use CamelExceptions for run-time errors, not incorrect code. Don't bother

	* camel-folder.c: use CamelExceptions for run-time errors, not
	incorrect code. Don't bother validating that an object exists from
	inside one of its methods, since you couldn't have gotten there if
	it didn't. Fix some code style bugs.

svn path=/trunk/; revision=1918

1 files changed, 138 insertions, 731 deletions

diff --git a/camel/camel-folder.c b/camel/camel-folder.c
index ae102451ec..b516216381 100644
--- a/camel/camel-folder.c
+++ b/camel/camel-folder.c
@@ -33,7 +33,7 @@
 static GtkObjectClass *parent_class=NULL;
 
 /* Returns the class for a CamelFolder */
-#define CF_CLASS(so) CAMEL_FOLDER_CLASS (GTK_OBJECT(so)->klass)
+#define CF_CLASS(so) CAMEL_FOLDER_CLASS (GTK_OBJECT (so)->klass)
 
 
 
@@ -73,29 +73,34 @@ static void _set_name (CamelFolder *folder,
 static const gchar *_get_name (CamelFolder *folder, 
 			       CamelException *ex);
 static const gchar *_get_full_name (CamelFolder *folder, CamelException *ex);
-/*  static void _set_full_name (CamelFolder *folder, const gchar *name); */
 
 
-static gboolean _can_hold_folders  (CamelFolder *folder, CamelException *ex);
-static gboolean _can_hold_messages (CamelFolder *folder, CamelException *ex);
+static gboolean _can_hold_folders  (CamelFolder *folder);
+static gboolean _can_hold_messages (CamelFolder *folder);
 static gboolean _exists  (CamelFolder  *folder, CamelException *ex);
-static gboolean _is_open (CamelFolder *folder, CamelException *ex);
-static const GList *_list_permanent_flags (CamelFolder *folder, CamelException *ex);
-static CamelFolderOpenMode _get_mode      (CamelFolder *folder, CamelException *ex);
+static gboolean _is_open (CamelFolder *folder);
+static const GList *_list_permanent_flags (CamelFolder *folder,
+					   CamelException *ex);
+static CamelFolderOpenMode _get_mode      (CamelFolder *folder,
+					   CamelException *ex);
 
 
 static gboolean _create (CamelFolder *folder, CamelException *ex);
-static gboolean _delete (CamelFolder *folder, gboolean recurse, CamelException *ex);
+static gboolean _delete (CamelFolder *folder, gboolean recurse,
+			 CamelException *ex);
 
 
 static GList *_list_subfolders  (CamelFolder *folder, CamelException *ex);
 static CamelFolder *_get_subfolder (CamelFolder *folder, 
-				 const gchar *folder_name, CamelException *ex);
-static CamelFolder *_get_parent_folder (CamelFolder *folder, CamelException *ex);
-static CamelStore * _get_parent_store  (CamelFolder *folder, CamelException *ex);
+				    const gchar *folder_name,
+				    CamelException *ex);
+static CamelFolder *_get_parent_folder (CamelFolder *folder,
+					CamelException *ex);
+static CamelStore * _get_parent_store  (CamelFolder *folder,
+					CamelException *ex);
 
 
-static gboolean _has_message_number_capability (CamelFolder *folder, CamelException *ex);
+static gboolean _has_message_number_capability (CamelFolder *folder);
 static CamelMimeMessage *_get_message_by_number (CamelFolder *folder, 
 						 gint number, 
 						 CamelException *ex);
@@ -116,7 +121,8 @@ static void _copy_message_to (CamelFolder *folder,
 			      CamelException *ex);
 
 
-static GList            *_get_uid_list       (CamelFolder *folder, CamelException *ex);
+static GList            *_get_uid_list       (CamelFolder *folder,
+					      CamelException *ex);
 static const gchar      *_get_message_uid    (CamelFolder *folder, 
 					      CamelMimeMessage *message, 
 					      CamelException *ex);
@@ -216,6 +222,9 @@ _finalize (GtkObject *object)
 	g_free (camel_folder->full_name);
 	g_free (camel_folder->permanent_flags);
 
