more sync with 0.9.6cvs2
[claws.git] / src / imap.c
index 2ab293edf418791ea6f813f9986f3202e176b66c..fcda94df768cb66f4cfe58cba83bbf8dd087263f 100644 (file)
@@ -63,6 +63,7 @@ typedef struct _IMAPFolderItem        IMAPFolderItem;
 #include "prefs_account.h"
 
 #define IMAP_FOLDER(obj)       ((IMAPFolder *)obj)
+#define IMAP_FOLDER_ITEM(obj)  ((IMAPFolderItem *)obj)
 #define IMAP_SESSION(obj)      ((IMAPSession *)obj)
 
 struct _IMAPFolder
@@ -79,11 +80,16 @@ struct _IMAPSession
 {
        Session session;
 
+       gboolean authenticated;
+
        gchar **capability;
+       gboolean uidplus;
+
        gchar *mbox;
-       time_t last_access_time;
-       gboolean authenticated;
        guint cmd_count;
+
+       /* CLAWS */
+       time_t last_access_time;
        gboolean folder_content_changed;
        guint exists;
 };
@@ -103,7 +109,6 @@ struct _IMAPNameSpace
 #define IMAP_ERROR     7
 
 #define IMAPBUFSIZE    8192
-#define IMAPCMDLIMIT   1000
 
 typedef enum
 {
@@ -126,6 +131,8 @@ typedef enum
 #define IMAPS_PORT     993
 #endif
 
+#define IMAP_CMD_LIMIT 1000
+
 #define QUOTE_IF_REQUIRED(out, str)                            \
 {                                                              \
        if (*str != '"' && strpbrk(str, " \t(){}%*") != NULL) { \
@@ -152,55 +159,72 @@ struct _IMAPFolderItem
        GSList *uid_list;
 };
 
-static Folder *imap_folder_new(const gchar * name, const gchar * path);
-static void imap_folder_destroy(Folder * folder);
-
-static IMAPSession *imap_session_new(const PrefsAccount * account);
-static void imap_session_authenticate(IMAPSession * session,
-                                     const PrefsAccount * account);
-static void imap_session_destroy(Session * session);
-
-static gchar *imap_fetch_msg(Folder * folder, FolderItem * item, gint uid);
-static gint imap_add_msg(Folder * folder,
-                        FolderItem * dest,
-                        const gchar * file, MsgFlags * flags);
-static gint imap_add_msgs(Folder * folder, FolderItem * dest,
-                         GSList * file_list,
-                         MsgNumberList **newnum_list);
-
-static gint imap_copy_msg(Folder * folder,
-                         FolderItem * dest, MsgInfo * msginfo);
-
-static gint imap_remove_msg(Folder * folder, FolderItem * item, gint uid);
-static gint imap_remove_all_msg(Folder * folder, FolderItem * item);
-
-static gboolean imap_is_msg_changed(Folder * folder,
-                                   FolderItem * item, MsgInfo * msginfo);
-
-static gint imap_close(Folder * folder, FolderItem * item);
-
-static void imap_scan_tree(Folder * folder);
-
-static gint imap_create_tree(Folder * folder);
-
-static FolderItem *imap_create_folder(Folder * folder,
-                                     FolderItem * parent,
-                                     const gchar * name);
-static gint imap_rename_folder(Folder * folder,
-                              FolderItem * item, const gchar * name);
-static gint imap_remove_folder(Folder * folder, FolderItem * item);
-
-
 static void imap_folder_init           (Folder         *folder,
                                         const gchar    *name,
                                         const gchar    *path);
 
+static Folder  *imap_folder_new        (const gchar    *name,
+                                        const gchar    *path);
+static void     imap_folder_destroy    (Folder         *folder);
+
+static IMAPSession *imap_session_new   (const PrefsAccount     *account);
+static void    imap_session_authenticate(IMAPSession           *session,
+                                         const PrefsAccount    *account);
+static void    imap_session_destroy    (Session        *session);
+
+static gchar   *imap_fetch_msg         (Folder         *folder, 
+                                        FolderItem     *item, 
+                                        gint            uid);
+static gint    imap_add_msg            (Folder         *folder,
+                                        FolderItem     *dest,
+                                        const gchar    *file, 
+                                        MsgFlags       *flags);
+static gint    imap_add_msgs           (Folder         *folder, 
+                                        FolderItem     *dest,
+                                        GSList         *file_list,
+                                        GRelation      *relation);
+
+static gint    imap_copy_msg           (Folder         *folder,
+                                        FolderItem     *dest, 
+                                        MsgInfo        *msginfo);
+static gint    imap_copy_msgs          (Folder         *folder, 
+                                        FolderItem     *dest, 
+                                        MsgInfoList    *msglist, 
+                                        GRelation      *relation);
+
+static gint    imap_remove_msg         (Folder         *folder, 
+                                        FolderItem     *item, 
+                                        gint            uid);
+static gint    imap_remove_all_msg     (Folder         *folder, 
+                                        FolderItem     *item);
+
+static gboolean imap_is_msg_changed    (Folder         *folder,
+                                        FolderItem     *item, 
+                                        MsgInfo        *msginfo);
+
+static gint    imap_close              (Folder         *folder, 
+                                        FolderItem     *item);
+
+static gint    imap_scan_tree          (Folder         *folder);
+
+static gint    imap_create_tree        (Folder         *folder);
+
+static FolderItem *imap_create_folder  (Folder         *folder,
+                                        FolderItem     *parent,
+                                        const gchar    *name);
+static gint    imap_rename_folder      (Folder         *folder,
+                                        FolderItem     *item, 
+                                        const gchar    *name);
+static gint    imap_remove_folder      (Folder         *folder, 
+                                        FolderItem     *item);
+
 static FolderItem *imap_folder_item_new        (Folder         *folder);
 static void imap_folder_item_destroy   (Folder         *folder,
                                         FolderItem     *item);
 
 static IMAPSession *imap_session_get   (Folder         *folder);
 
+static gint imap_greeting              (IMAPSession    *session);
 static gint imap_auth                  (IMAPSession    *session,
                                         const gchar    *user,
                                         const gchar    *pass,
@@ -213,16 +237,16 @@ static GSList *imap_parse_list            (IMAPFolder     *folder,
                                         const gchar    *real_path,
                                         gchar          *separator);
 
-static void imap_create_missing_folders        (Folder                 *folder);
+static void imap_create_missing_folders        (Folder         *folder);
 static FolderItem *imap_create_special_folder
                                        (Folder                 *folder,
                                         SpecialFolderItemType   stype,
                                         const gchar            *name);
 
-static gint imap_do_copy               (Folder         *folder,
+static gint imap_do_copy_msgs          (Folder         *folder,
                                         FolderItem     *dest,
-                                        MsgInfo        *msginfo,
-                                        gboolean        remove_source);
+                                        MsgInfoList    *msglist,
+                                        GRelation      *relation);
 
 static void imap_delete_all_cached_messages    (FolderItem     *item);
 
@@ -291,12 +315,10 @@ static MsgFlags imap_parse_flags  (const gchar    *flag_str);
 static MsgInfo *imap_parse_envelope    (SockInfo       *sock,
                                         FolderItem     *item,
                                         GString        *line_str);
-static gint imap_greeting              (IMAPSession    *session);
+
 static gboolean imap_has_capability    (IMAPSession    *session,
                                         const gchar    *cap);
-void imap_free_capabilities            (IMAPSession    *session);
-static const IMAPSet numberlist_to_imapset
-                                       (MsgNumberList *list);
+static void imap_free_capabilities     (IMAPSession    *session);
 
