mu/src/mu-maildir.c

/* -*-mode: c; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-*/

/* 
** Copyright (C) 2008-2011 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** This program is free software; you can redistribute it and/or modify it
** under the terms of the GNU General Public License as published by the
** Free Software Foundation; either version 3, or (at your option) any
** later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software Foundation,
** Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  
**  
*/

#if HAVE_CONFIG_H
#include "config.h"
#endif /*HAVE_CONFIG_H*/

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

/* hopefully, the should get us a sane PATH_MAX */
#include <limits.h>
/* not all systems provide PATH_MAX in limits.h */
#ifndef PATH_MAX
#include <sys/param.h>
#ifndef PATH_MAX
#define PATH_MAX MAXPATHLEN
#endif 	/*!PATH_MAX */
#endif 	/*PATH_MAX */

#include <string.h>
#include <errno.h>
#include <glib/gprintf.h>

#include "mu-util.h"
#include "mu-maildir.h"
#include "mu-str.h"

#define MU_MAILDIR_NOINDEX_FILE       ".noindex"

/* On Linux (and some BSD), we have entry->d_type, but some file
 * systems (XFS, ReiserFS) do not support it, and set it DT_UNKNOWN.
 * On other OSs, notably Solaris, entry->d_type is not present at all.
 * For these cases, we use lstat (in get_dtype) as a slower fallback,
 * and return it in the d_type parameter
 */
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
#define GET_DTYPE(DE,FP)						\
	((DE)->d_type == DT_UNKNOWN ? mu_util_get_dtype_with_lstat((FP)) : (DE)->d_type)
#else
#define GET_DTYPE(DE,FP)			\
	mu_util_get_dtype_with_lstat((FP))
#endif /*HAVE_STRUCT_DIRENT_D_TYPE*/


static gboolean
create_maildir (const char *path, mode_t mode, GError **err)
{
	int i;
	const gchar* subdirs[] = {"new", "cur", "tmp"};

	/* make sure it does not exist yet */
	if (access (path, F_OK) == 0)
		errno = EEXIST;

	if (errno != ENOENT) {
		g_set_error (err, 0, MU_ERROR_FILE, "%s", strerror (errno));
		return FALSE;
	}
	
	for (i = 0; i != G_N_ELEMENTS(subdirs); ++i) {

		const char *fullpath;
		int rv;

		/* static buffer */
		fullpath = mu_str_fullpath_s (path, subdirs[i]);
		rv = g_mkdir_with_parents (fullpath, (int)mode);
		if (rv != 0) {
			g_set_error (err, 0, MU_ERROR_FILE_CANNOT_MKDIR,
				     "g_mkdir_with_parents failed: %s",
				     strerror (errno));
			return FALSE;
		}
	}
	
	return TRUE;
}

static gboolean
create_noindex (const char *path, GError **err)
{	
	/* create a noindex file if requested */
	int fd;
	const char *noindexpath;

	/* static buffer */
	noindexpath = mu_str_fullpath_s (path, MU_MAILDIR_NOINDEX_FILE);

	fd = creat (noindexpath, 0644);
	
	/* note, if the 'close' failed, creation may still have
	 * succeeded...*/
	if (fd < 0 || close (fd) != 0) {
		g_set_error (err, 0, MU_ERROR_FILE_CANNOT_CREATE,
			     "error in create_noindex: %s",
			     strerror (errno));
		return FALSE;
	}
	
	return TRUE;
}

gboolean
mu_maildir_mkdir (const char* path, mode_t mode, gboolean noindex, GError **err)
{	
	g_return_val_if_fail (path, FALSE);
	
