diff --git a/api/moo.xml b/api/moo.xml
index af0f3e48..47e02938 100644
--- a/api/moo.xml
+++ b/api/moo.xml
@@ -168,7 +168,7 @@
   <class gtype_id="MOO_TYPE_EDIT_OPEN_INFO" name="MooEditOpenInfo" parent="GObject" short_name="EditOpenInfo">
     <constructor c_name="moo_edit_open_info_new" name="edit_open_info_new">
       <param name="file" type="GFile*" />
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
       <retval type="MooEditOpenInfo*" />
     </constructor>
     <method c_name="moo_edit_open_info_dup" name="dup">
@@ -177,7 +177,7 @@
   </class>
   <class gtype_id="MOO_TYPE_EDIT_RELOAD_INFO" name="MooEditReloadInfo" parent="GObject" short_name="EditReloadInfo">
     <constructor c_name="moo_edit_reload_info_new" name="edit_reload_info_new">
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
       <retval type="MooEditReloadInfo*" />
     </constructor>
     <method c_name="moo_edit_reload_info_dup" name="dup">
@@ -187,7 +187,7 @@
   <class gtype_id="MOO_TYPE_EDIT_SAVE_INFO" name="MooEditSaveInfo" parent="GObject" short_name="EditSaveInfo">
     <constructor c_name="moo_edit_save_info_new" name="edit_save_info_new">
       <param name="file" type="GFile*" />
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
       <retval type="MooEditSaveInfo*" />
     </constructor>
     <method c_name="moo_edit_save_info_dup" name="dup">
@@ -501,7 +501,7 @@
     </method>
     <method c_name="moo_ui_xml_add_ui_from_string" name="add_ui_from_string">
       <param name="buffer" type="const-char*" />
-      <param name="length" type="gssize" />
+      <param default_value="-1" name="length" type="int" />
     </method>
     <method c_name="moo_ui_xml_create_widget" name="create_widget">
       <param name="type" type="MooUiWidgetType" />
@@ -604,9 +604,9 @@
   <boxed gtype_id="MOO_TYPE_PLUGIN_INFO" name="MooPluginInfo" short_name="PluginInfo">
     <constructor c_name="moo_plugin_info_new" name="plugin_info_new">
       <param name="name" type="const-char*" />
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="description" type="const-char*" />
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="author" type="const-char*" />
-      <param allow_none="1" default_value="&quot;NULL&quot;" name="version" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="description" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="author" type="const-char*" />
+      <param allow_none="1" default_value="NULL" name="version" type="const-char*" />
       <retval type="MooPluginInfo*" />
     </constructor>
   </boxed>
@@ -637,8 +637,8 @@
     <param name="name" type="const-char*" />
     <param name="display_name" type="const-char*" />
     <param name="factory" type="MooCommandFactory*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="keys" type="strv" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="extension" type="const-char*" />
+    <param allow_none="1" default_value="NULL" name="keys" type="strv" />
+    <param allow_none="1" default_value="NULL" name="extension" type="const-char*" />
   </function>
   <function c_name="moo_dgettext" name="dgettext">
     <param name="domain" type="const-char*" />
@@ -647,22 +647,22 @@
   </function>
   <function c_name="moo_edit_open_info_new_path" name="edit_open_info_new_path">
     <param name="path" type="const-char*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+    <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
     <retval transfer_mode="full" type="MooEditOpenInfo*" />
   </function>
   <function c_name="moo_edit_open_info_new_uri" name="edit_open_info_new_uri">
     <param name="uri" type="const-char*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+    <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
     <retval transfer_mode="full" type="MooEditOpenInfo*" />
   </function>
   <function c_name="moo_edit_save_info_new_path" name="edit_save_info_new_path">
     <param name="path" type="const-char*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+    <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