 /* low-level IMAP4rev1 commands */
 static gint imap_cmd_authenticate
@@ -304,32 +326,32 @@ static gint imap_cmd_authenticate
                                 const gchar    *user,
                                 const gchar    *pass,
                                 IMAPAuthType    type);
-static gint imap_cmd_login     (IMAPSession    *sock,
+static gint imap_cmd_login     (IMAPSession    *session,
                                 const gchar    *user,
                                 const gchar    *pass);
-static gint imap_cmd_logout    (IMAPSession    *sock);
-static gint imap_cmd_noop      (IMAPSession    *sock);
-static gint imap_cmd_starttls  (IMAPSession    *sock);
-static gint imap_cmd_namespace (IMAPSession    *sock,
+static gint imap_cmd_logout    (IMAPSession    *session);
+static gint imap_cmd_noop      (IMAPSession    *session);
+static gint imap_cmd_starttls  (IMAPSession    *session);
+static gint imap_cmd_namespace (IMAPSession    *session,
                                 gchar         **ns_str);
 static gint imap_cmd_list      (IMAPSession    *session,
                                 const gchar    *ref,
                                 const gchar    *mailbox,
                                 GPtrArray      *argbuf);
-static gint imap_cmd_do_select (IMAPSession    *sock,
+static gint imap_cmd_do_select (IMAPSession    *session,
                                 const gchar    *folder,
                                 gboolean        examine,
                                 gint           *exists,
                                 gint           *recent,
                                 gint           *unseen,
                                 guint32        *uid_validity);
-static gint imap_cmd_select    (IMAPSession    *sock,
+static gint imap_cmd_select    (IMAPSession    *session,
                                 const gchar    *folder,
                                 gint           *exists,
                                 gint           *recent,
                                 gint           *unseen,
                                 guint32        *uid_validity);
-static gint imap_cmd_examine   (IMAPSession    *sock,
+static gint imap_cmd_examine   (IMAPSession    *session,
                                 const gchar    *folder,
                                 gint           *exists,
                                 gint           *recent,
@@ -340,9 +362,9 @@ static gint imap_cmd_create (IMAPSession    *sock,
 static gint imap_cmd_rename    (IMAPSession    *sock,
                                 const gchar    *oldfolder,
                                 const gchar    *newfolder);
-static gint imap_cmd_delete    (IMAPSession    *sock,
+static gint imap_cmd_delete    (IMAPSession    *session,
                                 const gchar    *folder);
-static gint imap_cmd_envelope  (IMAPSession    *sock,
+static gint imap_cmd_envelope  (IMAPSession    *session,
                                 IMAPSet         set);
 static gint imap_cmd_fetch     (IMAPSession    *sock,
                                 guint32         uid,
@@ -351,23 +373,24 @@ static gint imap_cmd_append       (IMAPSession    *session,
                                 const gchar    *destfolder,
                                 const gchar    *file,
                                 IMAPFlags       flags,
-                                gint32         *newuid);
-static gint imap_cmd_copy      (IMAPSession    *session,
-                                gint32         msgnum,
-                                const gchar    *destfolder,
-                                gint32         *new_uid);
-static gint imap_cmd_store     (IMAPSession    *sock,
+                                guint32        *new_uid);
+static gint imap_cmd_copy       (IMAPSession    *session, 
+                                 const gchar    *seq_set, 
+                                 const gchar    *destfolder,
+                                GRelation      *uid_mapping);
+static gint imap_cmd_store     (IMAPSession    *session,
                                 IMAPSet         set,
                                 gchar          *sub_cmd);
-static gint imap_cmd_expunge   (IMAPSession    *sock);
-static gint imap_cmd_close     (IMAPSession    *session);
+static gint imap_cmd_expunge   (IMAPSession    *session,
+                                IMAPSet         seq_set);
+static gint imap_cmd_close      (IMAPSession    *session);
 
 static gint imap_cmd_ok                (IMAPSession    *session,
                                 GPtrArray      *argbuf);
-static void imap_gen_send      (IMAPSession    *sock,
+static void imap_gen_send      (IMAPSession    *session,
                                 const gchar    *format, ...);
-static gint imap_gen_recv      (IMAPSession    *sock,
-                                gchar         **buf);
+static gint imap_gen_recv      (IMAPSession    *session,
+                                gchar         **ret);
 
 /* misc utility functions */
 static gchar *strchr_cpy                       (const gchar    *src,
@@ -388,18 +411,23 @@ static void imap_path_separator_subst             (gchar          *str,
 static gchar *imap_modified_utf7_to_locale     (const gchar    *mutf7_str);
 static gchar *imap_locale_to_modified_utf7     (const gchar    *from);
 
+static GSList *imap_get_seq_set_from_numlist    (MsgNumberList  *msglist);
+static GSList *imap_get_seq_set_from_msglist   (MsgInfoList    *msglist);
+static void imap_seq_set_free                   (GSList         *seq_list);
+
 static gboolean imap_rename_folder_func                (GNode          *node,
                                                 gpointer        data);
 static gint imap_get_num_list                  (Folder         *folder,
                                                 FolderItem     *item,
-                                                GSList        **list);
+                                                GSList        **list,
+                                                gboolean       *old_uids_valid);
 static GSList *imap_get_msginfos               (Folder         *folder,
                                                 FolderItem     *item,
                                                 GSList         *msgnum_list);
 static MsgInfo *imap_get_msginfo               (Folder         *folder,
                                                 FolderItem     *item,
                                                 gint            num);
-static gboolean imap_check_msgnum_validity     (Folder         *folder,
+static gboolean imap_scan_required             (Folder         *folder,
                                                 FolderItem     *item);
 static void imap_change_flags                  (Folder         *folder,
                                                 FolderItem     *item,
@@ -409,7 +437,7 @@ static gchar *imap_folder_get_path          (Folder         *folder);
 static gchar *imap_item_get_path               (Folder         *folder,
                                                 FolderItem     *item);
 
-FolderClass imap_class =
+static FolderClass imap_class =
 {
        F_IMAP,
        "imap",
@@ -433,7 +461,7 @@ FolderClass imap_class =
        NULL,
        NULL,
        NULL,
-       imap_check_msgnum_validity,
+       imap_scan_required,
 
        /* Message functions */
        imap_get_msginfo,
@@ -442,7 +470,7 @@ FolderClass imap_class =
        imap_add_msg,
        imap_add_msgs,
        imap_copy_msg,
-       NULL,
+       imap_copy_msgs,
        imap_remove_msg,
        imap_remove_all_msg,
        imap_is_msg_changed,
@@ -454,7 +482,7 @@ FolderClass *imap_get_class(void)
        return &imap_class;
 }
 
-Folder *imap_folder_new(const gchar *name, const gchar *path)
+static Folder *imap_folder_new(const gchar *name, const gchar *path)
 {
        Folder *folder;
 
@@ -465,7 +493,7 @@ Folder *imap_folder_new(const gchar *name, const gchar *path)
        return folder;
 }
 
-void imap_folder_destroy(Folder *folder)
+static void imap_folder_destroy(Folder *folder)
 {
        gchar *dir;
 
@@ -526,13 +554,53 @@ static void imap_reset_uid_lists(Folder *folder)
        g_node_traverse(folder->node, G_IN_ORDER, G_TRAVERSE_ALL, -1, imap_reset_uid_lists_func, NULL); 
 }
 
+/* Send CAPABILITY, and examine the server's response to see whether this
+ * connection is pre-authenticated or not and build a list of CAPABILITIES. */
+static gint imap_greeting(IMAPSession *session)
+{
+       gchar *capstr;
+       GPtrArray *argbuf;
+
+       imap_gen_send(session, "CAPABILITY");
+       
+       argbuf = g_ptr_array_new();
+
+       if (imap_cmd_ok(session, argbuf) != IMAP_SUCCESS ||
+           ((capstr = search_array_str(argbuf, "CAPABILITY ")) == NULL)) {
+               ptr_array_free_strings(argbuf);
+               g_ptr_array_free(argbuf, TRUE);
+               return -1;
+       }
+
+       session->authenticated = search_array_str(argbuf, "PREAUTH") != NULL;
+       
+       capstr += strlen("CAPABILITY ");
+
+       IMAP_SESSION(session)->capability = g_strsplit(capstr, " ", 0);
+       
+       ptr_array_free_strings(argbuf);
+       g_ptr_array_free(argbuf, TRUE);
+
+       if (imap_has_capability(session, "UIDPLUS")) 
+               session->uidplus = TRUE; 
+
+       return 0;
+}
+
 static gint imap_auth(IMAPSession *session, const gchar *user, const gchar *pass,
                      IMAPAuthType type)
 {
+       gint ok;
+
        if (type == 0 || type == IMAP_AUTH_LOGIN)
-               return imap_cmd_login(session, user, pass);
+               ok = imap_cmd_login(session, user, pass);
        else
-               return imap_cmd_authenticate(session, user, pass, type);
+               ok = imap_cmd_authenticate(session, user, pass, type);
+
+       if (ok == IMAP_SUCCESS)
+               session->authenticated = TRUE;
+
+       return ok;
 }
 
 static IMAPSession *imap_session_get(Folder *folder)
@@ -614,7 +682,7 @@ static IMAPSession *imap_session_get(Folder *folder)
        return IMAP_SESSION(session);
 }
 
-IMAPSession *imap_session_new(const PrefsAccount *account)
+static IMAPSession *imap_session_new(const PrefsAccount *account)
 {
        IMAPSession *session;
        SockInfo *imap_sock;
@@ -668,8 +736,8 @@ IMAPSession *imap_session_new(const PrefsAccount *account)
 
        session->capability = NULL;
 
-       session->mbox = NULL;
        session->authenticated = FALSE;
+       session->mbox = NULL;
        session->cmd_count = 0;
 
        /* Only need to log in if the connection was not PREAUTH */
@@ -679,7 +747,8 @@ IMAPSession *imap_session_new(const PrefsAccount *account)
        }
 
 #if USE_OPENSSL
-       if (account->ssl_imap == SSL_STARTTLS && imap_has_capability(session, "STARTTLS")) {
+       if (account->ssl_imap == SSL_STARTTLS && 
+           imap_has_capability(session, "STARTTLS")) {
                gint ok;
 
                ok = imap_cmd_starttls(session);
@@ -688,13 +757,15 @@ IMAPSession *imap_session_new(const PrefsAccount *account)
                        session_destroy(SESSION(session));
                        return NULL;
                }
-               if (!ssl_init_socket_with_method(SESSION(session)->sock, SSL_METHOD_TLSv1)) {
+               if (!ssl_init_socket_with_method(SESSION(session)->sock, 
+                   SSL_METHOD_TLSv1)) {
                        session_destroy(SESSION(session));
                        return NULL;
                }
 
                imap_free_capabilities(session);
                session->authenticated = FALSE;
+               session->uidplus = FALSE;
                session->cmd_count = 1;
 
                if (imap_greeting(session) != IMAP_SUCCESS) {
@@ -709,7 +780,8 @@ IMAPSession *imap_session_new(const PrefsAccount *account)
        return session;
 }
 
