MNU when disabling preference Show world main docking bar

Dear Squeakers,

When I wanted to disable the docking bar I ran into a debugger in an image with latest update #15196. It does not happen in the Squeak5.1-15113.image from the FTP server.

The strange thing is that all the showWorldMainDockingBar(:) methods have not changed for years. So far I did not find the reason for this. Maybe someone of you have a suspicion of what change might have caused that.

Cheers,
Bernhard

I found it. If I revert the change of Preferences class>>#doesNotUnderstand: from 8/27/215 that came with System-topa.764 it works again. I don’t know if this is the right fix as I am sure there was some good reason for the change. Tobias?

Cheers,
Bernhard

P.S.
Here is a strange thing. The mail from [hidden email] look like this:

Tobias Pape uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-topa.764.mcz

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

Name: System-topa.764
Author: topa
Time: 27 August 2015, 11:47:04.664 pm
UUID: c205a736-8aff-48c5-8b3b-24ec808d19fd
Ancestors: System-topa.763

Do not return nil for unknown preferences in dNU magic but rather bail.

=============== Diff against System-topa.763 ===============

Item was changed:
 ----- Method: Preferences class>>doesNotUnderstand: (in category 'get/set') -----
 doesNotUnderstand: aMessage
  "Interpret unary message selectors as preference id."
 
  ^ aMessage arguments size > 0
  ifTrue: [super doesNotUnderstand: aMessage]
+ ifFalse: [
+ self
+ valueOfPreference: aMessage selector
+ ifAbsent: [super doesNotUnderstand: aMessage]]!
- ifFalse: [self valueOfPreference: aMessage selector]!

However, in my trunk image the previous version of the method with the stamp sw 11/11/1998 11:40 looks like this:

doesNotUnderstand: aMessage
        "Look up the message selector as a flag."
        aMessage arguments size > 0
                ifTrue: [^ super doesNotUnderstand: aMessage].
        ^ self valueOfFlag: aMessage selector

Does anyone have an explanation why the intermediate version isn’t in my trunk image?

Fixed: http://forum.world.st/The-Trunk-Morphic-mt-1006-mcz-td4851176.html

Just update. :)

Best,
Marcel

Hi Bernhard,

it's a good thing to have less DNU-magic in the Preferences. There is no default value for all kinds of preferences that could possibly be returned there. It used to be "false" but that makes no sense for, e.g., numeric properties. Returnung "nil" would require more #ifNotNil-checks. Raising an error is fair enough.

Best,
Marcel

Hi Marcel,

I agree. Thanks for the fast fix. This makes reporting bugs more fun. ;-)

Cheers,
Bernhard