	MU_WRITE_LOG ("%s (%s, %o, %s)", __FUNCTION__,
		      path, mode, noindex ? "TRUE" : "FALSE");
	
	if (!create_maildir (path, mode, err))
		return FALSE;

	if (noindex && !create_noindex (path, err))
		return FALSE;
	
	return TRUE;
}

/* determine whether the source message is in 'new' or in 'cur';
 * we ignore messages in 'tmp' for obvious reasons */
static gboolean
check_subdir (const char *src, gboolean *in_cur, GError **err)
{
	gchar *srcpath;

	srcpath = g_path_get_dirname (src);

	if (g_str_has_suffix (srcpath, "new"))
		*in_cur = FALSE;
	else if (g_str_has_suffix (srcpath, "cur"))
		*in_cur = TRUE;
	else {
		g_set_error(err, 0, MU_ERROR_FILE_INVALID_SOURCE,
			    "invalid source message '%s'", src);
		return FALSE;
	}
	g_free (srcpath);
	
	return TRUE;
}

static gchar*
get_target_fullpath (const char* src, const gchar *targetpath, GError **err)
{
	gchar *targetfullpath, *srcfile;
	gboolean in_cur;
	
	if (!check_subdir (src, &in_cur, err))
		return NULL;
	
	srcfile = g_path_get_basename (src);

	/* create targetpath; note: make the filename cough* unique by
	 *including a hash * of the srcname in the targetname. This
	 *helps if there are * copies of a message (which all have the
	 *same basename)*/
	targetfullpath = g_strdup_printf ("%s%c%s%c%u_%s",
					  targetpath,
					  G_DIR_SEPARATOR,
					  in_cur ? "cur" : "new",
					  G_DIR_SEPARATOR,
					  g_str_hash(src),
					  srcfile);
	g_free (srcfile);
	
	return targetfullpath;
}


gboolean
mu_maildir_link (const char* src, const char *targetpath, GError **err)
{
	gchar *targetfullpath;
	int rv;
	
	g_return_val_if_fail (src, FALSE);
	g_return_val_if_fail (targetpath, FALSE);
	
	targetfullpath = get_target_fullpath (src, targetpath, err);
	if (!targetfullpath)
		return FALSE;
	
	rv = symlink (src, targetfullpath);
	
	if (rv != 0) {
		g_set_error (err, 0, MU_ERROR_FILE_CANNOT_LINK,
			     "error creating link %s => %s: %s",
			     targetfullpath, src, strerror (errno));
		g_free (targetfullpath);
		return FALSE;
	}

	g_free (targetfullpath);
	return TRUE;
}


static MuResult process_dir (const char* path, const gchar *mdir,
			     MuMaildirWalkMsgCallback msg_cb, 
			     MuMaildirWalkDirCallback dir_cb, void *data);

static MuResult 
process_file (const char* fullpath, const gchar* mdir,
	      MuMaildirWalkMsgCallback msg_cb, void *data)
{
	MuResult result;
	struct stat statbuf;
	
	if (!msg_cb)
		return MU_OK;

	if (G_UNLIKELY(access(fullpath, R_OK) != 0)) {
		g_warning ("cannot access %s: %s", fullpath,
			   strerror(errno));
		return MU_ERROR;
	}
	
	if (G_UNLIKELY(stat (fullpath, &statbuf) != 0)) {
		g_warning ("cannot stat %s: %s", fullpath, strerror(errno));
		return MU_ERROR;
	}
	
	result = (msg_cb)(fullpath, mdir, &statbuf, data);
	if (result == MU_STOP) 
		g_debug ("callback said 'MU_STOP' for %s", fullpath);
	else if (result == MU_ERROR)
		g_warning ("%s: error in callback (%s)",  
			   __FUNCTION__, fullpath);

	return result;
}


/*
 * determine if path is a maildir leaf-dir; ie. if it's 'cur' or 'new'
 * (we're skipping 'tmp' for obvious reasons)
 */
G_GNUC_CONST static gboolean 
is_maildir_new_or_cur (const char *path)
{
	size_t len;

	g_return_val_if_fail (path, FALSE);
	