-void imap_session_authenticate(IMAPSession *session, const PrefsAccount *account)
+static void imap_session_authenticate(IMAPSession *session, 
+                                     const PrefsAccount *account)
 {
        gchar *pass;
 
@@ -733,16 +805,15 @@ void imap_session_authenticate(IMAPSession *session, const PrefsAccount *account
        session->authenticated = TRUE;
 }
 
-void imap_session_destroy(Session *session)
+static void imap_session_destroy(Session *session)
 {
+       imap_free_capabilities(IMAP_SESSION(session));
+       g_free(IMAP_SESSION(session)->mbox);
        sock_close(session->sock);
        session->sock = NULL;
-
-       g_free(IMAP_SESSION(session)->mbox);
-       imap_free_capabilities(IMAP_SESSION(session));
 }
 
-gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
+static gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
 {
        gchar *path, *filename;
        IMAPSession *session;
@@ -756,7 +827,7 @@ gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
                make_dir_hier(path);
        filename = g_strconcat(path, G_DIR_SEPARATOR_S, itos(uid), NULL);
        g_free(path);
+
        if (is_file_exist(filename)) {
                debug_print("message %d has been already cached.\n", uid);
                return filename;
@@ -788,34 +859,34 @@ gchar *imap_fetch_msg(Folder *folder, FolderItem *item, gint uid)
        return filename;
 }
 
-gint imap_add_msg(Folder *folder, FolderItem *dest, const gchar *file, MsgFlags *flags)
+static gint imap_add_msg(Folder *folder, FolderItem *dest, 
+                        const gchar *file, MsgFlags *flags)
 {
        gint ret;
        GSList file_list;
        MsgFileInfo fileinfo;
-       MsgNumberList *msgnum_list = NULL;
 
        g_return_val_if_fail(file != NULL, -1);
 
+       fileinfo.msginfo = NULL;
        fileinfo.file = (gchar *)file;
        fileinfo.flags = flags;
        file_list.data = &fileinfo;
        file_list.next = NULL;
 
-       ret = imap_add_msgs(folder, dest, &file_list, &msgnum_list);
-       g_slist_free(msgnum_list);
+       ret = imap_add_msgs(folder, dest, &file_list, NULL);
        return ret;
 }
 
-gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
-                  MsgNumberList **newnum_list)
+static gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
+                  GRelation *relation)
 {
        gchar *destdir;
        IMAPSession *session;
        guint32 last_uid = 0;
        GSList *cur;
        MsgFileInfo *fileinfo;
-       gint ok, newnum;
+       gint ok;
 
        g_return_val_if_fail(folder != NULL, -1);
        g_return_val_if_fail(dest != NULL, -1);
@@ -828,6 +899,7 @@ gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
 
        for (cur = file_list; cur != NULL; cur = cur->next) {
                IMAPFlags iflags = 0;
+               guint32 new_uid = 0;
 
                fileinfo = (MsgFileInfo *)cur->data;
 
@@ -846,7 +918,8 @@ gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
                    dest->stype == F_TRASH)
                        iflags |= IMAP_FLAG_SEEN;
 
-               ok = imap_cmd_append(session, destdir, fileinfo->file, iflags, &newnum);
+               ok = imap_cmd_append(session, destdir, fileinfo->file, iflags, 
+                                    &new_uid);
 
                if (ok != IMAP_SUCCESS) {
                        g_warning("can't append message %s\n", fileinfo->file);
@@ -854,9 +927,12 @@ gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
                        return -1;
                }
 
-               *newnum_list = g_slist_append(*newnum_list, GINT_TO_POINTER(newnum));
-               if (newnum > last_uid)
-                       last_uid = newnum;
+               if (relation != NULL)
+                       g_relation_insert(relation, fileinfo->msginfo != NULL ? 
+                                         (gpointer) fileinfo->msginfo : (gpointer) fileinfo,
+                                         GINT_TO_POINTER(dest->last_num + 1));
+               if (last_uid < new_uid)
+                       last_uid = new_uid;
        }
 
        g_free(destdir);
@@ -864,89 +940,127 @@ gint imap_add_msgs(Folder *folder, FolderItem *dest, GSList *file_list,
        return last_uid;
 }
 
-static gint imap_do_copy(Folder *folder, FolderItem *dest, MsgInfo *msginfo,
-                        gboolean remove_source)
+static gint imap_do_copy_msgs(Folder *folder, FolderItem *dest, 
+                             MsgInfoList *msglist, GRelation *relation)
 {
+       FolderItem *src;
        gchar *destdir;
+       GSList *seq_list, *cur;
+       MsgInfo *msginfo;
        IMAPSession *session;
-       guint32 newuid = 0;
-       gint ok;
+       gint ok = IMAP_SUCCESS;
+       GRelation *uid_mapping;
+       gint last_num = 0;
        
        g_return_val_if_fail(folder != NULL, -1);
-       g_return_val_if_fail(FOLDER_CLASS(folder) == &imap_class, -1);
        g_return_val_if_fail(dest != NULL, -1);
-       g_return_val_if_fail(msginfo != NULL, -1);
+       g_return_val_if_fail(msglist != NULL, -1);
 
        session = imap_session_get(folder);
        if (!session) return -1;
 
-       if (msginfo->folder == dest) {
+       msginfo = (MsgInfo *)msglist->data;
+
+       src = msginfo->folder;
+       if (src == dest) {
                g_warning("the src folder is identical to the dest.\n");
                return -1;
        }
 
-       destdir = imap_get_real_path(IMAP_FOLDER(folder), dest->path);
-
-       /* ensure source folder selected */
        ok = imap_select(session, IMAP_FOLDER(folder), msginfo->folder->path,
                         NULL, NULL, NULL, NULL);
        if (ok != IMAP_SUCCESS)
-               return -1;
-        
-       if (remove_source)
-               debug_print("Moving message %s%c%d to %s ...\n",
-                           msginfo->folder->path, G_DIR_SEPARATOR,
-                           msginfo->msgnum, destdir);
-       else
-               debug_print("Copying message %s%c%d to %s ...\n",
-                           msginfo->folder->path, G_DIR_SEPARATOR,
-                           msginfo->msgnum, destdir);
+               return ok;
 
-       ok = imap_cmd_copy(session, msginfo->msgnum, destdir, &newuid);
+       destdir = imap_get_real_path(IMAP_FOLDER(folder), dest->path);
+       seq_list = imap_get_seq_set_from_msglist(msglist);
+       uid_mapping = g_relation_new(2);
+       g_relation_index(uid_mapping, 0, g_direct_hash, g_direct_equal);
+       
+       for (cur = seq_list; cur != NULL; cur = g_slist_next(cur)) {
+               gchar *seq_set = (gchar *)cur->data;
 
-       if (ok == IMAP_SUCCESS && remove_source) {
-               MsgNumberList numlist;
+               debug_print("Copying message %s%c[%s] to %s ...\n",
+                           src->path, G_DIR_SEPARATOR,
+                           seq_set, destdir);
 
-               numlist.next = NULL;
-               numlist.data = GINT_TO_POINTER(msginfo->msgnum);
-               
-               imap_set_message_flags(session, &numlist,
-                                      IMAP_FLAG_DELETED, TRUE);
-               ok = imap_cmd_expunge(session);
+               ok = imap_cmd_copy(session, seq_set, destdir, uid_mapping);
+               if (ok != IMAP_SUCCESS) {
+                       g_relation_destroy(uid_mapping);
+                       imap_seq_set_free(seq_list);
+                       return -1;
+               }
        }
 
+       for (cur = msglist; cur != NULL; cur = g_slist_next(cur)) {
+               MsgInfo *msginfo = (MsgInfo *)cur->data;
+               GTuples *tuples;
+
+               tuples = g_relation_select(uid_mapping, 
+                                          GINT_TO_POINTER(msginfo->msgnum),
+                                          0);
+               if (tuples->len > 0) {
+                       gint num = GPOINTER_TO_INT(g_tuples_index(tuples, 0, 1));
+                       g_relation_insert(relation, msginfo,
+                                         GPOINTER_TO_INT(num));
+                       if (num > last_num)
+                               last_num = num;
+               } else
+                       g_relation_insert(relation, msginfo,
+                                         GPOINTER_TO_INT(0));
+               g_tuples_destroy(tuples);
+       }
+
+       imap_seq_set_free(seq_list);
+
        g_free(destdir);
 
        if (ok == IMAP_SUCCESS)
-               return newuid;
+               return last_num;
        else
                return -1;
 }
 
-gint imap_copy_msg(Folder *folder, FolderItem *dest, MsgInfo *msginfo)
+static gint imap_copy_msg(Folder *folder, FolderItem *dest, MsgInfo *msginfo)
 {
-       gchar *srcfile;
-       gint ret = 0;
+       GSList msglist;
+
+       g_return_val_if_fail(msginfo != NULL, -1);
+
+       msglist.data = msginfo;
+       msglist.next = NULL;
+
+       return imap_copy_msgs(folder, dest, &msglist, NULL);
+}
+
+static gint imap_copy_msgs(Folder *folder, FolderItem *dest, 
+                   MsgInfoList *msglist, GRelation *relation)
+{
+       MsgInfo *msginfo;
+       GSList *file_list;
+       gint ret;
 
        g_return_val_if_fail(folder != NULL, -1);
        g_return_val_if_fail(dest != NULL, -1);
-       g_return_val_if_fail(msginfo != NULL, -1);
+       g_return_val_if_fail(msglist != NULL, -1);
+
+       msginfo = (MsgInfo *)msglist->data;
        g_return_val_if_fail(msginfo->folder != NULL, -1);
 
        if (folder == msginfo->folder->folder)
-               return imap_do_copy(folder, dest, msginfo, FALSE);
+               return imap_do_copy_msgs(folder, dest, msglist, relation);
 