+	if (camel_folder->parent_store)
+		gtk_object_unref (GTK_OBJECT (camel_folder->parent_store));
+
 	GTK_OBJECT_CLASS (parent_class)->finalize (object);
 	CAMEL_LOG_FULL_DEBUG ("Leaving CamelFolder::finalize\n");
 }
@@ -232,26 +241,9 @@ static void
 _init_with_store (CamelFolder *folder, CamelStore *parent_store, CamelException *ex)
 {
 	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
-	if (!parent_store) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_INVALID_PARAM,
-				     "parent_store parameter is NULL");
-		return;
-	}
-	
-	if (folder->parent_store) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "folder already has a parent store");
-		return;
-	}
+	g_assert (folder != NULL);
+	g_assert (parent_store != NULL);
+	g_assert (folder->parent_store == NULL);
 	
 	folder->parent_store = parent_store;
 	gtk_object_ref (GTK_OBJECT (parent_store));
@@ -271,13 +263,6 @@ _open (CamelFolder *folder,
        CamelFolderOpenMode mode, 
        CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
   	folder->open_state = FOLDER_OPEN;
   	folder->open_mode = mode;
 }
@@ -299,13 +284,8 @@ camel_folder_open (CamelFolder *folder,
 		   CamelFolderOpenMode mode, 
 		   CamelException *ex)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-	CF_CLASS(folder)->open (folder, mode, ex);
+	g_assert (folder != NULL);
+	CF_CLASS (folder)->open (folder, mode, ex);
 }
 
 
@@ -347,13 +327,8 @@ camel_folder_open_async (CamelFolder *folder,
 			 gpointer user_data, 
 			 CamelException *ex)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-	CF_CLASS(folder)->open_async (folder, mode, callback, user_data, ex);
+	g_assert (folder != NULL);
+	CF_CLASS (folder)->open_async (folder, mode, callback, user_data, ex);
 }
 
 
@@ -366,12 +341,6 @@ _close (CamelFolder *folder,
 	gboolean expunge, 
 	CamelException *ex)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
 	folder->open_state = FOLDER_CLOSE;
 }
 
@@ -390,13 +359,8 @@ camel_folder_close (CamelFolder *folder,
 		    gboolean expunge, 
 		    CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-	CF_CLASS(folder)->close (folder, expunge, ex);
+	g_assert (folder != NULL);
+	CF_CLASS (folder)->close (folder, expunge, ex);
 }
 
 
@@ -412,12 +376,6 @@ _close_async (CamelFolder *folder,
 	      gpointer user_data, 
 	      CamelException *ex)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
 	CAMEL_LOG_WARNING ("Calling CamelFolder::close_async directly. "
 			   "Should be overloaded\n");
 }
@@ -443,13 +401,9 @@ camel_folder_close_async (CamelFolder *folder,
 			  gpointer user_data, 
 			  CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-	CF_CLASS(folder)->close_async (folder, expunge, callback, user_data, ex);
+	g_assert (folder != NULL);
+	CF_CLASS (folder)->close_async (folder, expunge, callback,
+					user_data, ex);
 }
 
 
@@ -465,13 +419,10 @@ _set_name (CamelFolder *folder,
 	gchar *full_name;
 	const gchar *parent_full_name;
 	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
+	g_assert (folder->parent_store != NULL);
+	g_assert (name != NULL);
+	g_assert (!camel_folder_is_open (folder));
+			
 	/* if the folder already has a name, free it */	
 	g_free (folder->name);
 	g_free (folder->full_name);
@@ -481,48 +432,25 @@ _set_name (CamelFolder *folder,
 	folder->name = NULL;
 	folder->full_name = NULL;
 
-	if (!name) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_INVALID_PARAM,
-				     "name parameter is NULL");
-		return;
-	}	
-
-	CAMEL_LOG_FULL_DEBUG ("CamelFolder::set_name, folder name is %s\n", name);
+	CAMEL_LOG_FULL_DEBUG ("CamelFolder::set_name, folder name is %s\n",
+			      name);
 
