Chris Muller uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-cmm.918.mcz

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

Name: System-cmm.918
Author: cmm
Time: 22 November 2016, 5:17:50.933976 pm
UUID: 508aa5e7-48e0-4137-bb2d-7bbb96a1a722
Ancestors: System-tfel.917

Guard against patching a newer system with an older patch file.

=============== Diff against System-tfel.917 ===============

Item was changed:
  ----- Method: SmalltalkImage>>patchSystem (in category 'command line') -----
  patchSystem
+ 	'patch.st' asDirectoryEntry ifNotNil:
+ 		[ : patchEntry | patchEntry modificationTime > Smalltalk imageName asDirectoryEntry modificationTime
+ 			ifTrue:
+ 				[ Notification signal: 'Patching system...'.
+ 				FileStream
+ 					fileNamed: 'patch.st'
+ 					do:
+ 						[ : stream | stream fileIn ] ]
+ 			ifFalse: [ self error: 'patch.st file is older than the image file.  Aborting.' ] ]!
- 	(FileDirectory default fileExists: 'patch.st') ifTrue:
- 		[Notification signal: 'Patching system...'.
- 		FileStream
- 			fileNamed: 'patch.st'
- 			do: [ : stream | stream fileIn ] ]!