     <retval transfer_mode="full" type="MooEditSaveInfo*" />
   </function>
   <function c_name="moo_edit_save_info_new_uri" name="edit_save_info_new_uri">
     <param name="uri" type="const-char*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="encoding" type="const-char*" />
+    <param allow_none="1" default_value="NULL" name="encoding" type="const-char*" />
     <retval transfer_mode="full" type="MooEditSaveInfo*" />
   </function>
   <function c_name="moo_edit_window_set_action_filter" name="edit_window_set_action_filter">
@@ -685,7 +685,7 @@
     <param name="id" type="const-char*" />
     <param name="type" type="GType" />
     <param name="info" type="const-MooPluginInfo*" />
-    <param allow_none="1" default_value="&quot;NULL&quot;" name="params" type="const-MooPluginParams*" />
+    <param allow_none="1" default_value="NULL" name="params" type="const-MooPluginParams*" />
     <retval type="gboolean" />
   </function>
   <function c_name="moo_prefs_get_bool" name="prefs_get_bool">
diff --git a/moo/mooedit/mooeditfileinfo.c b/moo/mooedit/mooeditfileinfo.c
index b1d17635..0ff1da67 100644
--- a/moo/mooedit/mooeditfileinfo.c
+++ b/moo/mooedit/mooeditfileinfo.c
@@ -26,7 +26,7 @@ G_DEFINE_TYPE (MooEditReloadInfo, moo_edit_reload_info, G_TYPE_OBJECT)
  * moo_edit_open_info_new: (constructor-of MooEditOpenInfo)
  *
  * @file:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  **/
 MooEditOpenInfo *
 moo_edit_open_info_new (GFile      *file,
@@ -49,7 +49,7 @@ moo_edit_open_info_new (GFile      *file,
  * moo_edit_open_info_new_path:
  *
  * @path:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  *
  * Returns: (transfer full)
  **/
@@ -67,7 +67,7 @@ moo_edit_open_info_new_path (const char *path,
  * moo_edit_open_info_new_uri:
  *
  * @uri:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  *
  * Returns: (transfer full)
  **/
@@ -130,7 +130,7 @@ moo_edit_open_info_init (MooEditOpenInfo *info)
  * moo_edit_save_info_new: (constructor-of MooEditSaveInfo)
  *
  * @file:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  **/
 MooEditSaveInfo *
 moo_edit_save_info_new (GFile      *file,
@@ -152,7 +152,7 @@ moo_edit_save_info_new (GFile      *file,
  * moo_edit_save_info_new_path:
  *
  * @path:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  *
  * Returns: (transfer full)
  **/
@@ -170,7 +170,7 @@ moo_edit_save_info_new_path (const char *path,
  * moo_edit_save_info_new_uri:
  *
  * @uri:
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  *
  * Returns: (transfer full)
  **/
@@ -228,7 +228,7 @@ moo_edit_save_info_init (G_GNUC_UNUSED MooEditSaveInfo *info)
 /**
  * moo_edit_reload_info_new: (constructor-of MooEditReloadInfo)
  *
- * @encoding: (allow-none) (default "NULL")
+ * @encoding: (allow-none) (default NULL)
  **/
 MooEditReloadInfo *
 moo_edit_reload_info_new (const char *encoding)
diff --git a/moo/mooedit/mooplugin.c b/moo/mooedit/mooplugin.c
index cc5bf4e8..9e021c61 100644
--- a/moo/mooedit/mooplugin.c
+++ b/moo/mooedit/mooplugin.c
@@ -233,7 +233,7 @@ moo_plugin_class_init (MooPluginClass *klass)
  * @id:
  * @type:
  * @info:
- * @params: (allow-none) (default "NULL")
+ * @params: (allow-none) (default NULL)
  **/
 gboolean
 moo_plugin_register (const char            *id,
@@ -1116,9 +1116,9 @@ moo_plugin_set_win_plugin_type (MooPlugin *plugin,
  * moo_plugin_info_new: (constructor-of MooPluginInfo)
  *
  * @name:
- * @description: (allow-none) (default "NULL")
- * @author: (allow-none) (default "NULL")
- * @version: (allow-none) (default "NULL")
+ * @description: (allow-none) (default NULL)
+ * @author: (allow-none) (default NULL)
+ * @version: (allow-none) (default NULL)
  */
 MooPluginInfo *
 moo_plugin_info_new (const char     *name,
diff --git a/moo/moolua/moo-lua-api.cpp b/moo/moolua/moo-lua-api.cpp
index 0e2b8f8f..54c9d2f9 100644
--- a/moo/moolua/moo-lua-api.cpp
+++ b/moo/moolua/moo-lua-api.cpp
@@ -806,6 +806,16 @@ cfunc_MooUiXml_add_item (gpointer pself, G_GNUC_UNUSED lua_State *L, G_GNUC_UNUS
     return moo_lua_push_instance (L, ret, MOO_TYPE_UI_NODE, TRUE);
 }
 
