I think I know what's causing this bug... somehow the World menu is not accounting for the width of the modified "undo" item, and so it doesn't display the menu to the left of the mouse-click when it should (when it's near the right side of the screen).

You'll notice that if you start up a truly unmodified image in which there's nothing to be undone (so that the menu says "can't undo"), the menu does not have this problem.  But then if you do something like pick up a morph, the menu says something like "undo move SystemWindow" and then the problem happens.

I tracked the problem down to MenuMorph>>positionAt:relativeTo:inWorld: if someone wants to try to fix it.  (See the "If it doesn't fit, show it to the left..." comment)

- Doug Way
  dway at riskmetrics.com


Craig Latta wrote:
> 
> Hi--
> 
>         Apologies if someone has already mentioned this one...
> 
>         Sometimes bringing up a World menu also selects an item from it,
> without allowing a decision as to which item is to be selected. I'm not
> sure of a generic description of this problem, so I'll just describe a
> particular way to invoke it.
> 
>         Start an unmodified, current image. Enable full-screen mode. Collapse
> all windows. Open a workspace, and place it so that its right edge is
> about thirty pixels from the right edge of the screen, at any altitude.
> Now open a World menu by single-clicking on the World (don't hold)
> between the workspace and the right edge of the screen. An item from the
> menu will automatically be selected, which one depends on how close to
> the bottom of the screen you clicked.
> 
>         Very annoying. :)
> 
> -C
> 
> --
> Craig Latta
> composer and computer scientist
> craig.latta at netjam.org
> www.netjam.org
> crl at watson.ibm.com
> Smalltalkers do: [:it | All with: Class, (And love: it)]