Stage.showAndWait(), which is implemented using nested event loops in Glass, is specified to return from showAndWait() after the stage has been hidden (which will terminate the nested event loop) and the event being processed returns to the event loop. The event loop should exit, causing showAndWait() to return before any subsequent events are processed.

While writing / updating the unit test for this, I discovered that while this works as expected on Windows, it does not work correctly on Mac (or Linux).

The attached ShowAndWaitTest.java test program, which is an updated version of the existing unit test in rt-closed/tests/app-lifecycle/LifeCycleTests/test/javafx/stage/ , will reproduce this bug. I haven't pushed the updated version to the repo yet.