-	
-	if (!folder->parent_store) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "folder has no parent store");
-		return;
-	}
-
-	/* the set_name method is valid only on 
-	   close folders */
-
-	if (camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::set_name is valid only on closed folders");
-		return;		
-	}
-			
 	separator = camel_store_get_separator (folder->parent_store, ex);
 	if (camel_exception_get_id (ex)) return;
 
-	camel_exception_clear (ex);
 	if (folder->parent_folder) {
-		parent_full_name = camel_folder_get_full_name (folder->parent_folder, ex);
+		parent_full_name =
+			camel_folder_get_full_name (folder->parent_folder, ex);
 		if (camel_exception_get_id (ex)) return;
 		
-		full_name = g_strdup_printf ("%s%c%s", parent_full_name, separator, name);		
+		full_name = g_strdup_printf ("%s%c%s", parent_full_name,
+					     separator, name);		
 	} else {
 		full_name = g_strdup_printf ("%c%s", separator, name);
 	}
 
-	CAMEL_LOG_FULL_DEBUG ("CamelFolder::set_name, folder full name set to %s\n", full_name);
+	CAMEL_LOG_FULL_DEBUG ("CamelFolder::set_name, folder full name "
+			      "set to %s\n", full_name);
 	folder->name = g_strdup (name);
 	folder->full_name = full_name;
 	
@@ -536,72 +464,18 @@ _set_name (CamelFolder *folder,
  * @ex: exception object
  **/
 void
-camel_folder_set_name (CamelFolder *folder, const gchar *name, CamelException *ex)
+camel_folder_set_name (CamelFolder *folder, const gchar *name,
+		       CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-	}
-
-	CF_CLASS(folder)->set_name (folder, name, ex);
-}
-
-
-
-
-
-/* not used for the moment, I don't know if it it is
-   a good idea or not to use it */
-#if 0
-static void
-_set_full_name (CamelFolder *folder, const gchar *name, CamelException *ex)
-{
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-	g_free(folder->full_name);
-	folder->full_name = g_strdup (name);
+	g_assert (folder != NULL);
+	CF_CLASS (folder)->set_name (folder, name, ex);
 }
 
 
-/**
- * camel_folder_set_full_name:set the (full) name of the folder
- * @folder: folder
- * @name: new name of the folder
- * 
- * set the name of the folder. 
- * 
- **/
-void 
-camel_folder_set_full_name (CamelFolder *folder, const gchar *name, CamelException *ex)
-{
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
-	CF_CLASS(folder)->set_full_name (folder, name, ex);
-}
-#endif
-
-
-
 
 static const gchar *
 _get_name (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
 	return folder->name;
 }
 
@@ -618,14 +492,8 @@ _get_name (CamelFolder *folder, CamelException *ex)
 const gchar *
 camel_folder_get_name (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	return CF_CLASS(folder)->get_name (folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->get_name (folder, ex);
 }
 
 
@@ -633,13 +501,6 @@ camel_folder_get_name (CamelFolder *folder, CamelException *ex)
 static const gchar *
 _get_full_name (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	return folder->full_name;
 }
 
@@ -654,14 +515,8 @@ _get_full_name (CamelFolder *folder, CamelException *ex)
 const gchar *
 camel_folder_get_full_name (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	return CF_CLASS(folder)->get_full_name (folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->get_full_name (folder, ex);
 }
 
 
@@ -675,15 +530,8 @@ camel_folder_get_full_name (CamelFolder *folder, CamelException *ex)
  * Return value: 
  **/
 static gboolean
-_can_hold_folders (CamelFolder *folder, CamelException *ex)
+_can_hold_folders (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
 	return folder->can_hold_folders;
 }
 