-       srcfile = procmsg_get_message_file(msginfo);
-       if (!srcfile) return -1;
+       file_list = procmsg_get_message_file_list(msglist);
+       g_return_val_if_fail(file_list != NULL, -1);
 
-       ret = imap_add_msg(folder, dest, srcfile, NULL);
+       ret = imap_add_msgs(folder, dest, file_list, relation);
 
-       g_free(srcfile);
+       procmsg_message_file_list_free(file_list);
 
        return ret;
 }
 
-gint imap_remove_msg(Folder *folder, FolderItem *item, gint uid)
+static gint imap_remove_msg(Folder *folder, FolderItem *item, gint uid)
 {
        gint ok;
        IMAPSession *session;
@@ -976,12 +1090,22 @@ gint imap_remove_msg(Folder *folder, FolderItem *item, gint uid)
                return ok;
        }
 
-       ok = imap_cmd_expunge(session);
+       if (!session->uidplus) {
+               ok = imap_cmd_expunge(session, NULL);
+       } else {
+               gchar *uidstr;
+
+               uidstr = g_strdup_printf("%u", uid);
+               ok = imap_cmd_expunge(session, uidstr);
+               g_free(uidstr);
+       }
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't expunge\n"));
                return ok;
        }
 
+       IMAP_FOLDER_ITEM(item)->uid_list = g_slist_remove(
+           IMAP_FOLDER_ITEM(item)->uid_list, numlist.data);
        dir = folder_item_get_path(item);
        if (is_dir_exist(dir))
                remove_numbered_files(dir, uid, uid);
@@ -990,10 +1114,8 @@ gint imap_remove_msg(Folder *folder, FolderItem *item, gint uid)
        return IMAP_SUCCESS;
 }
 
-gint imap_remove_all_msg(Folder *folder, FolderItem *item)
+static gint imap_remove_all_msg(Folder *folder, FolderItem *item)
 {
-        gint exists, recent, unseen;
-        guint32 uid_validity;
        gint ok;
        IMAPSession *session;
        gchar *dir;
@@ -1005,21 +1127,18 @@ gint imap_remove_all_msg(Folder *folder, FolderItem *item)
        if (!session) return -1;
 
        ok = imap_select(session, IMAP_FOLDER(folder), item->path,
-                        &exists, &recent, &unseen, &uid_validity);
+                        NULL, NULL, NULL, NULL);
        if (ok != IMAP_SUCCESS)
                return ok;
-       if (exists == 0)
-               return IMAP_SUCCESS;
 
-       imap_gen_send(session,
-                     "STORE 1:%d +FLAGS (\\Deleted)", exists);
+       imap_gen_send(session, "STORE 1:* +FLAGS.SILENT (\\Deleted)");
        ok = imap_cmd_ok(session, NULL);
        if (ok != IMAP_SUCCESS) {
-               log_warning(_("can't set deleted flags: 1:%d\n"), exists);
+               log_warning(_("can't set deleted flags: 1:*\n"));
                return ok;
        }
 
-       ok = imap_cmd_expunge(session);
+       ok = imap_cmd_expunge(session, NULL);
        if (ok != IMAP_SUCCESS) {
                log_warning(_("can't expunge\n"));
                return ok;
@@ -1033,23 +1152,28 @@ gint imap_remove_all_msg(Folder *folder, FolderItem *item)
        return IMAP_SUCCESS;
 }
 
-gboolean imap_is_msg_changed(Folder *folder, FolderItem *item, MsgInfo *msginfo)
+static gboolean imap_is_msg_changed(Folder *folder, FolderItem *item,
+                                   MsgInfo *msginfo)
 {
        /* TODO: properly implement this method */
        return FALSE;
 }
 
-gint imap_close(Folder *folder, FolderItem *item)
+static gint imap_close(Folder *folder, FolderItem *item)
 {
        gint ok;
        IMAPSession *session;
 
        g_return_val_if_fail(folder != NULL, -1);
+       g_return_val_if_fail(item != NULL, -1);
+       g_return_val_if_fail(item->path != NULL, -1);
 
        session = imap_session_get(folder);
        if (!session) return -1;
 
        if (session->mbox) {
+               if (strcmp2(session->mbox, item->path) != 0) return -1;
+
                ok = imap_cmd_close(session);
                if (ok != IMAP_SUCCESS)
                        log_warning(_("can't close folder\n"));
@@ -1063,14 +1187,14 @@ gint imap_close(Folder *folder, FolderItem *item)
        return 0;
 }
 
-void imap_scan_tree(Folder *folder)
+static gint imap_scan_tree(Folder *folder)
 {
-       FolderItem *item;
+       FolderItem *item = NULL;
        IMAPSession *session;
        gchar *root_folder = NULL;
 
-       g_return_if_fail(folder != NULL);
-       g_return_if_fail(folder->account != NULL);
+       g_return_val_if_fail(folder != NULL, -1);
+       g_return_val_if_fail(folder->account != NULL, -1);
 
        session = imap_session_get(folder);
        if (!session) {
@@ -1078,25 +1202,48 @@ void imap_scan_tree(Folder *folder)
                        folder_tree_destroy(folder);
                        item = folder_item_new(folder, folder->name, NULL);
                        item->folder = folder;
-                       folder->node = g_node_new(item);
+                       folder->node = item->node = g_node_new(item);
                }
-               return;
+               return -1;
        }
 
        if (folder->account->imap_dir && *folder->account->imap_dir) {
-               Xstrdup_a(root_folder, folder->account->imap_dir, return);
+               gchar *real_path;
+
+               Xstrdup_a(root_folder, folder->account->imap_dir, return -1);
                strtailchomp(root_folder, '/');
-               debug_print("IMAP root directory: %s\n", root_folder);
+               extract_quote(root_folder, '"');
+               real_path = imap_get_real_path
+                       (IMAP_FOLDER(folder), root_folder);
+               debug_print("IMAP root directory: %s\n", real_path);
+               if (imap_status(session, IMAP_FOLDER(folder), root_folder,
+                                   NULL, NULL, NULL, NULL, NULL)
+                   != IMAP_SUCCESS) {
+                       if (imap_cmd_create(session, real_path)
+                           != IMAP_SUCCESS) {
+                               log_warning(_("can't create root folder %s\n"),
+                                           real_path);
+                               g_free(real_path);
+                               return -1;
+                       }
+               }
+               g_free(real_path);
        }
 
-       item = folder_item_new(folder, folder->name, root_folder);
-       item->folder = folder;
-       item->no_select = TRUE;
-       folder->node = g_node_new(item);
-
-       imap_scan_tree_recursive(session, item);
+       if (folder->node)
+               item = FOLDER_ITEM(folder->node->data);
+       if (!item || ((item->path || root_folder) &&
+                     strcmp2(item->path, root_folder) != 0)) {
+               folder_tree_destroy(folder);
+               item = folder_item_new(folder, folder->name, root_folder);
+               item->folder = folder;
+               folder->node = item->node = g_node_new(item);
+       }
 
+       imap_scan_tree_recursive(session, FOLDER_ITEM(folder->node->data));
        imap_create_missing_folders(folder);
+
+       return 0;
 }
 
 static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
@@ -1105,6 +1252,7 @@ static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
        IMAPFolder *imapfolder;
        FolderItem *new_item;
        GSList *item_list, *cur;
+       GNode *node;
        gchar *real_path;
        gchar *wildcard_path;
        gchar separator;
@@ -1114,13 +1262,13 @@ static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
        g_return_val_if_fail(item->folder != NULL, -1);
        g_return_val_if_fail(item->no_sub == FALSE, -1);
 
-       folder = FOLDER(item->folder);
+       folder = item->folder;
        imapfolder = IMAP_FOLDER(folder);
 
        separator = imap_get_path_separator(imapfolder, item->path);
 
-       if (item->folder->ui_func)
-               item->folder->ui_func(folder, item, folder->ui_func_data);
+       if (folder->ui_func)
+               folder->ui_func(folder, item, folder->ui_func_data);
 
        if (item->path) {
                wildcard[0] = separator;
@@ -1144,16 +1292,59 @@ static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
        item_list = imap_parse_list(imapfolder, session, real_path, NULL);
        g_free(real_path);
 
