A new version of Morphic was added to project The Inbox:
http://source.squeak.org/inbox/Morphic-LM.1462.mcz

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

Name: Morphic-LM.1462
Author: LM
Time: 6 September 2018, 12:14:18.079447 pm
UUID: e1c1e0cf-8e19-7e49-99f6-bc98b78ed007
Ancestors: Morphic-cmm.1461

Fixes a NonBooleanReceiver error that appeared when pressing backspace on a read-only text field.

=============== Diff against Morphic-cmm.1461 ===============

Item was changed:
  ----- Method: TextEditor>>backTo: (in category 'typing support') -----
  backTo: startIndex
  	"During typing, backspace to startIndex. If there already is a selection, just delete that selection. Otherwise, check if we did something else than backward-deletion and start a new command if so."
  
+ 	morph readOnly ifTrue: [^ false].
- 	morph readOnly ifTrue: [^ self].
  
  	self hasSelection ifTrue: [
  		"Add checkpoint in undo history."
  		self replaceSelectionWith: self nullText.
  		^ true].
  
  	startIndex > self text size ifTrue: [^ false].
  
  	self selectInvisiblyFrom: startIndex to: self stopIndex-1.
  	
  	self isTypingIn ifTrue: [
  		self history current type = #backward
  			ifFalse: [self closeTypeIn]
  			ifTrue: [
  				"Accumulate all deleted characters in current undo command."
  				self history current contentsBefore replaceFrom: 1 to: 0 with: self selection.
  				self history current intervalBefore in: [:i |
  					self history current intervalBefore: (startIndex to: i last)]]].
  		
  	self openTypeInFor: #backward.
  	self zapSelectionWith: self nullText.
  	
  	^ false!