Yet it's exactly what's happening now: the system changes from headful
to headless… and back to headful.
On 2026-03-30 21:05, Philip Race wrote:
Also making it a bit of a tricky one in that "headless" isn't designed
to be something that changes during the life of the application.
Before https://bugs.openjdk.org/browse/JDK-8185862, it was assumed a
display always exists. However, it wasn't always the case, and it caused
the assertion in AWT.
The assertion may have appeared after a while, too. To silence the
assertion, the code in JDK-8185862 detects whether there are monitors
connected to the system. If there are none, it switches to headless mode.
As the subsequent bug reports show, the state can change while a Java
application is running: the connected monitors could disappear when a
(user) session is disconnected; monitors could then reappear when a
session gets connected again.
I still wonder why this behaviour isn't reproducible all the time, though…
--
Regards,
Alexey
