When `getAllPrinterNames()` returns null, the list of `printServices` is assigned a new empty array without invalidating old services which were in the array before.
The old print services should be invalidated. ------------- Commit messages: - 8263984: Invalidate printServices when there are no printers Changes: https://git.openjdk.java.net/jdk/pull/3151/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3151&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8263984 Stats: 8 lines in 1 file changed: 6 ins; 1 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/3151.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3151/head:pull/3151 PR: https://git.openjdk.java.net/jdk/pull/3151