+       node = item->node->children;
+       while (node != NULL) {
+               FolderItem *old_item = FOLDER_ITEM(node->data);
+               GNode *next = node->next;
+
+               new_item = NULL;
+               for (cur = item_list; cur != NULL; cur = cur->next) {
+                       FolderItem *cur_item = FOLDER_ITEM(cur->data);
+                       if (!strcmp2(old_item->path, cur_item->path)) {
+                               new_item = cur_item;
+                               break;
+                       }
+               }
+               if (!new_item) {
+                       debug_print("folder '%s' not found. removing...\n",
+                                   old_item->path);
+                       folder_item_remove(old_item);
+               } else {
+                       old_item->no_sub = new_item->no_sub;
+                       old_item->no_select = new_item->no_select;
+                       if (old_item->no_sub == TRUE && node->children) {
+                               debug_print("folder '%s' doesn't have "
+                                           "subfolders. removing...\n",
+                                           old_item->path);
+                               folder_item_remove_children(old_item);
+                       }
+               }
+
+               node = next;
+       }
+
        for (cur = item_list; cur != NULL; cur = cur->next) {
-               new_item = cur->data;
-               if (!strcmp(new_item->path, "INBOX")) {
-                       if (!folder->inbox) {
-                               new_item->stype = F_INBOX;
-                               item->folder->inbox = new_item;
-                       } else {
-                               folder_item_destroy(new_item);
-                               continue;
+               FolderItem *cur_item = FOLDER_ITEM(cur->data);
+               new_item = NULL;
+               for (node = item->node->children; node != NULL;
+                    node = node->next) {
+                       if (!strcmp2(FOLDER_ITEM(node->data)->path,
+                                    cur_item->path)) {
+                               new_item = FOLDER_ITEM(node->data);
+                               folder_item_destroy(cur_item);
+                               cur_item = NULL;
+                               break;
                        }
+               }
+               if (!new_item) {
+                       new_item = cur_item;
+                       debug_print("new folder '%s' found.\n", new_item->path);
+                       folder_item_append(item, new_item);
+               }
+
+               if (!strcmp(new_item->path, "INBOX")) {
+                       new_item->stype = F_INBOX;
+                       folder->inbox = new_item;
                } else if (!item->parent || item->stype == F_INBOX) {
                        gchar *base;
 
@@ -1173,11 +1364,13 @@ static gint imap_scan_tree_recursive(IMAPSession *session, FolderItem *item)
                                folder->trash = new_item;
                        }
                }
-               folder_item_append(item, new_item);
+
                if (new_item->no_sub == FALSE)
                        imap_scan_tree_recursive(session, new_item);
        }
 
+       g_slist_free(item_list);
+
        return IMAP_SUCCESS;
 }
 
@@ -1207,6 +1400,10 @@ static GSList *imap_parse_list(IMAPFolder *folder, IMAPSession *session,
                strretchomp(buf);
                if (buf[0] != '*' || buf[1] != ' ') {
                        log_print("IMAP4< %s\n", buf);
+                       if (sscanf(buf, "%*d %16s", buf) < 1 ||
+                           strcmp(buf, "OK") != 0)
+                               log_warning(_("error occurred while getting LIST.\n"));
+                               
                        break;
                }
                debug_print("IMAP4< %s\n", buf);
@@ -1257,7 +1454,7 @@ static GSList *imap_parse_list(IMAPFolder *folder, IMAPSession *session,
 
                item_list = g_slist_append(item_list, new_item);
 
-               debug_print("folder %s has been added.\n", loc_path);
+               debug_print("folder '%s' found.\n", loc_path);
                g_free(loc_path);
                g_free(loc_name);
        }
@@ -1267,7 +1464,7 @@ static GSList *imap_parse_list(IMAPFolder *folder, IMAPSession *session,
        return item_list;
 }
 
-gint imap_create_tree(Folder *folder)
+static gint imap_create_tree(Folder *folder)
 {
        g_return_val_if_fail(folder != NULL, -1);
        g_return_val_if_fail(folder->node != NULL, -1);
@@ -1380,7 +1577,7 @@ static gchar *imap_item_get_path(Folder *folder, FolderItem *item)
        return path;
 }
 
-FolderItem *imap_create_folder(Folder *folder, FolderItem *parent,
+static FolderItem *imap_create_folder(Folder *folder, FolderItem *parent,
                               const gchar *name)
 {
        gchar *dirpath, *imap_path;
@@ -1476,13 +1673,13 @@ FolderItem *imap_create_folder(Folder *folder, FolderItem *parent,
        return new_item;
 }
 
-gint imap_rename_folder(Folder *folder, FolderItem *item, const gchar *name)
+static gint imap_rename_folder(Folder *folder, FolderItem *item,
+                              const gchar *name)
 {
        gchar *dirpath;
        gchar *newpath;
        gchar *real_oldpath;
        gchar *real_newpath;
-       GNode *node;
        gchar *paths[2];
        gchar *old_cache_dir;
        gchar *new_cache_dir;
@@ -1537,11 +1734,9 @@ gint imap_rename_folder(Folder *folder, FolderItem *item, const gchar *name)
 
        old_cache_dir = folder_item_get_path(item);
 
-       node = g_node_find(item->folder->node, G_PRE_ORDER, G_TRAVERSE_ALL,
-                          item);
        paths[0] = g_strdup(item->path);
        paths[1] = newpath;
-       g_node_traverse(node, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
+       g_node_traverse(item->node, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
                        imap_rename_folder_func, paths);
 
        if (is_dir_exist(old_cache_dir)) {
@@ -1561,7 +1756,7 @@ gint imap_rename_folder(Folder *folder, FolderItem *item, const gchar *name)
        return 0;
 }
 
-gint imap_remove_folder(Folder *folder, FolderItem *item)
+static gint imap_remove_folder(Folder *folder, FolderItem *item)
 {
        gint ok;
        IMAPSession *session;
@@ -1612,6 +1807,7 @@ static GSList *imap_get_uncached_messages(IMAPSession *session,
        GSList *llast = NULL;
        GString *str;
        MsgInfo *msginfo;
+       GSList *seq_list, *cur;
        IMAPSet imapset;
 
        g_return_val_if_fail(session != NULL, NULL);
@@ -1619,8 +1815,10 @@ static GSList *imap_get_uncached_messages(IMAPSession *session,
        g_return_val_if_fail(item->folder != NULL, NULL);
        g_return_val_if_fail(FOLDER_CLASS(item->folder) == &imap_class, NULL);
 
-       imapset = numberlist_to_imapset(numlist);
-       while (imapset != NULL) {
+       seq_list = imap_get_seq_set_from_numlist(numlist);
+       for (cur = seq_list; cur != NULL; cur = g_slist_next(cur)) {
+               imapset = cur->data;
+
                if (imap_cmd_envelope(session, imapset)
                    != IMAP_SUCCESS) {
                        log_warning(_("can't get envelope\n"));
@@ -1673,8 +1871,8 @@ static GSList *imap_get_uncached_messages(IMAPSession *session,
                }
 
                g_string_free(str, TRUE);
-               imapset = numberlist_to_imapset(NULL);
        }
+       imap_seq_set_free(seq_list);
 
        return newlist;
 }
@@ -1882,14 +2080,15 @@ static IMAPNameSpace *imap_find_namespace_from_list(GList *ns_list,
 
        if (!path) path = "";
 
-       Xstrcat_a(tmp_path, path, "/", return NULL);
-
        for (; ns_list != NULL; ns_list = ns_list->next) {
                IMAPNameSpace *tmp_ns = ns_list->data;
 
+               Xstrcat_a(tmp_path, path, "/", return namespace);
                Xstrdup_a(name, tmp_ns->name, return namespace);
-               if (tmp_ns->separator && tmp_ns->separator != '/')
+               if (tmp_ns->separator && tmp_ns->separator != '/') {
+                       subst_char(tmp_path, tmp_ns->separator, '/');
                        subst_char(name, tmp_ns->separator, '/');
+               }
                if (strncmp(tmp_path, name, strlen(name)) == 0)
                        namespace = tmp_ns;
        }
@@ -1979,7 +2178,7 @@ static gchar *imap_parse_atom(SockInfo *sock, gchar *src,
 
                cur_pos = strchr_cpy(cur_pos + 1, '}', buf, sizeof(buf));
                len = atoi(buf);
-               g_return_val_if_fail(len > 0, cur_pos);
+               g_return_val_if_fail(len >= 0, cur_pos);
 
                g_string_truncate(str, 0);
                cur_pos = str->str;
@@ -2022,7 +2221,7 @@ static gchar *imap_get_header(SockInfo *sock, gchar *cur_pos, gchar **headers,
 
        cur_pos = strchr_cpy(cur_pos + 1, '}', buf, sizeof(buf));
        len = atoi(buf);
-       g_return_val_if_fail(len > 0, cur_pos);
+       g_return_val_if_fail(len >= 0, cur_pos);
 
        g_string_truncate(str, 0);
        cur_pos = str->str;
@@ -2198,7 +2397,7 @@ static gchar *imap_get_flag_str(IMAPFlags flags)
        if (IMAP_IS_DELETED(flags))     g_string_append(str, "\\Deleted ");
        if (IMAP_IS_DRAFT(flags))       g_string_append(str, "\\Draft");
 
-       if (str->str[str->len - 1] == ' ')
+       if (str->len > 0 && str->str[str->len - 1] == ' ')
                g_string_truncate(str, str->len - 1);
 
        ret = str->str;
@@ -2215,6 +2414,7 @@ static gint imap_set_message_flags(IMAPSession *session,
        gchar *cmd;
        gchar *flag_str;
        gint ok;
+       GSList *seq_list, *cur;
        IMAPSet imapset;
 
        flag_str = imap_get_flag_str(flags);
@@ -2222,11 +2422,13 @@ static gint imap_set_message_flags(IMAPSession *session,
                          flag_str, ")", NULL);
        g_free(flag_str);
 