	/* path is the full path; it cannot possibly be shorter
	 * than 4 for a maildir (/cur or /new) */
	len = strlen (path);
	if (G_UNLIKELY(len < 4))
		return FALSE;
	
	/* optimization; one further idea would be cast the 4 bytes to an integer
	 * and compare that -- need to think about alignment, endianness */
	
	if (path[len - 4] == G_DIR_SEPARATOR &&	
	    path[len - 3] == 'c' &&
	    path[len - 2] == 'u' &&
	    path[len - 1] == 'r')
		return TRUE;

	if (path[len - 4] == G_DIR_SEPARATOR &&	
	    path[len - 3] == 'n' &&
	    path[len - 2] == 'e' &&
	    path[len - 1] == 'w')
		return TRUE;

	return FALSE;
}

/* check if there is a noindex file (MU_MAILDIR_NOINDEX_FILE) in this
 * dir; */
static gboolean
has_noindex_file (const char *path)
{
	const char* noindexpath;

	/* static buffer */
	noindexpath = mu_str_fullpath_s (path, MU_MAILDIR_NOINDEX_FILE);

	if (access (noindexpath, F_OK) == 0)
		return TRUE;
	else if (G_UNLIKELY(errno != ENOENT))
		g_warning ("error testing for noindex file %s: %s",
			   noindexpath, strerror(errno));
	
	return FALSE;
}


static gboolean
is_dotdir_to_ignore (const char* dir)
{
	int i;
	const char* ignore[] = {
		".notmuch",
		".nnmaildir",
		".#evolution"
	}; /* when adding names, check the optimization below */
	
	if (dir[0] != '.')
		return FALSE; /* not a dotdir */

	if (dir[1] == '\0' || (dir[1] == '.' && dir[2] == '\0'))
		return TRUE; /* ignore '.' and '..' */

	/* optimization: special dirs have 'n' or '#' in pos 1 */
	if (dir[1] != 'n' && dir[1] != '#')
		return FALSE; /* not special: don't ignore */

	for (i = 0; i != G_N_ELEMENTS(ignore); ++i)
		if (strcmp(dir, ignore[i]) == 0)
			return TRUE;

	return FALSE; /* don't ignore */
}

static gboolean
ignore_dir_entry (struct dirent *entry, unsigned char d_type)
{
	const char *name;
	
	/* if it's not a dir and not a file, ignore it.
	 * note, this means also symlinks (DT_LNK) are ignored,
	 * maybe make this optional */
	if (G_UNLIKELY(d_type != DT_REG && d_type != DT_DIR))
		return TRUE;
	
	name = entry->d_name;
	
	/* ignore '.' and '..' dirs, as well as .notmuch and
	 * .nnmaildir */

	return is_dotdir_to_ignore (entry->d_name);
}


static gchar*
get_mdir_for_path (const gchar *old_mdir, const gchar *dir)
{
	if (dir[0] != 'n' && dir[0] != 'c' &&
	    strcmp(dir, "cur") != 0 && strcmp(dir, "new") != 0)
		return g_strconcat (old_mdir ? old_mdir : "",
				    G_DIR_SEPARATOR_S, dir, NULL);
	else
		return strdup (old_mdir ? old_mdir : G_DIR_SEPARATOR_S);
}


static MuResult
process_dir_entry (const char* path, const char* mdir, struct dirent *entry,
		   MuMaildirWalkMsgCallback cb_msg,
		   MuMaildirWalkDirCallback cb_dir, 
		   void *data)
{
	const char *fp;
	char* fullpath;
	unsigned char d_type;
	
	/* we have to copy the buffer from fullpath_s, because it
	 * returns a static buffer, and we maybe called reentrantly */
	fp = mu_str_fullpath_s (path, entry->d_name);
	fullpath = g_newa (char, strlen(fp) + 1);
	strcpy (fullpath, fp);

	d_type = GET_DTYPE(entry, fullpath);
	
