Marcel Taeumel uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-mt.828.mcz

==================== Summary ====================

Name: System-mt.828
Author: mt
Time: 9 May 2016, 2:32:42.424999 pm
UUID: 88be4fe7-a85d-da42-aa7b-3df3da6bcb48
Ancestors: System-mt.827

Fixes sub-project lifting, which is an option when deleting projects that have sub-projects.

=============== Diff against System-mt.827 ===============

Item was changed:
  ----- Method: Project>>setParent: (in category 'sub-projects & hierarchy') -----
  setParent: newParent
  
+ 	"Notify the current parent to discard views and other references. Avoids deleting that project later if the former parent is deleted. You can only have one parent anyway.."
+ 	self parent ~= newParent ifTrue: [self parent deletingProject: self].
+ 
  	parentProject := newParent.
  	nextProject := previousProject := nil.!