rel_fname, &file_to_find, &search_ctx);
	    }
	}
# endif
	if (file_name == NULL && (options & FNAME_MESS))
	{
	    c = ptr[len];
	    ptr[len] = NUL;
	    semsg(_(e_cant_find_file_str_in_path_2), ptr);
	    ptr[len] = c;
	}

	// Repeat finding the file "count" times.  This matters when it
	// appears several times in the path.
	while (file_name != NULL && --count > 0)
	{
	    vim_free(file_name);
	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname,
						   &file_to_find, &search_ctx);
	}

	vim_free(file_to_find);
	vim_findfile_cleanup(search_ctx);
    }
    else
	file_name = vim_strnsave(ptr, len);

# if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
    vim_free(tofree);
# endif

    return file_name;
}

/*
 * Return the end of the directory name, on the first path
 * separator:
 * "/path/file", "/path/dir/", "/path//dir", "/file"
 *	 ^	       ^	     ^	      ^
 */
    static char_u *
gettail_dir(char_u *fname)
{
    char_u	*dir_end = fname;
    char_u	*next_dir_end = fname;
    int		look_for_sep = TRUE;
    char_u	*p;

    for (p = fname; *p != NUL; )
    {
	if (vim_ispathsep(*p))
	{
	    if (look_for_sep)
	    {
		next_dir_end = p;
		look_for_sep = FALSE;
	    }
	}
	else
	{
	    if (!look_for_sep)
		dir_end = next_dir_end;
	    look_for_sep = TRUE;
	}
	MB_PTR_ADV(p);
    }
    return dir_end;
}

/*
 * return TRUE if 'c' is a path list separator.
 */
    int
vim_ispathlistsep(int c)
{
# ifdef UNIX
    return (c == ':');
# else
    return (c == ';');	// might not be right for every system...
# endif
}

/*
 * Moves "*psep" back to the previous path separator in "path".
 * Returns FAIL is "*psep" ends up at the beginning of "path".
 */
    static int
find_previous_pathsep(char_u *path, char_u **psep)
{
    // skip the current separator
    if (*psep > path && vim_ispathsep(**psep))
	--*psep;

    // find the previous separator
    while (*psep > path)
    {
	if (vim_ispathsep(**psep))
	    return OK;
	MB_PTR_BACK(path, *psep);
    }

    return FAIL;
}

/*
 * Returns TRUE if "maybe_unique" is unique wrt other_paths in "gap".
 * "maybe_unique" is the end portion of "((char_u **)gap->ga_data)[i]".
 */
    static int
is_unique(char_u *maybe_unique, garray_T *gap, int i)
{
    int	    j;
    int	    candidate_len;
    int	    other_path_len;
    char_u  **other_paths = (char_u **)gap->ga_data;
    char_u  *rival;

    for (j = 0; j < gap->ga_len; j++)
    {
	if (j == i)
	    continue;  // don't compare it with itself

	candidate_len = (int)STRLEN(maybe_unique);
	other_path_len = (int)STRLEN(other_paths[j]);
	if (other_path_len < candidate_len)
	    continue;  // it's different when it's shorter

	rival = other_paths[j] + other_path_len - candidate_len;
	if (fnamecmp(maybe_unique, rival) == 0
		&& (rival == other_paths[j] || vim_ispathsep(*(rival - 1))))
	    return FALSE;  // match
    }

    return TRUE;  // no match found
}

/*
 * Split the 'path' option into an array of strings in garray_T.  Relative
 * paths are expanded to their equivalent fullpath.  This includes the "."
 * (relative to current buffer directory) and empty path (relative to current
 * directory) notations.
 *
 * TODO: handle upward search (;) and path limiter (**N) notations by
 * expanding each into their equivalent path(s).
 */
    static void
expand_path_option(char_u *curdir, garray_T *gap)
{
    char_u	*path_option = *curbuf->b_p_path == NUL
						  ? p_path : curbuf->b_p_path;
    char_u	*buf;
    char_u	*p;
    int		len;

    if ((buf = alloc(MAXPATHL)) == NULL)
	return;

    while (*path_option != NUL)
    {
	copy_option_part(&path_option, buf, MAXPATHL, " ,");

