Merge branch '194-smooth-brush-size-reset' into 'develop'

Resolve "Brush deleted on join"

See merge request slumber/multi-user!124

multi_user/utils.py

@@ -101,11 +101,17 @@ def get_state_str(state):
 
 
 def clean_scene():
-    for type_name in dir(bpy.data):
+    to_delete = [f for f in dir(bpy.data) if f not in ['brushes', 'palettes']]
+    for type_name in to_delete:
         try:
+            sub_collection_to_avoid = [bpy.data.linestyles['LineStyle'], bpy.data.materials['Dots Stroke']]
             type_collection = getattr(bpy.data, type_name)
-            for item in type_collection:
-                type_collection.remove(item)
+            items_to_remove = [i for i in type_collection if i not in sub_collection_to_avoid]
+            for item in items_to_remove:
+                try:
+                    type_collection.remove(item)
+                except:
+                    continue
         except:
             continue