	/* ignore special files/dirs */
	if (ignore_dir_entry (entry, d_type)) 
		return MU_OK;
	
	switch (d_type) {
	case DT_REG: /* we only want files in cur/ and new/ */
		if (!is_maildir_new_or_cur (path)) 
			return MU_OK;
		
		return process_file (fullpath, mdir, cb_msg, data);
		
	case DT_DIR: {
		char *my_mdir;
		MuResult rv;

		my_mdir = get_mdir_for_path (mdir, entry->d_name);
		rv = process_dir (fullpath, my_mdir, cb_msg, cb_dir, data);
		g_free (my_mdir);

		return rv;
	}
		
	default:
		return MU_OK; /* ignore other types */
	}
}


static struct dirent* 
dirent_copy (struct dirent *entry)
{
	struct dirent *d;

	d = g_slice_new (struct dirent);

	/* NOTE: simply memcpy'ing sizeof(struct dirent) bytes will
	 * give memory errors. */
	return (struct dirent*) memcpy (d, entry, entry->d_reclen);
}

static void
dirent_destroy (struct dirent *entry)
{
	g_slice_free (struct dirent, entry);
}

#ifdef HAVE_STRUCT_DIRENT_D_INO	
static int
dirent_cmp (struct dirent *d1, struct dirent *d2)
{
	/* we do it his way instead of a simple d1->d_ino - d2->d_ino
	 * because this way, we don't need 64-bit numbers for the
	 * actual sorting */
	if (d1->d_ino < d2->d_ino)
		return -1;
	else if (d1->d_ino > d2->d_ino)
		return 1;
	else
		return 0;
}
#endif /*HAVE_STRUCT_DIRENT_D_INO*/

static MuResult
process_dir_entries (DIR *dir, const char* path, const char* mdir,
		     MuMaildirWalkMsgCallback msg_cb,
		     MuMaildirWalkDirCallback dir_cb, void *data)
{
	MuResult result;
	GSList *lst, *c;
	struct dirent *entry;
	
	lst = NULL;
	while ((entry = readdir (dir)))
		lst = g_slist_prepend (lst, dirent_copy(entry));
	
	/* we sort by inode; this makes things much faster on
	 * extfs2,3 */
#if HAVE_STRUCT_DIRENT_D_INO		
	c = lst = g_slist_sort (lst, (GCompareFunc)dirent_cmp);
#endif /*HAVE_STRUCT_DIRENT_D_INO*/	

	for (c = lst, result = MU_OK; c && result == MU_OK; c = g_slist_next(c)) {
		result = process_dir_entry (path, mdir,
					    (struct dirent*)c->data, 
					    msg_cb, dir_cb, data);
		/* hmmm, break on MU_ERROR as well? */
		if (result == MU_STOP)
			break;
	}

	g_slist_foreach (lst, (GFunc)dirent_destroy, NULL);
	g_slist_free (lst);
	
	return result;
}


static MuResult
process_dir (const char* path, const char* mdir,
	     MuMaildirWalkMsgCallback msg_cb, 
	     MuMaildirWalkDirCallback dir_cb, void *data)
{
	MuResult result;
	DIR* dir;
	
	/* if it has a noindex file, we ignore this dir */
	if (has_noindex_file (path)) {
		g_debug ("found .noindex: ignoring dir %s", path);
		return MU_OK;
	}

	dir = opendir (path);		
	if (G_UNLIKELY(!dir)) {
		g_warning ("%s: ignoring  %s: %s",  __FUNCTION__,
			   path, strerror(errno));
		return MU_OK;
	}
	
	if (dir_cb) {
		MuResult rv;
		rv = dir_cb (path, TRUE, data);
		if (rv != MU_OK) {
			closedir (dir);
			return rv;
		}
	}
	
	result = process_dir_entries (dir, path, mdir, msg_cb, dir_cb, data);
	closedir (dir);