	if (buf[0] == '.' && (buf[1] == NUL || vim_ispathsep(buf[1])))
	{
	    // Relative to current buffer:
	    // "/path/file" + "." -> "/path/"
	    // "/path/file"  + "./subdir" -> "/path/subdir"
	    if (curbuf->b_ffname == NULL)
		continue;
	    p = gettail(curbuf->b_ffname);
	    len = (int)(p - curbuf->b_ffname);
	    if (len + (int)STRLEN(buf) >= MAXPATHL)
		continue;
	    if (buf[1] == NUL)
		buf[len] = NUL;
	    else
		STRMOVE(buf + len, buf + 2);
	    mch_memmove(buf, curbuf->b_ffname, len);
	    simplify_filename(buf);
	}
	else if (buf[0] == NUL)
	    // relative to current directory
	    STRCPY(buf, curdir);
	else if (path_with_url(buf))
	    // URL can't be used here
	    continue;
	else if (!mch_isFullName(buf))
	{
	    // Expand relative path to their full path equivalent
	    len = (int)STRLEN(curdir);
	    if (len + (int)STRLEN(buf) + 3 > MAXPATHL)
		continue;
	    STRMOVE(buf + len + 1, buf);
	    STRCPY(buf, curdir);
	    buf[len] = PATHSEP;
	    simplify_filename(buf);
	}

	if (ga_grow(gap, 1) == FAIL)
	    break;

# if defined(MSWIN)
	// Avoid the path ending in a backslash, it fails when a comma is
	// appended.
	len = (int)STRLEN(buf);
	if (buf[len - 1] == '\\')
	    buf[len - 1] = '/';
# endif

	p = vim_strsave(buf);
	if (p == NULL)
	    break;
	((char_u **)gap->ga_data)[gap->ga_len++] = p;
    }

    vim_free(buf);
}

/*
 * Returns a pointer to the file or directory name in "fname" that matches the
 * longest path in "ga"p, or NULL if there is no match. For example:
 *
 *    path: /foo/bar/baz
 *   fname: /foo/bar/baz/quux.txt
 * returns:		 ^this
 */
    static char_u *
get_path_cutoff(char_u *fname, garray_T *gap)
{
    int	    i;
    int	    maxlen = 0;
    char_u  **path_part = (char_u **)gap->ga_data;
    char_u  *cutoff = NULL;

    for (i = 0; i < gap->ga_len; i++)
    {
	int j = 0;

	while ((fname[j] == path_part[i][j]
# if defined(MSWIN)
		|| (vim_ispathsep(fname[j]) && vim_ispathsep(path_part[i][j]))
# endif
			     ) && fname[j] != NUL && path_part[i][j] != NUL)
	    j++;
	if (j > maxlen)
	{
	    maxlen = j;
	    cutoff = &fname[j];
	}
    }

    // skip to the file or directory name
    if (cutoff != NULL)
	while (vim_ispathsep(*cutoff))
	    MB_PTR_ADV(cutoff);

    return cutoff;
}

/*
 * Sorts, removes duplicates and modifies all the fullpath names in "gap" so
 * that they are unique with respect to each other while conserving the part
 * that matches the pattern. Beware, this is at least O(n^2) wrt "gap->ga_len".
 */
    void
uniquefy_paths(garray_T *gap, char_u *pattern)
{
    int		i;
    int		len;
    char_u	**fnames = (char_u **)gap->ga_data;
    int		sort_again = FALSE;
    char_u	*pat;
    char_u      *file_pattern;
    char_u	*curdir;
    regmatch_T	regmatch;
    garray_T	path_ga;
    char_u	**in_curdir = NULL;
    char_u	*short_name;

    remove_duplicates(gap);
    ga_init2(&path_ga, sizeof(char_u *), 1);

    /*
     * We need to prepend a '*' at the beginning of file_pattern so that the
     * regex matches anywhere in the path. FIXME: is this valid for all
     * possible patterns?
     */
    len = (int)STRLEN(pattern);
    file_pattern = alloc(len + 2);
    if (file_pattern == NULL)
	return;
    file_pattern[0] = '*';
    file_pattern[1] = NUL;
    STRCAT(file_pattern, pattern);
    pat = file_pat_to_reg_pat(file_pattern, NULL, NULL, TRUE);
    vim_free(file_pattern);
    if (pat == NULL)
	return;

    regmatch.rm_ic = TRUE;		// always ignore case
    regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
    vim_free(pat);
    if (regmatch.regprog == NULL)
	return;

