Fixing IndexOutOfBoundsException in the MultipleSelectionModelBase and added a unit-test for it. ticket: https://bugs.openjdk.java.net/browse/JDK-8256397 run test: `./gradlew --continue -PFULL_TEST=true controls:test --tests "*MultipleSelectionModelImplTest*"`
------------- Commit messages: - 8256397 Changes: https://git.openjdk.java.net/jfx/pull/353/files Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=353&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8256397 Stats: 24 lines in 2 files changed: 23 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jfx/pull/353.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/353/head:pull/353 PR: https://git.openjdk.java.net/jfx/pull/353
