Hi Marcel

With this fix you did here, this test now passes

1. Image Squeak5.3alpha latest update: #19124
2. Put a 'self halt' into the LazyListMorph >> #drawOn: method
3. The lists get red with a yellow X in the System Brower.
4. Ctrl plus stop brings you into an MVC project where you can revert
the 'self halt'
5. Jump back to the original project.

Result: The Morphic project is fixed after an error which caused the
GUI to stop.

Regards
Hannes

On Tue, 15 Oct 2019 11:30:30 0000, commits at source.squeak.org
<commits at source.squeak.org> wrote:
> Marcel Taeumel uploaded a new version of Morphic to project The Trunk:
> http://source.squeak.org/trunk/Morphic-mt.1575.mcz
>
> ==================== Summary ====================
>
> Name: Morphic-mt.1575
> Author: mt
> Time: 15 October 2019, 1:30:24.148785 pm
> UUID: c7bde074-ddad-864a-a5b3-8b078736fe2f
> Ancestors: Morphic-mt.1574
>
> More robustness: (1) Catch both Error and Halt in Morphic drawing and (2)
> Reset drawing errors in morphs when restoring the Display.
>
> =============== Diff against Morphic-mt.1574 ===============
>
> Item was added:
> + ----- Method: MorphicProject>>restoreDisplay (in category 'scheduling &
> debugging') -----
> + restoreDisplay
> + 	"Give all morphs a chance to draw again."
> + 	self world ifNotNil: [:w | w allMorphsDo: [:ea | ea removeProperty:
> #errorOnDraw ]].
> +
> + 	super restoreDisplay.!
>
> Item was changed:
>   ----- Method: WorldState>>displayWorldSafely: (in category 'update cycle')
> -----
>   displayWorldSafely: aWorld
>   	"Update this world's display and keep track of errors during draw
> methods."
>
>   	| finished classesWithErrors |
>   	finished := false.
>   	
>   	[finished] whileFalse: [
> + 		[aWorld displayWorld. finished := true] on: Error, Halt do: [:ex |
> - 		[aWorld displayWorld. finished := true] on: Error do: [:ex |
>   			"Handle a drawing error"
>   			| err rcvr errCtx errMorph |
>   			err := ex description.
>   			rcvr := ex receiver.
>
>   			errCtx := thisContext.
>   			[
>   				errCtx := errCtx sender.
>   				"Search the sender chain to find the morph causing the problem"
>   				[errCtx notNil and:[(errCtx receiver isMorph) not]]
>   					whileTrue:[errCtx := errCtx sender].
>   				"If we're at the root of the context chain then we have a fatal
> drawing problem"
>   				errCtx ifNil:[^Project current fatalDrawingError: err].
>   				errMorph := errCtx receiver.
>   				"If the morph causing the problem has already the #drawError flag set,
>   				then search for the next morph above in the caller chain."
>   				errMorph hasProperty: #errorOnDraw
>   			] whileTrue.
>   			errMorph setProperty: #errorOnDraw toValue: true.
>
>   			"Catch all errors, one for each receiver class."
>   			classesWithErrors ifNil: [classesWithErrors := IdentitySet new].
>   			(classesWithErrors includes: rcvr class) ifFalse: [
>   				classesWithErrors add: rcvr class.
>   				ToolSet debugException: ex].
>
>   			"Repaint all to catch all errors now and not if the debugger will
> appear."
>   			aWorld fullRepaintNeeded.
>   		]].!
>
>
>