    if ((curdir = alloc(MAXPATHL)) == NULL)
	goto theend;
    mch_dirname(curdir, MAXPATHL);
    expand_path_option(curdir, &path_ga);

    in_curdir = ALLOC_CLEAR_MULT(char_u *, gap->ga_len);
    if (in_curdir == NULL)
	goto theend;

    for (i = 0; i < gap->ga_len && !got_int; i++)
    {
	char_u	    *path = fnames[i];
	int	    is_in_curdir;
	char_u	    *dir_end = gettail_dir(path);
	char_u	    *pathsep_p;
	char_u	    *path_cutoff;

	len = (int)STRLEN(path);
	is_in_curdir = fnamencmp(curdir, path, dir_end - path) == 0
					     && curdir[dir_end - path] == NUL;
	if (is_in_curdir)
	    in_curdir[i] = vim_strsave(path);

	// Shorten the filename while maintaining its uniqueness
	path_cutoff = get_path_cutoff(path, &path_ga);

	// Don't assume all files can be reached without path when search
	// pattern starts with star star slash, so only remove path_cutoff
	// when possible.
	if (pattern[0] == '*' && pattern[1] == '*'
		&& vim_ispathsep_nocolon(pattern[2])
		&& path_cutoff != NULL
		&& vim_regexec(&regmatch, path_cutoff, (colnr_T)0)
		&& is_unique(path_cutoff, gap, i))
	{
	    sort_again = TRUE;
	    mch_memmove(path, path_cutoff, STRLEN(path_cutoff) + 1);
	}
	else
	{
	    // Here all files can be reached without path, so get shortest
	    // unique path.  We start at the end of the path.
	    pathsep_p = path + len - 1;

	    while (find_previous_pathsep(path, &pathsep_p))
		if (vim_regexec(&regmatch, pathsep_p + 1, (colnr_T)0)
			&& is_unique(pathsep_p + 1, gap, i)
			&& path_cutoff != NULL && pathsep_p + 1 >= path_cutoff)
		{
		    sort_again = TRUE;
		    mch_memmove(path, pathsep_p + 1, STRLEN(pathsep_p));
		    break;
		}
	}

	if (mch_isFullName(path))
	{
	    /*
	     * Last resort: shorten relative to curdir if possible.
	     * 'possible' means:
	     * 1. It is under the current directory.
	     * 2. The result is actually shorter than the original.
	     *
	     *	    Before		  curdir	After
	     *	    /foo/bar/file.txt	  /foo/bar	./file.txt
	     *	    c:\foo\bar\file.txt   c:\foo\bar	.\file.txt
	     *	    /file.txt		  /		/file.txt
	     *	    c:\file.txt		  c:\		.\file.txt
	     */
	    short_name = shorten_fname(path, curdir);
	    if (short_name != NULL && short_name > path + 1
# if defined(MSWIN)
		    // On windows,
		    //	    shorten_fname("c:\a\a.txt", "c:\a\b")
		    // returns "\a\a.txt", which is not really the short
		    // name, hence:
		    && !vim_ispathsep(*short_name)
# endif
		)
	    {
		STRCPY(path, ".");
		add_pathsep(path);
		STRMOVE(path + STRLEN(path), short_name);
	    }
	}
	ui_breakcheck();
    }

    // Shorten filenames in /in/current/directory/{filename}
    for (i = 0; i < gap->ga_len && !got_int; i++)
    {
	char_u *rel_path;
	char_u *path = in_curdir[i];

	if (path == NULL)
	    continue;

	// If the {filename} is not unique, change it to ./{filename}.
	// Else reduce it to {filename}
	short_name = shorten_fname(path, curdir);
	if (short_name == NULL)
	    short_name = path;
	if (is_unique(short_name, gap, i))
	{
	    STRCPY(fnames[i], short_name);
	    continue;
	}

	rel_path = alloc(STRLEN(short_name) + STRLEN(PATHSEPSTR) + 2);
	if (rel_path == NULL)
	    goto theend;
	STRCPY(rel_path, ".");
	add_pathsep(rel_path);
	STRCAT(rel_path, short_name);

	vim_free(fnames[i]);
	fnames[i] = rel_path;
	sort_again = TRUE;
	ui_breakcheck();
    }