+static int
+cfunc_MooUiXml_add_ui_from_string (gpointer pself, G_GNUC_UNUSED lua_State *L, G_GNUC_UNUSED int first_arg)
+{
+    MooUiXml *self = (MooUiXml*) pself;
+    const char* arg0 = moo_lua_get_arg_string (L, first_arg + 0, "buffer");
+    int arg1 = moo_lua_get_arg_int_opt (L, first_arg + 1, "length", -1);
+    moo_ui_xml_add_ui_from_string (self, arg0, arg1);
+    return 0;
+}
+
 static int
 cfunc_MooUiXml_create_widget (gpointer pself, G_GNUC_UNUSED lua_State *L, G_GNUC_UNUSED int first_arg)
 {
@@ -1114,6 +1124,7 @@ moo_lua_api_register (void)
 
     MooLuaMethodEntry methods_MooUiXml[] = {
         { "add_item", cfunc_MooUiXml_add_item },
+        { "add_ui_from_string", cfunc_MooUiXml_add_ui_from_string },
         { "create_widget", cfunc_MooUiXml_create_widget },
         { "find_placeholder", cfunc_MooUiXml_find_placeholder },
         { "get_node", cfunc_MooUiXml_get_node },
diff --git a/moo/moopython/pygtk/moo-generated.defs b/moo/moopython/pygtk/moo-generated.defs
index 4d054e80..d1a31e4c 100644
--- a/moo/moopython/pygtk/moo-generated.defs
+++ b/moo/moopython/pygtk/moo-generated.defs
@@ -713,7 +713,7 @@
   (is-constructor-of MooEditOpenInfo)
   (parameters
     '("GFile*" "file")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -731,7 +731,7 @@
   (return-type "MooEditReloadInfo*")
   (is-constructor-of MooEditReloadInfo)
   (parameters
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -750,7 +750,7 @@
   (is-constructor-of MooEditSaveInfo)
   (parameters
     '("GFile*" "file")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -1546,7 +1546,7 @@
   (return-type "none")
   (parameters
     '("const-char*" "buffer")
-    '("gssize" "length")
+    '("int" "length" (default "-1"))
   )
 )
 
@@ -1750,9 +1750,9 @@
   (is-constructor-of MooPluginInfo)
   (parameters
     '("const-char*" "name")
-    '("const-char*" "description" (null-ok) (default ""NULL""))
-    '("const-char*" "author" (null-ok) (default ""NULL""))
-    '("const-char*" "version" (null-ok) (default ""NULL""))
+    '("const-char*" "description" (null-ok) (default "NULL"))
+    '("const-char*" "author" (null-ok) (default "NULL"))
+    '("const-char*" "version" (null-ok) (default "NULL"))
   )
 )
 
@@ -1795,8 +1795,8 @@
     '("const-char*" "name")
     '("const-char*" "display_name")
     '("MooCommandFactory*" "factory")
-    '("strv" "keys" (null-ok) (default ""NULL""))
-    '("const-char*" "extension" (null-ok) (default ""NULL""))
+    '("strv" "keys" (null-ok) (default "NULL"))
+    '("const-char*" "extension" (null-ok) (default "NULL"))
   )
 )
 
@@ -1815,7 +1815,7 @@
   (caller-owns-return #t)
   (parameters
     '("const-char*" "path")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -1825,7 +1825,7 @@
   (caller-owns-return #t)
   (parameters
     '("const-char*" "uri")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -1835,7 +1835,7 @@
   (caller-owns-return #t)
   (parameters
     '("const-char*" "path")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -1845,7 +1845,7 @@
   (caller-owns-return #t)
   (parameters
     '("const-char*" "uri")
-    '("const-char*" "encoding" (null-ok) (default ""NULL""))
+    '("const-char*" "encoding" (null-ok) (default "NULL"))
   )
 )
 
@@ -1888,7 +1888,7 @@
     '("const-char*" "id")
     '("GType" "type")
     '("const-MooPluginInfo*" "info")
-    '("const-MooPluginParams*" "params" (null-ok) (default ""NULL""))
+    '("const-MooPluginParams*" "params" (null-ok) (default "NULL"))
   )
 )
 
diff --git a/moo/plugins/usertools/moocommand.c b/moo/plugins/usertools/moocommand.c
index 0c75dc34..b1f2d7cf 100644
--- a/moo/plugins/usertools/moocommand.c
+++ b/moo/plugins/usertools/moocommand.c
@@ -130,8 +130,8 @@ moo_command_create (const char     *name,
  * @name:
  * @display_name:
  * @factory:
- * @keys: (type strv) (allow-none) (default "NULL")
- * @extension: (allow-none) (default "NULL")
+ * @keys: (type strv) (allow-none) (default NULL)
+ * @extension: (allow-none) (default NULL)
  **/
 void
 moo_command_factory_register (const char        *name,