-       imapset = numberlist_to_imapset(numlist);
-       while (imapset != NULL) {
+       seq_list = imap_get_seq_set_from_numlist(numlist);
+       for (cur = seq_list; cur != NULL; cur = g_slist_next(cur)) {
+               imapset = cur->data;
+
                ok = imap_cmd_store(session, imapset, cmd);
-               imapset = numberlist_to_imapset(NULL);
        }
+       imap_seq_set_free(seq_list);
        g_free(cmd);
 
        return ok;
@@ -2278,21 +2480,22 @@ static gint imap_status(IMAPSession *session, IMAPFolder *folder,
        gchar *real_path;
        gchar *real_path_;
        gint ok;
-       GPtrArray *argbuf;
+       GPtrArray *argbuf = NULL;
        gchar *str;
 
-       *messages = *recent = *uid_next = *uid_validity = *unseen = 0;
-
-       argbuf = g_ptr_array_new();
+       if (messages && recent && uid_next && uid_validity && unseen) {
+               *messages = *recent = *uid_next = *uid_validity = *unseen = 0;
+               argbuf = g_ptr_array_new();
+       }
 
        real_path = imap_get_real_path(folder, path);
        QUOTE_IF_REQUIRED(real_path_, real_path);
        imap_gen_send(session, "STATUS %s "
-                     "(MESSAGES RECENT UIDNEXT UIDVALIDITY UNSEEN)",
-                     real_path_);
+                         "(MESSAGES RECENT UIDNEXT UIDVALIDITY UNSEEN)",
+                         real_path_);
 
        ok = imap_cmd_ok(session, argbuf);
-       if (ok != IMAP_SUCCESS) THROW(ok);
+       if (ok != IMAP_SUCCESS || !argbuf) THROW(ok);
 
        str = search_array_str(argbuf, "STATUS");
        if (!str) THROW(IMAP_ERROR);
@@ -2326,14 +2529,33 @@ static gint imap_status(IMAPSession *session, IMAPFolder *folder,
 
 catch:
        g_free(real_path);
-       ptr_array_free_strings(argbuf);
-       g_ptr_array_free(argbuf, TRUE);
+       if (argbuf) {
+               ptr_array_free_strings(argbuf);
+               g_ptr_array_free(argbuf, TRUE);
+       }
 
        return ok;
 }
 
 #undef THROW
 
+static gboolean imap_has_capability(IMAPSession *session, const gchar *cap)
+{
+       gchar **p;
+       
+       for (p = session->capability; *p != NULL; ++p) {
+               if (!g_strcasecmp(*p, cap))
+                       return TRUE;
+       }
+
+       return FALSE;
+}
+
+static void imap_free_capabilities(IMAPSession *session)
+{
+       g_strfreev(session->capability);
+       session->capability = NULL;
+}
 
 /* low-level IMAP4rev1 commands */
 
@@ -2342,7 +2564,7 @@ static gint imap_cmd_authenticate(IMAPSession *session, const gchar *user,
 {
        gchar *auth_type;
        gint ok;
-       gchar *buf;
+       gchar *buf = NULL;
        gchar *challenge;
        gint challenge_len;
        gchar hexdigest[33];
@@ -2361,8 +2583,8 @@ static gint imap_cmd_authenticate(IMAPSession *session, const gchar *user,
        challenge = g_malloc(strlen(buf + 2) + 1);
        challenge_len = base64_decode(challenge, buf + 2, -1);
        challenge[challenge_len] = '\0';
-       log_print("IMAP< [Decoded: %s]\n", challenge);
        g_free(buf);
+       log_print("IMAP< [Decoded: %s]\n", challenge);
 
        md5_hex_hmac(hexdigest, challenge, challenge_len, pass, strlen(pass));
        g_free(challenge);
@@ -2405,117 +2627,6 @@ static gint imap_cmd_logout(IMAPSession *session)
        return imap_cmd_ok(session, NULL);
 }
 
-/* Send CAPABILITY, and examine the server's response to see whether this
- * connection is pre-authenticated or not and build a list of CAPABILITIES. */
-static gint imap_greeting(IMAPSession *session)
-{
-       gchar *capstr;
-       GPtrArray *argbuf;
-
-       imap_gen_send(session, "CAPABILITY");
-       
-       argbuf = g_ptr_array_new();
-
-       if (imap_cmd_ok(session, argbuf) != IMAP_SUCCESS ||
-           ((capstr = search_array_str(argbuf, "CAPABILITY ")) == NULL)) {
-               ptr_array_free_strings(argbuf);
-               g_ptr_array_free(argbuf, TRUE);
-               return -1;
-       }
-
-       session->authenticated = search_array_str(argbuf, "PREAUTH") != NULL;
-       
-       capstr += strlen("CAPABILITY ");
-
-       IMAP_SESSION(session)->capability = g_strsplit(capstr, " ", 0);
-       
-       ptr_array_free_strings(argbuf);
-       g_ptr_array_free(argbuf, TRUE);
-
-       return 0;
-}
-
-static gboolean imap_has_capability(IMAPSession *session, const gchar *cap)
-{
-       gchar **p;
-       
-       for (p = session->capability; *p != NULL; ++p)
-               if (g_strcasecmp(*p, cap) == 0)
-                       return TRUE;
-
-       return FALSE;
-}
-
-void imap_free_capabilities(IMAPSession *session)
-{
-       g_strfreev(session->capability);
-       session->capability = NULL;
-}
-
-static const IMAPSet numberlist_to_imapset(MsgNumberList *list)
-{
-       static GString *imapset = NULL;
-       static MsgNumberList *numlist, *elem;
-       guint first, last, next;
-
-       if (imapset == NULL)
-               imapset = g_string_sized_new(256);
-       else
-               g_string_truncate(imapset, 0);
-
-       if (list != NULL) {
-               g_slist_free(numlist);
-               numlist = g_slist_copy(list);
-               numlist = g_slist_sort(numlist, g_int_compare);
-       } else if (numlist == NULL) {
-               return NULL;
-       }
-
-       first = GPOINTER_TO_INT(numlist->data);
-       last = first;
-       for(elem = g_slist_next(numlist); elem != NULL; elem = g_slist_next(elem)) {
-               next = GPOINTER_TO_INT(elem->data);
-
-               if(next != (last + 1)) {
-                       if (imapset->len > 0)
-                               g_string_append(imapset, ",");
-                       if (first == last)
-                               g_string_sprintfa(imapset, "%d", first);
-                       else
-                               g_string_sprintfa(imapset, "%d:%d", first, last);
-
-                       if (imapset->len > IMAPCMDLIMIT) {
-                               last = 0;
-                               break;
-                       }
-
-                       first = next;
-               }
-               last = next;
-       }
-       if (last != 0) {
-               if (imapset->len > 0)
-                       g_string_append(imapset, ",");
-               if (first == last)
-                       g_string_sprintfa(imapset, "%d", first);
-               else
-                       g_string_sprintfa(imapset, "%d:%d", first, last);
-
-               g_slist_free(numlist);
-               numlist = NULL;
-       } else {
-               MsgNumberList *remaining;
-
-               remaining = elem->next;
-               remaining = g_slist_prepend(remaining, elem->data);
-               elem->next = NULL;
-               g_slist_free(numlist);
-               numlist = remaining;
-       }
-
-       return imapset->str;
-}
-
 static gint imap_cmd_noop(IMAPSession *session)
 {
        imap_gen_send(session, "NOOP");
@@ -2686,7 +2797,8 @@ static gint imap_cmd_delete(IMAPSession *session, const gchar *folder)
        return imap_cmd_ok(session, NULL);
 }
 
-static gint imap_cmd_search(IMAPSession *session, const gchar *criteria, GSList **list)
+static gint imap_cmd_search(IMAPSession *session, const gchar *criteria, 
+                           GSList **list)
 {
        gint ok;
        gchar *uidlist;
@@ -2725,10 +2837,11 @@ static gint imap_cmd_search(IMAPSession *session, const gchar *criteria, GSList
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, const gchar *filename)
+static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, 
+                          const gchar *filename)
 {
        gint ok;
-       gchar *buf;
+       gchar *buf = NULL;
        gchar *cur_pos;
        gchar size_str[32];
        glong size_num;
@@ -2737,14 +2850,12 @@ static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, const gchar *filen
 
        imap_gen_send(session, "UID FETCH %d BODY.PEEK[]", uid);
 
-       while ((ok = imap_gen_recv(session, &buf))
-              == IMAP_SUCCESS) {
+       while ((ok = imap_gen_recv(session, &buf)) == IMAP_SUCCESS) {
                if (buf[0] != '*' || buf[1] != ' ') {
                        g_free(buf);
                        return IMAP_ERROR;
                }
-               if (strstr(buf, "FETCH") != NULL)
-                       break;
+               if (strstr(buf, "FETCH") != NULL) break;
                g_free(buf);
        }
        if (ok != IMAP_SUCCESS) {
@@ -2752,29 +2863,28 @@ static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, const gchar *filen
                return ok;
        }
 
-       cur_pos = strchr(buf, '{');
-       if (cur_pos == NULL) {
-               g_free(buf);
-               return IMAP_ERROR;
+#define RETURN_ERROR_IF_FAIL(cond)     \
+       if (!(cond)) {                  \
+               g_free(buf);            \
+               return IMAP_ERROR;      \
        }
 
+       cur_pos = strchr(buf, '{');
+       RETURN_ERROR_IF_FAIL(cur_pos != NULL);
        cur_pos = strchr_cpy(cur_pos + 1, '}', size_str, sizeof(size_str));
-       if (cur_pos == NULL) {
-               g_free(buf);
-               return IMAP_ERROR;
-       }
+       RETURN_ERROR_IF_FAIL(cur_pos != NULL);
        size_num = atol(size_str);
-       g_return_val_if_fail(size_num > 0, IMAP_ERROR);
+       RETURN_ERROR_IF_FAIL(size_num >= 0);
 
