The bug occurs when showRoot is set to false on a root with no children, the expanded item count drops is 0 causing `isFocused(0)` to return false even though `focusedIndex` is still 0. When items are added afterwards the `treeItemListener` sees `focusedIndex=0` and incorrectly shifts it to 1 placing the focus on second item of the `TreeTableView`. The fix replaces `isFocused(0)` with `getFocusedIndex() >= 0`, which reads the raw stored index.
------------- Commit messages: - Minor changes - Fix TreeTableView focus and added test Changes: https://git.openjdk.org/jfx/pull/2104/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=2104&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8379662 Stats: 130 lines in 2 files changed: 127 ins; 0 del; 3 mod Patch: https://git.openjdk.org/jfx/pull/2104.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/2104/head:pull/2104 PR: https://git.openjdk.org/jfx/pull/2104