@@ -701,15 +549,8 @@ _can_hold_folders (CamelFolder *folder, CamelException *ex)
  * Return value: true if it can contain messages false otherwise
  **/
 static gboolean
-_can_hold_messages (CamelFolder *folder, CamelException *ex)
+_can_hold_messages (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
 	return folder->can_hold_messages;
 }
 
@@ -718,13 +559,6 @@ _can_hold_messages (CamelFolder *folder, CamelException *ex)
 static gboolean
 _exists (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
 	return FALSE;
 }
 
@@ -742,14 +576,8 @@ _exists (CamelFolder *folder, CamelException *ex)
 gboolean
 camel_folder_exists (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-	
-	return (CF_CLASS(folder)->exists (folder, ex));
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->exists (folder, ex);
 }
 
 
@@ -764,16 +592,9 @@ camel_folder_exists (CamelFolder *folder, CamelException *ex)
  * Return value: true if the folder exists, false otherwise
  **/
 static gboolean
-_is_open (CamelFolder *folder, CamelException *ex)
+_is_open (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	return (folder->open_state == FOLDER_OPEN);
+	return folder->open_state == FOLDER_OPEN;
 } 
 
 
@@ -787,22 +608,13 @@ _is_open (CamelFolder *folder, CamelException *ex)
  * Return value: true if the folder exists, false otherwise
  **/
 gboolean
-camel_folder_is_open (CamelFolder *folder, CamelException *ex)
+camel_folder_is_open (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	return (CF_CLASS(folder)->is_open (folder, ex));
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->is_open (folder);
 } 
 
 
-
-
-
 static CamelFolder *
 _get_subfolder (CamelFolder *folder, 
 		const gchar *folder_name, 
@@ -813,27 +625,7 @@ _get_subfolder (CamelFolder *folder,
 	const gchar *current_folder_full_name;
 	gchar separator;
 	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	
-	if (!folder_name) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_INVALID_PARAM,
-				     "folder_name parameter is NULL");
-		return NULL;
-	}	
-	
-	if (!folder->parent_store) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "folder has no parent store");
-		return NULL;
-	}
+	g_assert (folder->parent_store != NULL);
 	
 	current_folder_full_name = camel_folder_get_full_name (folder, ex);
 	if (camel_exception_get_id (ex)) return NULL;
@@ -863,23 +655,11 @@ _get_subfolder (CamelFolder *folder,
 CamelFolder *
 camel_folder_get_subfolder (CamelFolder *folder, gchar *folder_name, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-	
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_subfolder is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (folder_name != NULL);
+	g_assert (camel_folder_is_open (folder));
 
-	return (CF_CLASS(folder)->get_subfolder(folder,folder_name, ex));
+	return CF_CLASS (folder)->get_subfolder (folder, folder_name, ex);
 }
 
 
@@ -907,35 +687,12 @@ _create (CamelFolder *folder, CamelException *ex)
 	CamelFolder *parent;
 	gchar sep;
 	
-	g_assert (folder);
-	g_assert (folder->parent_store);
-	g_assert (folder->name);
+	g_assert (folder->parent_store != NULL);
+	g_assert (folder->name != NULL);
 	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	
-	if (!folder->name) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "folder has no name");
-		return FALSE;
-	}	
-	
-	if (!folder->parent_store) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "folder has no parent store");
-		return FALSE;
-	}
-
 	/* if the folder already exists on the 
 	   store, do nothing and return true */
-	if (CF_CLASS(folder)->exists (folder, ex))
+	if (CF_CLASS (folder)->exists (folder, ex))
 		return TRUE;
 	
 	
@@ -982,23 +739,10 @@ _create (CamelFolder *folder, CamelException *ex)
 gboolean
 camel_folder_create (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	/* check if the folder is closed */
-	if (camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return FALSE;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::create is valid only on close folders");
-		return FALSE;		
-	}
+	g_assert (folder != NULL);
+	g_assert (!camel_folder_is_open (folder));
 
-	return (CF_CLASS(folder)->create(folder, ex));
+	return CF_CLASS (folder)->create (folder, ex);
 }
 
