As described in http://developer.apple.com/techpubs/macosx/Essentials/AquaHIGuidelines/AHIGDock/index.html clicking a dock icon should always result in a new window. This is currrently not the case and is IMHO a quite disturbing behaviour.
*** Bug 169511 has been marked as a duplicate of this bug. ***
Invalid. That isn't what the HIGs say at all. To quote from the URL you provided: "Clicking an application icon in the Dock should always result in a window—a document or another appropriate window—becoming active. In a document-based application that is not open when the user clicks the Dock icon, the application should open a new, untitled window." "...When a user clicks an open application's icon in the Dock, the application becomes active and all open unminimized windows are brought to the front; minimized document windows remain in the Dock. If there are no unminimized windows when the user clicks the Dock icon, the last minimized window should be expanded and made active. If no documents are open, the application should open a new window. (If your application is not document based, display the application's main window.)" Now, there are some problems with other aspects of those paragraphs, but clicking the application's dock icon should clearly *not* always result in a new window.
Yes, you are right. My mistake. I didn't mean 'new window' but just 'window'. And if I've looked correclty I would have noticed that such a bug is already filed as #90823 . But apparently I'm too confused, dumb or both to even file this (wrong described) bug just once. Sorry.
*** This bug has been marked as a duplicate of 90823 ***