Nicolas Cellier uploaded a new version of MorphicExtras to project The Trunk:
http://source.squeak.org/trunk/MorphicExtras-nice.48.mcz

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

Name: MorphicExtras-nice.48
Author: nice
Time: 4 October 2009, 8:33:03 am
UUID: 2321e50d-1bba-458c-a955-04ce93e2c54e
Ancestors: MorphicExtras-ar.47

Fix bug http://bugs.squeak.org/view.php?id=6732
In SketchEditorMorph, using undo on a polygon put it in a non-functioning state.

=============== Diff against MorphicExtras-ar.47 ===============

Item was changed:
  ----- Method: SketchEditorMorph>>polyFreeze (in category 'actions & preps') -----
  polyFreeze
  	"A live polygon is on the painting.  Draw it into the painting and
  delete it."
  
  	| poly |
  	self polyEditing ifFalse:[^self].
+ 	(poly := self valueOfProperty: #polygon)
+ 		ifNil:
+ 			[self polyEditing: false.
+ 			^ self].
- 	(poly := self valueOfProperty: #polygon) ifNil: [^ self].
  	poly drawOn: formCanvas.
  	poly delete.
  	self setProperty: #polygon toValue: nil.
  	self polyEditing: false.!

Item was changed:
  ----- Method: SketchEditorMorph>>undo: (in category 'start & finish') -----
  undo: evt 
  	"revert to a previous state.  "
  
  	| temp poly pen |
  	self flag: #bob.	"what is undo in multihand environment?"
  	undoBuffer ifNil: [^Beeper beep].	"nothing to go back to"
  	(poly := self valueOfProperty: #polygon) ifNotNil: 
  			[poly delete.
  			self setProperty: #polygon toValue: nil.
+ 			self polyEditing: false.
  			^self].
  	temp := paintingForm.
  	paintingForm := undoBuffer.
  	undoBuffer := temp.	"can get back to what you had by undoing again"
  	pen := self get: #paintingFormPen for: evt.
  	pen ifNil: [^Beeper  beep].
  	pen setDestForm: paintingForm.
  	formCanvas := paintingForm getCanvas.	"used for lines, ovals, etc."
  	formCanvas := formCanvas copyOrigin: self topLeft negated
  				clipRect: (0 @ 0 extent: bounds extent).
  	self render: bounds!