 
@@ -1035,20 +779,11 @@ _delete (CamelFolder *folder, gboolean recurse, CamelException *ex)
 	GList *sf;
 	gboolean ok;
 	
-	g_assert(folder);
-	
-	/* method valid only on closed folders */
-	if (folder->open_state != FOLDER_CLOSE) {
-		camel_exception_set (ex, CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "Delete operation invalid on opened folders");
-		return FALSE;
-	}
-	
 	/* delete all messages in the folder */
-	CF_CLASS(folder)->delete_messages(folder, ex);
+	CF_CLASS (folder)->delete_messages (folder, ex);
 	if (camel_exception_get_id (ex)) return FALSE;
 
-	subfolders = CF_CLASS(folder)->list_subfolders(folder, ex); 
+	subfolders = CF_CLASS (folder)->list_subfolders (folder, ex); 
 	if (camel_exception_get_id (ex)) {
 		if (subfolders) g_list_free (subfolders);
 		return FALSE;
@@ -1059,7 +794,7 @@ _delete (CamelFolder *folder, gboolean recurse, CamelException *ex)
 		if (subfolders) {
 			sf = subfolders;
 			do {
-				CF_CLASS(sf->data)->delete(CAMEL_FOLDER(sf->data), TRUE, ex);
+				CF_CLASS (sf->data)->delete (CAMEL_FOLDER (sf->data), TRUE, ex);
 				if (camel_exception_get_id (ex)) ok = FALSE;
 			} while (ok && (sf = sf->next));
 		}
@@ -1093,23 +828,10 @@ _delete (CamelFolder *folder, gboolean recurse, CamelException *ex)
 gboolean 
 camel_folder_delete (CamelFolder *folder, gboolean recurse, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	/* check if the folder is closed */
-	if (camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return FALSE;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::delete is valid only on closed folders");
-		return FALSE;		
-	}
+	g_assert (folder != NULL);
+	g_assert (!camel_folder_is_open (folder));
 
-	return CF_CLASS(folder)->delete(folder, recurse, ex);
+	return CF_CLASS (folder)->delete (folder, recurse, ex);
 }
 
 
@@ -1127,13 +849,6 @@ camel_folder_delete (CamelFolder *folder, gboolean recurse, CamelException *ex)
 static gboolean 
 _delete_messages (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
 	CAMEL_LOG_WARNING ("Calling CamelFolder::delete_messages directly. "
 			   "Should be overloaded\n");
 	return FALSE;
@@ -1151,23 +866,10 @@ _delete_messages (CamelFolder *folder, CamelException *ex)
 gboolean
 camel_folder_delete_messages (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	/* check if the folder is closed */
-	if (camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return FALSE;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::delete_messages is valid only on closed folders");
-		return FALSE;		
-	}
+	g_assert (folder != NULL);
+	g_assert (!camel_folder_is_open (folder));
 
-	return CF_CLASS(folder)->delete_messages(folder, ex);
+	return CF_CLASS (folder)->delete_messages (folder, ex);
 }
 
 
@@ -1186,13 +888,6 @@ camel_folder_delete_messages (CamelFolder *folder, CamelException *ex)
 static CamelFolder *
 _get_parent_folder (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	return folder->parent_folder;
 }
 
@@ -1208,14 +903,8 @@ _get_parent_folder (CamelFolder *folder, CamelException *ex)
 CamelFolder *
 camel_folder_get_parent_folder (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	return CF_CLASS(folder)->get_parent_folder(folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->get_parent_folder (folder, ex);
 }
 
 
@@ -1230,13 +919,6 @@ camel_folder_get_parent_folder (CamelFolder *folder, CamelException *ex)
 static CamelStore *
 _get_parent_store (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	return folder->parent_store;
 }
 
@@ -1252,14 +934,8 @@ _get_parent_store (CamelFolder *folder, CamelException *ex)
 CamelStore *
 camel_folder_get_parent_store (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	return CF_CLASS(folder)->get_parent_store(folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->get_parent_store (folder, ex);
 }
 