-       if (*cur_pos != '\0') {
-               g_free(buf);
-               return IMAP_ERROR;
-       }
+       RETURN_ERROR_IF_FAIL(*cur_pos == '\0');
 
-       if (recv_bytes_write_to_file(SESSION(session)->sock, size_num, filename) != 0) {
-               g_free(buf);
+#undef RETURN_ERROR_IF_FAIL
+
+       g_free(buf);
+
+       if (recv_bytes_write_to_file(SESSION(session)->sock,
+                                    size_num, filename) != 0)
                return IMAP_ERROR;
-       }
 
        if (imap_gen_recv(session, &buf) != IMAP_SUCCESS) {
                g_free(buf);
@@ -2785,24 +2895,27 @@ static gint imap_cmd_fetch(IMAPSession *session, guint32 uid, const gchar *filen
                g_free(buf);
                return IMAP_ERROR;
        }
-
        g_free(buf);
+
        ok = imap_cmd_ok(session, NULL);
 
        return ok;
 }
 
 static gint imap_cmd_append(IMAPSession *session, const gchar *destfolder,
-                           const gchar *file, IMAPFlags flags, gint32 *new_uid)
+                           const gchar *file, IMAPFlags flags, 
+                           guint32 *new_uid)
 {
        gint ok;
-       gint size, newuid;
+       gint size;
        gchar *destfolder_;
        gchar *flag_str;
-       gchar buf[BUFFSIZE], *imapbuf;
+       guint32 new_uid_;
+       gchar *ret = NULL;
+       gchar buf[BUFFSIZE];
        FILE *fp;
-       GPtrArray *reply;
-       gchar *okmsginfo;
+       GPtrArray *argbuf;
+       gchar *resp_str;
 
        g_return_val_if_fail(file != NULL, IMAP_ERROR);
 
@@ -2817,14 +2930,14 @@ static gint imap_cmd_append(IMAPSession *session, const gchar *destfolder,
                      destfolder_, flag_str, size);
        g_free(flag_str);
 
-       ok = imap_gen_recv(session, &imapbuf);
-       if (ok != IMAP_SUCCESS || imapbuf[0] != '+' || imapbuf[1] != ' ') {
+       ok = imap_gen_recv(session, &ret);
+       if (ok != IMAP_SUCCESS || ret[0] != '+' || ret[1] != ' ') {
                log_warning(_("can't append %s to %s\n"), file, destfolder_);
-               g_free(imapbuf);
+               g_free(ret);
                fclose(fp);
                return IMAP_ERROR;
        }
-       g_free(imapbuf);
+       g_free(ret);
 
        log_print("IMAP4> %s\n", _("(sending file...)"));
 
@@ -2846,57 +2959,112 @@ static gint imap_cmd_append(IMAPSession *session, const gchar *destfolder,
 
        fclose(fp);
 
-       reply = g_ptr_array_new();
+       if (new_uid != NULL)
+               *new_uid = 0;
+
+       if (new_uid != NULL && session->uidplus) {
+               argbuf = g_ptr_array_new();
+
+               ok = imap_cmd_ok(session, argbuf);
+               if ((ok == IMAP_SUCCESS) && (argbuf->len > 0)) {
+                       resp_str = g_ptr_array_index(argbuf, argbuf->len - 1);
+                       if (resp_str &&
+                           sscanf(resp_str, "%*u OK [APPENDUID %*u %u]",
+                                  &new_uid_) == 1) {
+                               *new_uid = new_uid_;
+                       }
+               }
+
+               ptr_array_free_strings(argbuf);
+               g_ptr_array_free(argbuf, TRUE);
+       } else
+               ok = imap_cmd_ok(session, NULL);
 
-       *new_uid = 0;
-       ok = imap_cmd_ok(session, reply);
        if (ok != IMAP_SUCCESS)
-               log_warning(_("can't append message to %s\n"), destfolder_);
-       else if (
-           (new_uid != NULL) && 
-           (imap_has_capability(session, "UIDPLUS") && reply->len > 0) &&
-           ((okmsginfo = g_ptr_array_index(reply, reply->len - 1)) != NULL) &&
-           (sscanf(okmsginfo, "%*u OK [APPENDUID %*u %u]", &newuid) == 1)) {
-               *new_uid = newuid;
-       }
+               log_warning(_("can't append message to %s\n"),
+                           destfolder_);
 
-       ptr_array_free_strings(reply);
-       g_ptr_array_free(reply, TRUE);
        return ok;
 }
 
+static MsgNumberList *imapset_to_numlist(IMAPSet imapset)
+{
+       gchar **ranges, **range;
+       guint32 low, high;
+       MsgNumberList *uids = NULL;
+       
+       ranges = g_strsplit(imapset, ",", 0);
+       for (range = ranges; *range != NULL; range++) {
+               printf("%s\n", *range);
+               if(sscanf(*range, "%u:%u", &low, &high) == 1)
+                       uids = g_slist_prepend(uids, GINT_TO_POINTER(low));
+               else {
+                       int i;
+                       for (i = low; i <= high; i++)
+                               uids = g_slist_prepend(uids, GINT_TO_POINTER(i));
+               }
+       }
+       uids = g_slist_reverse(uids);
+       g_strfreev(ranges);
+
+       return uids;
+}
 
-static gint imap_cmd_copy(IMAPSession * session,
-                         gint32 msgnum,
-                         const gchar * destfolder, gint32 * new_uid)
+static gint imap_cmd_copy(IMAPSession *session, const gchar *seq_set,
+                         const gchar *destfolder, GRelation *uid_mapping)
 {
        gint ok;
-       gint32 olduid, newuid;
-       gchar *okmsginfo;
        gchar *destfolder_;
-       GPtrArray *reply;
-
-       g_return_val_if_fail(destfolder != NULL, IMAP_ERROR);
+       
        g_return_val_if_fail(session != NULL, IMAP_ERROR);
-       g_return_val_if_fail(new_uid != NULL, IMAP_ERROR);
+       g_return_val_if_fail(seq_set != NULL, IMAP_ERROR);
+       g_return_val_if_fail(destfolder != NULL, IMAP_ERROR);
 
        QUOTE_IF_REQUIRED(destfolder_, destfolder);
-       imap_gen_send(session, "UID COPY %d %s", msgnum, destfolder_);
+       imap_gen_send(session, "UID COPY %s %s", seq_set, destfolder_);
+
+       if (uid_mapping != NULL && session->uidplus) {
+               GPtrArray *reply;               
+               gchar *resp_str = NULL, *olduids_str, *newuids_str;
+               MsgNumberList *olduids, *old_cur, *newuids, *new_cur;
+
+               reply = g_ptr_array_new();
+               ok = imap_cmd_ok(session, reply);
+               if ((ok == IMAP_SUCCESS) && (reply->len > 0)) {
+                       resp_str = g_ptr_array_index(reply, reply->len - 1);
+                       if (resp_str) {
+                               olduids_str = g_new0(gchar, strlen(resp_str));
+                               newuids_str = g_new0(gchar, strlen(resp_str));
+                               if (sscanf(resp_str, "%*s OK [COPYUID %*u %[0-9,:] %[0-9,:]]",
+                                          olduids_str, newuids_str) == 2) {
+                                       olduids = imapset_to_numlist(olduids_str);
+                                       newuids = imapset_to_numlist(newuids_str);
+
+                                       old_cur = olduids;
+                                       new_cur = newuids;
+                                       while(old_cur != NULL && new_cur != NULL) {
+                                               g_relation_insert(uid_mapping, 
+                                                                 GPOINTER_TO_INT(old_cur->data),
+                                                                 GPOINTER_TO_INT(new_cur->data));
+                                               old_cur = g_slist_next(old_cur);
+                                               new_cur = g_slist_next(new_cur);
+                                       }
 
-       reply = g_ptr_array_new();
+                                       g_slist_free(olduids);
+                                       g_slist_free(newuids);
+                               }
+                               g_free(olduids_str);
+                               g_free(newuids_str);
+                       }
+               }
+               ptr_array_free_strings(reply);
+               g_ptr_array_free(reply, TRUE);
+       } else
+               ok = imap_cmd_ok(session, NULL);
 
-       *new_uid = 0;
-       ok = imap_cmd_ok(session, reply);
        if (ok != IMAP_SUCCESS)
-               log_warning(_("can't copy %d to %s\n"), msgnum, destfolder_);
-       else if (imap_has_capability(session, "UIDPLUS") && reply->len > 0)
-               if ((okmsginfo = g_ptr_array_index(reply, reply->len - 1)) != NULL &&
-                   sscanf(okmsginfo, "%*u OK [COPYUID %*u %u %u]", &olduid, &newuid) == 2 &&
-                   olduid == msgnum)
-                       *new_uid = newuid;
-
-       ptr_array_free_strings(reply);
-       g_ptr_array_free(reply, TRUE);
+               log_warning(_("can't copy %s to %s\n"), seq_set, destfolder_);
+
        return ok;
 }
 
@@ -2937,28 +3105,30 @@ gint imap_cmd_envelope(IMAPSession *session, IMAPSet set)
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_store(IMAPSession *session, IMAPSet set,
+static gint imap_cmd_store(IMAPSession *session, IMAPSet seq_set,
                           gchar *sub_cmd)
 {
        gint ok;
 