theend:
    vim_free(curdir);
    if (in_curdir != NULL)
    {
	for (i = 0; i < gap->ga_len; i++)
	    vim_free(in_curdir[i]);
	vim_free(in_curdir);
    }
    ga_clear_strings(&path_ga);
    vim_regfree(regmatch.regprog);

    if (sort_again)
	remove_duplicates(gap);
}

/*
 * Calls globpath() with 'path' values for the given pattern and stores the
 * result in "gap".
 * Returns the total number of matches.
 */
    int
expand_in_path(
    garray_T	*gap,
    char_u	*pattern,
    int		flags)		// EW_* flags
{
    char_u	*curdir;
    garray_T	path_ga;
    char_u	*paths = NULL;
    int		glob_flags = 0;

    if ((curdir = alloc(MAXPATHL)) == NULL)
	return 0;
    mch_dirname(curdir, MAXPATHL);

    ga_init2(&path_ga, sizeof(char_u *), 1);
    expand_path_option(curdir, &path_ga);
    vim_free(curdir);
    if (path_ga.ga_len == 0)
	return 0;

    paths = ga_concat_strings(&path_ga, ",");
    ga_clear_strings(&path_ga);
    if (paths == NULL)
	return 0;

    if (flags & EW_ICASE)
	glob_flags |= WILD_ICASE;
    if (flags & EW_ADDSLASH)
	glob_flags |= WILD_ADD_SLASH;
    globpath(paths, pattern, gap, glob_flags, FALSE);
    vim_free(paths);

    return gap->ga_len;
}


/*
 * Converts a file name into a canonical form. It simplifies a file name into
 * its simplest form by stripping out unneeded components, if any.  The
 * resulting file name is simplified in place and will either be the same
 * length as that supplied, or shorter.
 */
    void
simplify_filename(char_u *filename)
{
#ifndef AMIGA	    // Amiga doesn't have "..", it uses "/"
    int		components = 0;
    char_u	*p, *tail, *start;
    int		stripping_disabled = FALSE;
    int		relative = TRUE;

    p = filename;
# ifdef BACKSLASH_IN_FILENAME
    if (p[0] != NUL && p[1] == ':')	    // skip "x:"
	p += 2;
# endif

    if (vim_ispathsep(*p))
    {
	relative = FALSE;
	do
	    ++p;
	while (vim_ispathsep(*p));
    }
    start = p;	    // remember start after "c:/" or "/" or "///"
#ifdef UNIX
    // Posix says that "//path" is unchanged but "///path" is "/path".
    if (start > filename + 2)
    {
	STRMOVE(filename + 1, p);
	start = p = filename + 1;
    }
#endif

    do
    {
	// At this point "p" is pointing to the char following a single "/"
	// or "p" is at the "start" of the (absolute or relative) path name.
# ifdef VMS
	// VMS allows device:[path] - don't strip the [ in directory
	if ((*p == '[' || *p == '<') && p > filename && p[-1] == ':')
	{
	    // :[ or :< composition: vms directory component
	    ++components;
	    p = getnextcomp(p + 1);
	}
	// allow remote calls as host"user passwd"::device:[path]
	else if (p[0] == ':' && p[1] == ':' && p > filename && p[-1] == '"' )
	{
	    // ":: composition: vms host/passwd component
	    ++components;
	    p = getnextcomp(p + 2);
	}
	else
# endif
	  if (vim_ispathsep(*p))
	    STRMOVE(p, p + 1);		// remove duplicate "/"
	else if (p[0] == '.' && (vim_ispathsep(p[1]) || p[1] == NUL))
	{
	    if (p == start && relative)
		p += 1 + (p[1] != NUL);	// keep single "." or leading "./"
	    else
	    {
		// Strip "./" or ".///".  If we are at the end of the file name
		// and there is no trailing path separator, either strip "/." if
		// we are after "start", or strip "." if we are at the beginning
		// of an absolute path name .
		tail = p + 1;
		if (p[1] != NUL)
		    while (vim_ispathsep(*tail))
			MB_PTR_ADV(tail);
		else if (p > start)
		    --p;		// strip preceding path separator
		STRMOVE(p, tail);
	    }
	}
	else if (p[0] == '.' && p[1] == '.' &&
	    (vim_ispathsep(p[2]) || p[2] == NUL))
	{
	    // Skip to after ".." or "../" or "..///".
	    tail = p + 2;
	    while (vim_ispathsep(*tail))
		MB_PTR_ADV(tail);

	    if (components > 0)		// strip one preceding component
	    {
		int		do_strip = FALSE;
		char_u		saved_char;
		stat_T		st;