 
@@ -1268,13 +944,6 @@ camel_folder_get_parent_store (CamelFolder *folder, CamelException *ex)
 static CamelFolderOpenMode
 _get_mode (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FOLDER_OPEN_UNKNOWN;
-	}
-
 	return folder->open_mode;
 }
 
@@ -1290,14 +959,8 @@ _get_mode (CamelFolder *folder, CamelException *ex)
 CamelFolderOpenMode
 camel_folder_get_mode (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FOLDER_OPEN_UNKNOWN;
-	}
-
-	return CF_CLASS(folder)->get_mode(folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->get_mode (folder, ex);
 }
 
 
@@ -1306,13 +969,6 @@ camel_folder_get_mode (CamelFolder *folder, CamelException *ex)
 static GList *
 _list_subfolders (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	CAMEL_LOG_WARNING ("Calling CamelFolder::list_subfolders directly. "
 			   "Should be overloaded\n");
 	return NULL;
@@ -1330,23 +986,10 @@ _list_subfolders (CamelFolder *folder, CamelException *ex)
 GList *
 camel_folder_list_subfolders (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-	
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::list_subfolder is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
-	return CF_CLASS(folder)->list_subfolders(folder, ex);
+	return CF_CLASS (folder)->list_subfolders (folder, ex);
 }
 
 
@@ -1355,13 +998,6 @@ camel_folder_list_subfolders (CamelFolder *folder, CamelException *ex)
 static GList *
 _expunge (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	CAMEL_LOG_WARNING ("Calling CamelFolder::expunge directly. "
 			   "Should be overloaded\n");
 	return NULL;
@@ -1377,39 +1013,19 @@ _expunge (CamelFolder *folder, CamelException *ex)
  * Return value: list of expunged messages 
  **/
 GList *
-camel_folder_expunge (CamelFolder *folder,  CamelException *ex)
+camel_folder_expunge (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-	
-	/* check if the folder is closed */
-	if (camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::expunge is valid only on closed folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (!camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->expunge (folder, ex);
 }
 
 
 static gboolean 
-_has_message_number_capability (CamelFolder *folder, CamelException *ex)
+_has_message_number_capability (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	CAMEL_LOG_WARNING ("Calling CamelFolder::has_message_number_capability directly. "
+	CAMEL_LOG_WARNING ("Calling CamelFolder::has_message_number_capability  directly. "
 			   "Should be overloaded\n");
 	return FALSE;
 
@@ -1430,16 +1046,10 @@ _has_message_number_capability (CamelFolder *folder, CamelException *ex)
  * Return value: TRUE if the folder supports message numbering, FALSE otherwise.
  **/
 gboolean 
-camel_folder_has_message_number_capability (CamelFolder *folder, CamelException *ex)
+camel_folder_has_message_number_capability (CamelFolder *folder)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
-	return CF_CLASS(folder)->has_message_number_capability (folder, ex);
+	g_assert (folder != NULL);
+	return CF_CLASS (folder)->has_message_number_capability (folder);
 }
 
 
@@ -1448,15 +1058,8 @@ camel_folder_has_message_number_capability (CamelFolder *folder, CamelException
 static CamelMimeMessage *
 _get_message_by_number (CamelFolder *folder, gint number, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	CAMEL_LOG_WARNING ("Calling CamelFolder::get_message_by_number directly. "
-			   "Should be overloaded\n");
+	CAMEL_LOG_WARNING ("Calling CamelFolder::get_message_by_number "
+			   "directly. Should be overloaded\n");
 	return NULL;
 }
 