	/* only run dir_cb if it exists and so far, things went ok */
	if (dir_cb && result == MU_OK)
		return dir_cb (path, FALSE, data);
	
	return result;
}


MuResult
mu_maildir_walk (const char *path, MuMaildirWalkMsgCallback cb_msg, 
		 MuMaildirWalkDirCallback cb_dir, void *data)
{
	MuResult rv;
	char *mypath;
	
	g_return_val_if_fail (path && cb_msg, MU_ERROR);
	g_return_val_if_fail (mu_util_check_dir(path, TRUE, FALSE), MU_ERROR);	
	
	/* strip the final / or \ */
	mypath = g_strdup (path);
	if (mypath[strlen(mypath)-1] == G_DIR_SEPARATOR)
		mypath[strlen(mypath)-1] = '\0';
	
	rv = process_dir (mypath, NULL, cb_msg, cb_dir, data);
	g_free (mypath);
	
	return rv;
}


static gboolean
clear_links (const gchar* dirname, DIR *dir, GError **err)
{
	struct dirent *entry;
	gboolean rv;
	
	rv = TRUE;
	errno = 0;
	while ((entry = readdir (dir))) {
		
		const char *fp;
		char *fullpath;
		unsigned char d_type;
		
		/* ignore empty, dot thingies */
		if (!entry->d_name || entry->d_name[0] == '.')
			continue;
		
		/* we have to copy the buffer from fullpath_s, because
		 * it returns a static buffer and we are
		 * recursive*/
		fp = mu_str_fullpath_s (dirname, entry->d_name);
		fullpath = g_newa (char, strlen(fp) + 1);
		strcpy (fullpath, fp);
		
		d_type = GET_DTYPE (entry, fullpath);
		
		/* ignore non-links / non-dirs */
		if (d_type != DT_LNK && d_type != DT_DIR)
			continue; 
				
		if (d_type == DT_LNK) {
			if (unlink (fullpath) != 0) {
				/* don't use err */
				g_warning  ("error unlinking %s: %s",
					    fullpath, strerror(errno));
				rv = FALSE;
			}
		} else /* DT_DIR, see check before*/
			rv = mu_maildir_clear_links (fullpath, err);
	}

	if (errno != 0)
		g_set_error (err, 0, MU_ERROR_FILE,
			     "file error: %s", strerror(errno));
	
	return (rv == FALSE && errno == 0);
}


gboolean
mu_maildir_clear_links (const gchar* path, GError **err)
{
	DIR *dir;
	gboolean rv;
	
	g_return_val_if_fail (path, FALSE);
	
	dir = opendir (path);		
	if (!dir) {
		g_set_error (err, 0, MU_ERROR_FILE_CANNOT_OPEN,
			     "failed to open %s: %s", path,
			     strerror(errno));
		return FALSE;
	}

	rv = clear_links (path, dir, err);
	closedir (dir);

	return rv;
}


/*
 * is this a 'new' msg or a 'cur' msg?; if new, we return
 * (in info) a ptr to the info part 
 */
enum _MsgType { MSG_TYPE_CUR, MSG_TYPE_NEW, MSG_TYPE_OTHER };
typedef enum _MsgType MsgType;

static MsgType
check_msg_type (const char *path, char **info)
{
	char *dir, *file;
	MsgType mtype;
		
	/* try to find the info part */
	/* note that we can use either the ':' or '!' as separator;
	 * the former is the official, but as it does not work on e.g. VFAT
	 * file systems, some Maildir implementations use the latter instead
	 * (or both). For example, Tinymail/modest does this. The python
	 * documentation at http://docs.python.org/lib/mailbox-maildir.html
	 * mentions the '!' as well as a 'popular choice'
	 */

