Open Radar

 
An application has an NSStatusItem with a tooltip; the application is initially a UIElement (its activation policy is Accessory), but clicking the status item sets the activation policy to Regular in order to display a dock icon and window. On closing the window, the application's activation policy is set back to Accessory to hide the dock icon; however, unexpectedly the status item's tooltip is no longer displayed by the system when pointing at the status item. This unexpected behavior continues until the next time the application's activation policy is set to Regular (or, oddly, until the application's process is attached by the Xcode debugger).

Steps to reproduce:
1) Build and launch the application in the attached project.
2) Point to the application's status item (a starburst icon) and observe that a tooltip is displayed.
3) Click the application's status item, and observe that the application opens a window and an icon appears in the dock as its activation policy is set to Regular.
4) Close the application's window (without clicking the Quit button), which hides the application window and sets the activation policy back to Accessory; observe that the application's dock icon disappears.
5) Point to the application's status item again.

Expected behavior:
The status item's tooltip is displayed.

Observed behavior:
The status item's tooltip is not displayed.  (It can be made to reappear only by clicking
the status item again, bringing the application back to the dock.)

This has been observed in both OS X 10.10.5 (14F1509) and 10.11.2 (15C50).
No workaround is known.