fix: remove all duplicate children refs when deleting/moving xblocks

Author: djoseph-apphelix

cms/djangoapps/contentstore/xblock_storage_handlers/view_handlers.py

@@ -373,7 +373,7 @@ def _save_xblock(
                 old_parent_location = store.get_parent_location(new_child)
                 if old_parent_location:
                     old_parent = store.get_item(old_parent_location)
-                    old_parent.children.remove(new_child)
+                    old_parent.children = [c for c in old_parent.children if c != new_child]
                     old_parent = save_xblock_with_callback(old_parent, user)
                 else:
                     # the Studio UI currently doesn't present orphaned children, so assume this is an error

xmodule/modulestore/draft_and_published.py

@@ -163,7 +163,7 @@ def update_item_parent(self, item_location, new_parent_location, old_parent_loca
 
         # Remove item from the list of children of old parent.
         if source_item.location in old_parent_item.children:
-            old_parent_item.children.remove(source_item.location)
+            old_parent_item.children = [c for c in old_parent_item.children if c != source_item.location]
             self.update_item(old_parent_item, user_id)  # pylint: disable=no-member
             log.info(
                 '%s removed from %s children',

xmodule/modulestore/split_mongo/split.py

@@ -2540,7 +2540,7 @@ def delete_item(self, usage_locator, user_id, force=False):  # lint-amnesty, pyl
             parent_block_keys = self._get_parents_from_structure(block_key, original_structure)
             for parent_block_key in parent_block_keys:
                 parent_block = new_blocks[parent_block_key]
-                parent_block.fields['children'].remove(block_key)
+                parent_block.fields['children'] = [c for c in parent_block.fields['children'] if c != block_key]
                 parent_block.edit_info.edited_on = datetime.datetime.now(UTC)
                 parent_block.edit_info.edited_by = user_id
                 parent_block.edit_info.previous_version = parent_block.edit_info.update_version