@@ -1475,21 +1078,8 @@ _get_message_by_number (CamelFolder *folder, gint number, CamelException *ex)
 CamelMimeMessage *
 camel_folder_get_message_by_number (CamelFolder *folder, gint number, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_message_by_number is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->get_message_by_number (folder, number, ex);
 }
@@ -1516,36 +1106,17 @@ _get_message_count (CamelFolder *folder, CamelException *ex)
 gint
 camel_folder_get_message_count (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return -1;
-	}
-	
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return -1;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_message_count is valid only on open folders");
-		return -1;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->get_message_count (folder, ex);
 }
 
 
 static void
-_append_message (CamelFolder *folder, CamelMimeMessage *message, CamelException *ex)
+_append_message (CamelFolder *folder, CamelMimeMessage *message,
+		 CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
 	CAMEL_LOG_WARNING ("Calling CamelFolder::append_message directly. "
 			   "Should be overloaded\n");
 	return;
@@ -1567,21 +1138,8 @@ camel_folder_append_message (CamelFolder *folder,
 			     CamelMimeMessage *message, 
 			     CamelException *ex)
 {	
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::append_message is valid only on open folders");
-		return;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
 	CF_CLASS (folder)->append_message (folder, message, ex);
 }
@@ -1590,13 +1148,6 @@ camel_folder_append_message (CamelFolder *folder,
 static const GList *
 _list_permanent_flags (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
 	return folder->permanent_flags;
 }
 
@@ -1604,13 +1155,7 @@ _list_permanent_flags (CamelFolder *folder, CamelException *ex)
 const GList *
 camel_folder_list_permanent_flags (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
+	g_assert (folder != NULL);
 	return CF_CLASS (folder)->list_permanent_flags (folder, ex);
 }
 
@@ -1620,13 +1165,6 @@ camel_folder_list_permanent_flags (CamelFolder *folder, CamelException *ex)
 static void
 _copy_message_to (CamelFolder *folder, CamelMimeMessage *message, CamelFolder *dest_folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
 	camel_folder_append_message (dest_folder, message, ex);
 }
 
@@ -1637,21 +1175,8 @@ camel_folder_copy_message_to (CamelFolder *folder,
 			      CamelFolder *dest_folder, 
 			      CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::copy_message_to is valid only on open folders");
-		return;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
 	CF_CLASS (folder)->copy_message_to (folder, message, dest_folder, ex);;
 }
@@ -1663,16 +1188,9 @@ camel_folder_copy_message_to (CamelFolder *folder,
 /* summary stuff */
 
 gboolean
-camel_folder_has_summary_capability (CamelFolder *folder, 
-				     CamelException *ex)
+camel_folder_has_summary_capability (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
+	g_assert (folder != NULL);
 	return folder->has_summary_capability;
 }
 
@@ -1692,21 +1210,8 @@ CamelFolderSummary *
 camel_folder_get_summary (CamelFolder *folder, 
 			  CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_summary is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (camel_folder_is_open (folder));
 
 	return folder->summary;
 }
@@ -1727,15 +1232,9 @@ camel_folder_get_summary (CamelFolder *folder,
  * Return value: TRUE if the folder supports UIDs 
  **/
 gboolean
-camel_folder_has_uid_capability (CamelFolder *folder, CamelException *ex)
+camel_folder_has_uid_capability (CamelFolder *folder)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return FALSE;
-	}
-
+	g_assert (folder != NULL);
 	return folder->has_uid_capability;
 }
 
@@ -1764,28 +1263,9 @@ _get_message_uid (CamelFolder *folder, CamelMimeMessage *message, CamelException
 const gchar * 
 camel_folder_get_message_uid (CamelFolder *folder, CamelMimeMessage *message, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	if (!folder->has_uid_capability) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NON_UID,
-				     "folder is not UID capable");
-		return NULL;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_message_uid is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (folder->has_uid_capability);
+	g_assert (camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->get_message_uid (folder, message, ex);
 }
@@ -1793,18 +1273,13 @@ camel_folder_get_message_uid (CamelFolder *folder, CamelMimeMessage *message, Ca
 
 
 /* the next two func are left there temporarily */
+#if 0
+
 static const gchar *
 _get_message_uid_by_number (CamelFolder *folder, gint message_number, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	CAMEL_LOG_WARNING ("Calling CamelFolder::get_message_uid_by_number directly. "
-			   "Should be overloaded\n");
+	CAMEL_LOG_WARNING ("Calling CamelFolder::get_message_uid_by_number "
+			   "directly. Should be overloaded\n");
 	return NULL;
 }
 
