Double-click a window's title bar to zoom/minimize bug on OS 10.11

I am having a problem on OS X 10.11 with the System Preference setting for "Double-click a window's title bar to zoom/minimize". The setting is found on the Dock preference panel and it seems to automatically revert or is not being saved properly to NSUserDefaults.


Due to the Dock settings being improperly saved to NSUserDefaults, the OS incorrectly minimizes or zooms windows in a manner that is inconsistent with the Dock Preference settings.


Could someone please confirm or refute my findings so I can determin if this is a bug?


It appears that the NSUserDefaults values for both of the following Dock settings do not match the visual state of the Dock preference panel.

  • AppleMiniaturizeOnDoubleClick
    This is the NSUserDefaults key for the state of the checkbox "Double-click a window's title bar to zoom/minimize". This key may not be pertinent on OS 10.11.
  • AppleActionOnDoubleClick
    This is a newer NSUserDefaults key for the value of the popup menu which contains choices of "zoom" and "minimize". The possible values for this key are "Maximize", "Minimize" or "None" (when the checkbox for "Double-click titlebar..." is unchecked).


STEPS TO REPRODUCE

1. In System Preferences > Dock, uncheck the box for "Double-click a window's title bar to zoom/minimize".


2. Quit or close System Preferences.


3. In Terminal.app read the NSUserDefaults values using:

defaults read NSGlobalDomain


4. Note the values of the 2 keys above:

- AppleMiniaturizeOnDoubleClick should have a value of 0 (false)*

- AppleActionOnDoubleClick should have a value of `None` because the checkbox is unchecked.


5. Open System Preferences and go to Dock panel again. Do not change any settings.


6. In Terminal.app read the NSUserDefaults values (again) using:

defaults read NSGlobalDomain


Note that the value for `AppleActionOnDoubleClick` has changed from 'None' (disabled) to 'Maximize', however the setting has NOT been changed and the checkbox is still *not* enabled.


The OS behavior will now incorrectly minimize or zoom windows even though the checkbox is not checked. The value of the NSUserDefaults settings and the actual window behavior do not match. Simply visiting the Dock panel after Quitting System > preferences cause the values *and* window behavior to incorrectly change.


* In my tests, the value of `AppleMiniaturizeOnDoubleClick` is always 0, regardless of the actual setting in the Dock Preference panel. I believe this key is now used exclusively for OS 10.10 and lower.


Thank you for any assistance in confirming these findings.

I can reproduce the problem. It definitely looks like a bug in the Dock preference pane. Please file a Radar and post the number here, thanks!

Correction


In my initial post I incorrectly state:

> The value of the NSUserDefaults settings and the actual window behavior do not match.


In fact the NSUserDefaults value for `AppleActionOnDoubleClick` and the window behavior do match.


The issues are that:

1. The NSUserDefault value for `AppleActionOnDoubleClick` changes simply by opening the Dock preference panel.

2. The Dock preference panel does not update to reflect the change that was not initiated by the user.


So visually, the checkbox for "Double-click a window's title bar to zoom/minimize" is unchecked, but the saved value of `AppleActionOnDoubleClick` has mysteriously changed to 'Maximize' which would indicate that the checkbox is checked and that the popup menu is set to `zoom`.


I believe the value of `AppleActionOnDoubleClick` should be 'None' when the checkbox is not checked.

Radar report has been filed:

24094110


Thank you

Double-click a window's title bar to zoom/minimize bug on OS 10.11
 
 
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