[evolution-kolab] KolabMailAccess: do online folder existence check when deleting

[Christian Hilberg <chilberg src gnome org>]

commit 42a11fe44d2fb51575feea46f0e0c7cad26b1007
Author: Christian Hilberg <hilberg kernelconcepts de>
Date:   Wed Sep 19 15:02:56 2012 +0200

    KolabMailAccess: do online folder existence check when deleting
    
    * we're requiring online operational mode for folder deletion,
      so we can just ask the server for folder existence
    * this enables us to become folder type agnostic in the delete()
      operation, which we need to be in the collection backend
      (which handles create/delete for folders (sources))

 src/libekolab/kolab-mail-access.c |   70 ++++++++++++++++++++++++++++++++-----
 1 files changed, 61 insertions(+), 9 deletions(-)
---
diff --git a/src/libekolab/kolab-mail-access.c b/src/libekolab/kolab-mail-access.c
index a1853ec..8a54173 100644
--- a/src/libekolab/kolab-mail-access.c
+++ b/src/libekolab/kolab-mail-access.c
@@ -2961,7 +2961,7 @@ kolab_mail_access_query_sources (KolabMailAccess *self,
  * Returns: a #GList of pointers to newly allocated
  *          #KolabFolderDescriptor objects. Free the
  *          list with kolab_util_folder_descriptor_glist_free()
- *          once you're done using the list. The list
+ *          once you're done using it. The list
  *          returned may be NULL without that being an
  *          error (check @err separately)
  *
@@ -3154,7 +3154,9 @@ kolab_mail_access_delete_source (KolabMailAccess *self,
                                  GError **err)
 {
 	KolabMailAccessPrivate *priv = NULL;
-	/* gboolean exists = FALSE; */
+	GList *folders_desc = NULL;
+	GList *folders_desc_ptr = NULL;
+	gboolean exists = FALSE;
 	gboolean ok = TRUE;
 	GError *tmp_err = NULL;
 
@@ -3167,22 +3169,72 @@ kolab_mail_access_delete_source (KolabMailAccess *self,
 
 	g_mutex_lock (&(priv->big_lock));
 
-	if (priv->state->opmode <= KOLAB_MAIL_ACCESS_OPMODE_CONFIGURED)
+	if (priv->state->opmode <= KOLAB_MAIL_ACCESS_OPMODE_OFFLINE) {
+		g_set_error (&tmp_err,
+		             KOLAB_BACKEND_ERROR,
+		             KOLAB_BACKEND_ERROR_STATE_WRONG_FOR_OP,
+		             _("You must be working online to complete this operation"));
+		ok = FALSE;
 		goto exit;
-#if 0
+	}
 
 	/* check whether folder exists */
-	exists = kolab_mail_info_db_exists_foldername (priv->infodb,
-	                                               sourcename,
-	                                               &tmp_err);
+
+	/* We are in online mode, so we can directly query the folder
+	 * situation from the server. Moreover, our local InfoDb will
+	 * be blind w.r.t. folders not matching the currently-configured
+	 * folder context (mail, calendar, contacts). We need the folder
+	 * delete operation to be foldertype-agnostic since the collection
+	 * backend needs to be able to delete all (PIM) types of folders
+	 * without prior reconfiguring of the folder context it is in.
+	 * So we online-query the list of folders (and their types) from
+	 * the server and check whether we find the to-be-deleted folder
+	 * there
+	 */
+	folders_desc = kolab_mail_imap_client_query_folder_info_online (priv->client,
+	                                                                cancellable,
+	                                                                &tmp_err);
 	if (tmp_err != NULL) {
 		ok = FALSE;
 		goto exit;
 	}
 
-	if (! exists)
+	folders_desc_ptr = folders_desc;
+	while (folders_desc_ptr != NULL) {
+		KolabFolderDescriptor *desc = (KolabFolderDescriptor *) folders_desc_ptr->data;
+		exists = g_str_equal (desc->name, sourcename);
+		if (exists)
+			break;
+		folders_desc_ptr = g_list_next (folders_desc_ptr);
+	}
+
+	kolab_util_folder_descriptor_glist_free (folders_desc);
+	
+	if (! exists) {
+		/* We assume here that if a folder has been deleted,
+		 * the folder annotation has been deleted as well
+		 * (either by the client deleting the folder or by
+		 * a well-bahaving server, which deletes the folder
+		 * metadata once the folder is deleted, as per RFC
+		 * recommendation), We could check for existing folder
+		 * metadata here and delete it here, but it needs
+		 * second thought whether we should even try that.
+		 *
+		 * The locally cached data will no longer be accessed
+		 * since the backend for that folder will be removed
+		 * after successful deletion of the server folder, and
+		 * the ESource (config data) for the folder will be
+		 * deleted. The E-D-S cache reaper will then kill the
+		 * orphaned cache directory and we're done. This of
+		 * course means that if we still have objects in the
+		 * offline cache for this folder, they will silently
+		 * be dropped along with the rest of the folder (we
+		 * would need a way to differentiate between "delete
+		 * locally only" and "delete completely", which EClients
+		 * currently don't do)
+		 */
 		goto exit;
-#endif
+	}
 
 	/* delete folder */
 	ok = mail_access_local_delete (self,