@@ -1827,19 +1302,14 @@ camel_folder_get_message_uid_by_number (CamelFolder *folder, gint message_number
 const gchar * 
 camel_folder_get_message_uid_by_number (CamelFolder *folder, gint message_number, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
+	g_assert (folder != NULL);
 
 	/*  if (!folder->has_uid_capability) return NULL; */
 	/*  return CF_CLASS (folder)->get_message_uid_by_number (folder, message_number, ex); */
 	
 	return NULL;
 }
-
+#endif /* 0 */
 
 static CamelMimeMessage *
 _get_message_by_uid (CamelFolder *folder, const gchar *uid, CamelException *ex)
@@ -1864,29 +1334,9 @@ _get_message_by_uid (CamelFolder *folder, const gchar *uid, CamelException *ex)
 CamelMimeMessage *
 camel_folder_get_message_by_uid  (CamelFolder *folder, const gchar *uid, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	if (!folder->has_uid_capability) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NON_UID,
-				     "folder is not UID capable");
-		return NULL;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_message_by_uid is valid only on open folders");
-		return NULL;		
-	}
-
+	g_assert (folder != NULL);
+	g_assert (folder->has_uid_capability);
+	g_assert (camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->get_message_by_uid (folder, uid, ex);
 }
@@ -1894,20 +1344,6 @@ camel_folder_get_message_by_uid  (CamelFolder *folder, const gchar *uid, CamelEx
 static GList *
 _get_uid_list  (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	if (!folder->has_uid_capability) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NON_UID,
-				     "folder is not UID capable");
-		return NULL;
-	}
-
 	CAMEL_LOG_WARNING ("Calling CamelFolder::get_uid_list directly. "
 			   "Should be overloaded\n");
 	return NULL;
@@ -1928,28 +1364,9 @@ _get_uid_list  (CamelFolder *folder, CamelException *ex)
 GList *
 camel_folder_get_uid_list  (CamelFolder *folder, CamelException *ex)
 {
-	if (!folder) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NULL,
-				     "folder object is NULL");
-		return NULL;
-	}
-
-	if (!folder->has_uid_capability) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_NON_UID,
-				     "folder is not UID capable");
-		return NULL;
-	}
-
-	/* check if the folder is open */
-	if (!camel_folder_is_open (folder, ex)) {
-		if (camel_exception_get_id (ex)) return NULL;
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID_STATE,
-				     "CamelFolder::get_uid_list is valid only on open folders");
-		return NULL;		
-	}
+	g_assert (folder != NULL);
+	g_assert (folder->has_uid_capability);
+	g_assert (camel_folder_is_open (folder));
 
 	return CF_CLASS (folder)->get_uid_list (folder, ex);
 }
@@ -1963,15 +1380,9 @@ camel_folder_get_uid_list  (CamelFolder *folder, CamelException *ex)
  * Return value: TRUE if the folder supports UIDs 
  **/
 gboolean
-camel_folder_has_search_capability (CamelFolder *folder, CamelException *ex)
+camel_folder_has_search_capability (CamelFolder *folder)
 {
-	if (!CAMEL_IS_FOLDER(folder)) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "Invalid folder");
-		return FALSE;
-	}
-
+	g_assert (folder != NULL);
 	return folder->has_search_capability;
 }
 
@@ -1979,12 +1390,8 @@ GList *camel_folder_search_by_expression  (CamelFolder *folder,
 					   const char *expression,
 					   CamelException *ex)
 {
-	if (!CAMEL_IS_FOLDER(folder)) {
-		camel_exception_set (ex, 
-				     CAMEL_EXCEPTION_FOLDER_INVALID,
-				     "Invalid folder");
-		return NULL;
-	}
+	g_assert (folder != NULL);
+	g_assert (folder->has_search_capability);
 
 	return CF_CLASS (folder)->search_by_expression (folder, expression, ex);
 }