	*info = NULL;
	dir = g_path_get_dirname(path);
	file = g_path_get_basename(path);
		
	if (!(*info = strrchr(file, ':')))
		*info = strrchr(file, '!');	/* Tinymail */
	if (*info)
		++(*info);	/* skip the ':' or '!' */

	if (g_str_has_suffix(dir, G_DIR_SEPARATOR_S "cur")) {
		if (!*info)
			g_debug("'cur' file, but no info part: %s", path);
		mtype = MSG_TYPE_CUR;
	} else if (g_str_has_suffix(dir, G_DIR_SEPARATOR_S "new")) {
		if (*info)
			g_debug("'new' file, ignoring info part: %s", path);
		mtype = MSG_TYPE_NEW;
	} else
		mtype = MSG_TYPE_OTHER;	/* file has been added explicitly as
					   a single message */
	if (*info)
		*info = g_strdup(*info);

	g_free(dir);
	g_free(file);

	return mtype;
}


MuMsgFlags
mu_maildir_get_flags_from_path (const char *path)
{
	MuMsgFlags flags;
	MsgType mtype;
	char *info = NULL, *cursor;

	g_return_val_if_fail (path, MU_MSG_FLAG_NONE);
	g_return_val_if_fail (!g_str_has_suffix(path, G_DIR_SEPARATOR_S),
			      MU_MSG_FLAG_NONE);

	mtype = check_msg_type (path, &info);
	if (mtype == MSG_TYPE_NEW) {	/* we ignore any new-msg flags */
		/* note NEW implies UNREAD */
		flags = MU_MSG_FLAG_NEW | MU_MSG_FLAG_UNREAD;
		goto leave;
	}

	flags = MU_MSG_FLAG_NONE;
	if ((mtype != MSG_TYPE_CUR && mtype != MSG_TYPE_OTHER) ||
	    !(info && info[0] == '2' && info[1] == ','))
		goto leave;
		
	for (cursor = info + 2; *cursor; ++cursor)
		flags |= mu_msg_flag_from_file_char (*cursor);

	/* the UNREAD pseudo flag => NEW OR NOT SEEN */
	if (!(flags & MU_MSG_FLAG_SEEN))
		flags |= MU_MSG_FLAG_UNREAD;		
leave:
	g_free(info);
	return flags;
}

/* note: returns static string, non-reentrant */
static const char*
get_flags_str_s (MuMsgFlags flags)
{
	int i;
	static char flagstr[7]; 

	i = 0;
		
	/* now, determine the flags to use */
	if (flags & MU_MSG_FLAG_DRAFT)
		flagstr[i++] = 'D';
	if (flags & MU_MSG_FLAG_FLAGGED)
		flagstr[i++] = 'F';
	if (flags & MU_MSG_FLAG_PASSED)
		flagstr[i++] = 'P';
	if (flags & MU_MSG_FLAG_REPLIED)
		flagstr[i++] = 'R';
	if (flags & MU_MSG_FLAG_SEEN)
		flagstr[i++] = 'S';
	if (flags & MU_MSG_FLAG_TRASHED)
		flagstr[i++] = 'T';
		
	flagstr[i] = '\0';

	return flagstr;
}


/*
 * take an exising message path, and return a new path, based on
 * whether it should be in 'new' or 'cur'; ie.
 *
 * /home/user/Maildir/foo/bar/cur/abc:2,F  and flags == MU_MSG_FLAG_NEW
 *     => /home/user/Maildir/foo/bar/new
 * and 
 * /home/user/Maildir/foo/bar/new/abc  and flags == MU_MSG_FLAG_REPLIED
 *    => /home/user/Maildir/foo/bar/cur
 *
 * so only difference is whether MuMsgFlags matches MU_MSG_FLAG_NEW is set or not
 * 
 */
static char*
get_new_dir_name (const char* oldpath, MuMsgFlags flags)
{
	char *newpath, *dirpart;
		
