Exception in Application stop method in 1.7.19

[RazmikDev]

Application with NoPrimaryViewSpecified as primaryView fails on shutdown (App.stop()) with following exception:

java.lang.RuntimeException: Exception in Application stop method
	at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:922)
	at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: root.scene must not be null
	at tornadofx.UIComponent.unInit(Component.kt:575)
	at tornadofx.App.stop(App.kt:140)

that occurs here

tornadofx/src/main/java/tornadofx/Component.kt

Line 575 in e6258f0

root.scene.window.showingProperty().removeListener(rootSceneWindowShowingPropertyChangeListener)

Valid only for v1.7.19 - might be related with #973

[carltonwhitehead]

@RazmikDev I agree with your suspicion that it's related to #973. I made some adjustments including that line and didn't think to test NoPrimaryViewSpecified scenario. Sorry about that! I'll add a test for that scenario and fix the bug.

[edvin]

Thank you @carltonwhitehead :)