window: clear lvobj before deleting it

radio/src/thirdparty/libopenui/src/keyboard_base.cpp

@@ -104,13 +104,19 @@ void Keyboard::clearField()
   if (field) {
     // restore field's group
     auto obj = field->getLvObj();
-    lv_obj_remove_event_cb(obj, field_focus_leave);
-    lv_group_t* g = (lv_group_t*)lv_obj_get_group(obj);
-    if (g) _assign_lv_group(g);
+    if (obj) {
+      lv_obj_remove_event_cb(obj, field_focus_leave);
+    }
     
     field->setEditMode(false);
     field->changeEnd();
     field = nullptr;
+
+    if (fieldGroup) {
+      _assign_lv_group(fieldGroup);
+      lv_group_set_editing(fieldGroup, false);
+      fieldGroup = nullptr;
+    }
   }
 }
 
@@ -165,6 +171,7 @@ void Keyboard::setField(FormField* newField)
       _assign_lv_group(group);
       
       field = newField;
+      fieldGroup = (lv_group_t*)lv_obj_get_group(obj);
     }
   }
 }

radio/src/thirdparty/libopenui/src/keyboard_base.h

@@ -40,6 +40,7 @@ class Keyboard : public Window
 
   FormField* field = nullptr;
   Window* fieldContainer = nullptr;
+  lv_group_t* fieldGroup = nullptr;
   lv_coord_t scroll_pos = 0;
 
   void setField(FormField* newField);

radio/src/thirdparty/libopenui/src/window.cpp

@@ -328,8 +328,9 @@ void Window::deleteLater(bool detach, bool trash)
   deleteChildren();
 
   if (lvobj != nullptr) {
-    lv_obj_del(lvobj);
+    auto obj = lvobj;
     lvobj = nullptr;
+    lv_obj_del(obj);
   }
 }