	/* g_path_get_dirname is not explicit about whether it ends in
	 * a dir-separator (\ or /), so we need to check both */
	const char* cur4 = G_DIR_SEPARATOR_S "cur";
	const char* cur5 = G_DIR_SEPARATOR_S "cur" G_DIR_SEPARATOR_S;
	const char* new4 = G_DIR_SEPARATOR_S "new";
	const char* new5 = G_DIR_SEPARATOR_S "new" G_DIR_SEPARATOR_S;
		
	g_return_val_if_fail (oldpath, NULL);
	/* if MU_MSG_FLAG_NEW is set, it must be the only flag */
	g_return_val_if_fail (flags & MU_MSG_FLAG_NEW ?
			      flags == MU_MSG_FLAG_NEW : TRUE, NULL);
		
	newpath = g_path_get_dirname (oldpath);
	if (g_str_has_suffix (newpath, cur4) || g_str_has_suffix (newpath, new4))
		dirpart = &newpath[strlen(newpath) - strlen(cur4)];
	else if (g_str_has_suffix (newpath, cur5) || g_str_has_suffix (newpath, new5))
		dirpart = &newpath[strlen(newpath) - strlen(cur5)];
	else {
		g_warning ("invalid maildir path: %s", oldpath);
		g_free (newpath);
		return NULL;
	}

	/* now, copy the desired dir part behind this */
	if (flags & MU_MSG_FLAG_NEW) 
		memcpy (dirpart, new4, strlen(new4) + 1);
	else
		memcpy (dirpart, cur4, strlen(cur4) + 1);
		
	return newpath;
}

/*
 * get a new filename for the message, based on the new flags; if the
 * message has MU_MSG_FLAG_NEW, it will loose its flags
 *
 */ 
static char*
get_new_file_name (const char *oldpath, MuMsgFlags flags)
{
	gchar *newname, *sep;
		
	/* if MU_MSG_FLAG_NEW is set, it must be the only flag */
	g_return_val_if_fail (flags & MU_MSG_FLAG_NEW ?
			      flags == MU_MSG_FLAG_NEW : TRUE, NULL);
		
	/* the normal separator is ':', but on e.g. vfat, '!' is seen
	 * as well */
	newname		= g_path_get_basename (oldpath);
	if (!newname) {
		g_warning ("invalid path: '%s'", oldpath);
		return NULL;
	}

	if (!(sep = g_strrstr (newname, ":")) &&
	    !(sep = g_strrstr (newname, "!"))) {
		g_warning ("not a valid msg file name: '%s'", oldpath);
		g_free (newname);
		return NULL;
	}

	if (flags & MU_MSG_FLAG_NEW)
		sep[0] = '\0'; /* remove all, including ':' or '!' */
	else {
		gchar *tmp;
		sep[1] = '\0'; /* remove flags, but keep ':' or '!' */
		sep[flags & MU_MSG_FLAG_NEW ? 0 : 1] = '\0';
		tmp = newname;
		newname = g_strdup_printf ("%s2,%s", newname, get_flags_str_s (flags));
		g_free (tmp);
	}

	return newname;
}

char*
mu_maildir_get_path_from_flags (const char *oldpath, MuMsgFlags newflags)
{
	char *newname, *newdir, *newpath;
	
	g_return_val_if_fail (oldpath, NULL);
	g_return_val_if_fail (newflags != MU_MSG_FLAG_NONE, NULL);
	/* if MU_MSG_FLAG_NEW is set, it must be the only flag */
	g_return_val_if_fail (newflags & MU_MSG_FLAG_NEW ?
			      newflags == MU_MSG_FLAG_NEW : TRUE, NULL);
	
	newname = get_new_file_name (oldpath, newflags);
	if (!newname)
		return NULL;

	newdir = get_new_dir_name (oldpath, newflags);
	if (!newdir) {
		g_free (newname);
		return NULL;
	}
				
	newpath = g_strdup_printf ("%s%c%s", newdir, G_DIR_SEPARATOR, newname);
	g_free (newname);
	g_free (newdir);
		
	return newpath;
}