		// Don't strip for an erroneous file name.
		if (!stripping_disabled)
		{
		    // If the preceding component does not exist in the file
		    // system, we strip it.  On Unix, we don't accept a symbolic
		    // link that refers to a non-existent file.
		    saved_char = p[-1];
		    p[-1] = NUL;
# ifdef UNIX
		    if (mch_lstat((char *)filename, &st) < 0)
# else
			if (mch_stat((char *)filename, &st) < 0)
# endif
			    do_strip = TRUE;
		    p[-1] = saved_char;

		    --p;
		    // Skip back to after previous '/'.
		    while (p > start && !after_pathsep(start, p))
			MB_PTR_BACK(start, p);

		    if (!do_strip)
		    {
			// If the component exists in the file system, check
			// that stripping it won't change the meaning of the
			// file name.  First get information about the
			// unstripped file name.  This may fail if the component
			// to strip is not a searchable directory (but a regular
			// file, for instance), since the trailing "/.." cannot
			// be applied then.  We don't strip it then since we
			// don't want to replace an erroneous file name by
			// a valid one, and we disable stripping of later
			// components.
			saved_char = *tail;
			*tail = NUL;
			if (mch_stat((char *)filename, &st) >= 0)
			    do_strip = TRUE;
			else
			    stripping_disabled = TRUE;
			*tail = saved_char;
# ifdef UNIX
			if (do_strip)
			{
			    stat_T	new_st;

			    // On Unix, the check for the unstripped file name
			    // above works also for a symbolic link pointing to
			    // a searchable directory.  But then the parent of
			    // the directory pointed to by the link must be the
			    // same as the stripped file name.  (The latter
			    // exists in the file system since it is the
			    // component's parent directory.)
			    if (p == start && relative)
				(void)mch_stat(".", &new_st);
			    else
			    {
				saved_char = *p;
				*p = NUL;
				(void)mch_stat((char *)filename, &new_st);
				*p = saved_char;
			    }

			    if (new_st.st_ino != st.st_ino ||
				new_st.st_dev != st.st_dev)
			    {
				do_strip = FALSE;
				// We don't disable stripping of later
				// components since the unstripped path name is
				// still valid.
			    }
			}
# endif
		    }
		}

		if (!do_strip)
		{
		    // Skip the ".." or "../" and reset the counter for the
		    // components that might be stripped later on.
		    p = tail;
		    components = 0;
		}
		else
		{
		    // Strip previous component.  If the result would get empty
		    // and there is no trailing path separator, leave a single
		    // "." instead.  If we are at the end of the file name and
		    // there is no trailing path separator and a preceding
		    // component is left after stripping, strip its trailing
		    // path separator as well.
		    if (p == start && relative && tail[-1] == '.')
		    {
			*p++ = '.';
			*p = NUL;
		    }
		    else
		    {
			if (p > start && tail[-1] == '.')
			    --p;
			STRMOVE(p, tail);	// strip previous component
		    }

		    --components;
		}
	    }
	    else if (p == start && !relative)	// leading "/.." or "/../"
		STRMOVE(p, tail);		// strip ".." or "../"
	    else
	    {
		if (p == start + 2 && p[-2] == '.')	// leading "./../"
		{
		    STRMOVE(p - 2, p);			// strip leading "./"
		    tail -= 2;
		}
		p = tail;		// skip to char after ".." or "../"
	    }
	}
	else
	{
	    ++components;		// simple path component
	    p = getnextcomp(p);
	}
    } while (*p != NUL);
#endif // !AMIGA
}

#if defined(FEAT_EVAL) || defined(PROTO)
/*
 * "simplify()" function
 */
    void
f_simplify(typval_T *argvars, typval_T *rettv)
{
    char_u	*p;

    if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
	return;

    p = tv_get_string_strict(&argvars[0]);
    rettv->vval.v_string = vim_strsave(p);
    simplify_filename(rettv->vval.v_string);	// simplify in place
    rettv->v_type = VAR_STRING;
}
#endif // FEAT_EVAL