-       imap_gen_send(session, "UID STORE %s %s",
-                         set, sub_cmd);
+       imap_gen_send(session, "UID STORE %s %s", seq_set, sub_cmd);
 
        if ((ok = imap_cmd_ok(session, NULL)) != IMAP_SUCCESS) {
                log_warning(_("error while imap command: STORE %s %s\n"),
-                           set, sub_cmd);
+                           seq_set, sub_cmd);
                return ok;
        }
 
        return IMAP_SUCCESS;
 }
 
-static gint imap_cmd_expunge(IMAPSession *session)
+static gint imap_cmd_expunge(IMAPSession *session, IMAPSet seq_set)
 {
        gint ok;
 
-       imap_gen_send(session, "EXPUNGE");
+       if (seq_set && session->uidplus)
+               imap_gen_send(session, "UID EXPUNGE %s", seq_set);
+       else    
+               imap_gen_send(session, "EXPUNGE");
        if ((ok = imap_cmd_ok(session, NULL)) != IMAP_SUCCESS) {
                log_warning(_("error while imap command: EXPUNGE\n"));
                return ok;
@@ -3051,14 +3221,14 @@ static void imap_gen_send(IMAPSession *session, const gchar *format, ...)
        g_free(buf);
 }
 
-static gint imap_gen_recv(IMAPSession *session, gchar **buf)
+static gint imap_gen_recv(IMAPSession *session, gchar **ret)
 {
-       if ((*buf = sock_getline(SESSION(session)->sock)) == NULL)
+       if ((*ret = sock_getline(SESSION(session)->sock)) == NULL)
                return IMAP_SOCKET;
 
-       strretchomp(*buf);
+       strretchomp(*ret);
 
-       log_print("IMAP4< %s\n", *buf);
+       log_print("IMAP4< %s\n", *ret);
 
        return IMAP_SUCCESS;
 }
@@ -3376,6 +3546,84 @@ static gchar *imap_locale_to_modified_utf7(const gchar *from)
 #endif /* !HAVE_ICONV */
 }
 
+static GSList *imap_get_seq_set_from_numlist(MsgNumberList *numlist)
+{
+       GString *str;
+       GSList *sorted_list, *cur;
+       guint first, last, next;
+       gchar *ret_str;
+       GSList *ret_list = NULL;
+
+       if (numlist == NULL)
+               return NULL;
+
+       str = g_string_sized_new(256);
+
+       sorted_list = g_slist_copy(numlist);
+       sorted_list = g_slist_sort(sorted_list, g_int_compare);
+
+       first = GPOINTER_TO_INT(sorted_list->data);
+
+       for (cur = sorted_list; cur != NULL; cur = g_slist_next(cur)) {
+               last = GPOINTER_TO_INT(cur->data);
+               if (cur->next)
+                       next = GPOINTER_TO_INT(cur->next->data);
+               else
+                       next = 0;
+
+               if (last + 1 != next || next == 0) {
+                       if (str->len > 0)
+                               g_string_append_c(str, ',');
+                       if (first == last)
+                               g_string_sprintfa(str, "%u", first);
+                       else
+                               g_string_sprintfa(str, "%u:%u", first, last);
+
+                       first = next;
+
+                       if (str->len > IMAP_CMD_LIMIT) {
+                               ret_str = g_strdup(str->str);
+                               ret_list = g_slist_append(ret_list, ret_str);
+                               g_string_truncate(str, 0);
+                       }
+               }
+       }
+
+       if (str->len > 0) {
+               ret_str = g_strdup(str->str);
+               ret_list = g_slist_append(ret_list, ret_str);
+       }
+
+       g_slist_free(sorted_list);
+       g_string_free(str, TRUE);
+
+       return ret_list;
+}
+
+static GSList *imap_get_seq_set_from_msglist(MsgInfoList *msglist)
+{
+       MsgNumberList *numlist = NULL;
+       MsgInfoList *cur;
+       GSList *seq_list;
+
+       for (cur = msglist; cur != NULL; cur = g_slist_next(cur)) {
+               MsgInfo *msginfo = (MsgInfo *) cur->data;
+
+               numlist = g_slist_append(numlist, GINT_TO_POINTER(msginfo->msgnum));
+       }
+       seq_list = imap_get_seq_set_from_numlist(numlist);
+       g_slist_free(numlist);
+
+       return seq_list;
+}
+
+static void imap_seq_set_free(GSList *seq_list)
+{
+       slist_free_strings(seq_list);
+       g_slist_free(seq_list);
+}
+
+
 static gboolean imap_rename_folder_func(GNode *node, gpointer data)
 {
        FolderItem *item = node->data;
@@ -3480,11 +3728,11 @@ static gint get_list_of_uids(Folder *folder, IMAPFolderItem *item, GSList **msgn
        return nummsgs;
 }
 
-gint imap_get_num_list(Folder *folder, FolderItem *_item, GSList **msgnum_list)
+gint imap_get_num_list(Folder *folder, FolderItem *_item, GSList **msgnum_list, gboolean *old_uids_valid)
 {
        IMAPFolderItem *item = (IMAPFolderItem *)_item;
        IMAPSession *session;
-       gint ok, nummsgs = 0, exists, recent, unseen, uid_val, uid_next;
+       gint ok, nummsgs = 0, exists, recent, uid_val, uid_next, unseen;
        GSList *uidlist;
        gchar *dir;
        gboolean selected_folder;
@@ -3505,13 +3753,33 @@ gint imap_get_num_list(Folder *folder, FolderItem *_item, GSList **msgnum_list)
                if (ok != IMAP_SUCCESS)
                        return -1;
                exists = session->exists;
+
+               *old_uids_valid = TRUE;
        } else {
                ok = imap_status(session, IMAP_FOLDER(folder), item->item.path,
                                 &exists, &recent, &uid_next, &uid_val, &unseen);
                if (ok != IMAP_SUCCESS)
                        return -1;
+
+               if(item->item.mtime == uid_val)
+                       *old_uids_valid = TRUE;
+               else {
+                       *old_uids_valid = FALSE;
+
+                       debug_print("Freeing imap uid cache\n");
+                       item->lastuid = 0;
+                       g_slist_free(item->uid_list);
+                       item->uid_list = NULL;
+               
+                       item->item.mtime = uid_val;
+
+                       imap_delete_all_cached_messages((FolderItem *)item);
+               }
        }
 
+       if (!selected_folder)
+               item->uid_next = uid_next;
+
        /* If old uid_next matches new uid_next we can be sure no message
           was added to the folder */
        if (( selected_folder && !session->folder_content_changed) ||
@@ -3533,8 +3801,6 @@ gint imap_get_num_list(Folder *folder, FolderItem *_item, GSList **msgnum_list)
                        item->uid_list = NULL;
                }
        }
-       if (!selected_folder)
-               item->uid_next = uid_next;
 
        if (exists == 0) {
                *msgnum_list = NULL;
@@ -3677,37 +3943,43 @@ MsgInfo *imap_get_msginfo(Folder *folder, FolderItem *item, gint uid)
        return msginfo;
 }
 
-gboolean imap_check_msgnum_validity(Folder *folder, FolderItem *_item)
+gboolean imap_scan_required(Folder *folder, FolderItem *_item)
 {
        IMAPSession *session;
        IMAPFolderItem *item = (IMAPFolderItem *)_item;
        gint ok, exists = 0, recent = 0, unseen = 0;
-       guint32 uid_next, uid_validity = 0;
+       guint32 uid_next, uid_val = 0;
+       gboolean selected_folder;
        
        g_return_val_if_fail(folder != NULL, FALSE);
        g_return_val_if_fail(item != NULL, FALSE);
        g_return_val_if_fail(item->item.folder != NULL, FALSE);
        g_return_val_if_fail(FOLDER_CLASS(item->item.folder) == &imap_class, FALSE);
 
+       if (item->item.path == NULL)
+               return FALSE;
+
        session = imap_session_get(folder);
        g_return_val_if_fail(session != NULL, FALSE);
 
-       ok = imap_status(session, IMAP_FOLDER(folder), item->item.path,
-                        &exists, &recent, &uid_next, &uid_validity, &unseen);
-       if (ok != IMAP_SUCCESS)
-               return FALSE;
-
-       if(item->item.mtime == uid_validity)
-               return TRUE;
+       selected_folder = (session->mbox != NULL) &&
+                         (!strcmp(session->mbox, item->item.path));
+       if (selected_folder) {
+               ok = imap_cmd_noop(session);
+               if (ok != IMAP_SUCCESS)
+                       return FALSE;
 
-       debug_print("Freeing imap uid cache\n");
-       item->lastuid = 0;
-       g_slist_free(item->uid_list);
-       item->uid_list = NULL;
-               
-       item->item.mtime = uid_validity;
+               if (session->folder_content_changed)
+                       return TRUE;
+       } else {
+               ok = imap_status(session, IMAP_FOLDER(folder), item->item.path,
+                                &exists, &recent, &uid_next, &uid_val, &unseen);
+               if (ok != IMAP_SUCCESS)
+                       return FALSE;
 
-       imap_delete_all_cached_messages((FolderItem *)item);
+               if ((uid_next != item->uid_next) || (exists < item->item.total_msgs))
+                       return TRUE;
+       }
 
        return FALSE;
 }