clean backport of 8244234: MenuButton: NPE on removing from scene with open popup Reviewed-by: aghaisas
------------- Commit messages: - 8244234: MenuButton: NPE on removing from scene with open popup Changes: https://git.openjdk.org/jfx17u/pull/69/files Webrev: https://webrevs.openjdk.org/?repo=jfx17u&pr=69&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8244234 Stats: 131 lines in 2 files changed: 126 ins; 1 del; 4 mod Patch: https://git.openjdk.org/jfx17u/pull/69.diff Fetch: git fetch https://git.openjdk.org/jfx17u pull/69/head:pull/69 PR: https://git.openjdk.org/jfx17u/pull/69
