The assertions reported in the bug were observed spuriously and here and there broke tests in some Windows configurations. For instance [JDK-8266129](https://bugs.openjdk.org/browse/JDK-8266129), [JDK-8269529](https://bugs.openjdk.org/browse/JDK-8269529) or [JDK-8323664](https://bugs.openjdk.org/browse/JDK-8323664) came up due to this.
The problem is that in Windows environments without a valid display, e.g. started by system services or via PowerShell Remoting, one sees a Monitor with name 'Windisc' in `EnumDisplayMonitors`. However, it seems to be some kind of a pseudo device where you can not get a DC via `CreateDC`. This behavior/monitor type doesn't seem to be well documented, though. I hereby modify the device initialization code to only count/detect monitors where CreateDC returns non-NULL in Devices.cpp. I also add some more checking/error handling to AwtWin32GraphicsDevice::Initialize() for correctness. Furthermore, I re-enable the test `javax/swing/reliability/HangDuringStaticInitialization.java` for Windows Debug VMs, which reverts the fix from JDK-8269529 that should not be necessary any more. ------------- Commit messages: - JDK-8185862 Changes: https://git.openjdk.org/jdk/pull/17614/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17614&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8185862 Stats: 60 lines in 3 files changed: 34 ins; 13 del; 13 mod Patch: https://git.openjdk.org/jdk/pull/17614.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/17614/head:pull/17614 PR: https://git.openjdk.org/jdk/pull/17614
