FULL PRODUCT VERSION :
java version "1.8.0_144"
Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 10.0.15063]
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
When a row is removed from a TreeView hierarchy, the selection can incorrectly move. In my case, this seems to happen when the removed item is a sibling of the selected item's ancestor, and the removed item is in a lower row than the selected item. Debugging the TreeView class suggests that in the EventHandler treeItemListener, variable startRow is not being calculated properly.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
See test case

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
When we delete a row that is lower than the currently selected row, neither the selection nor the selection index should change. Test case below should pass.
ACTUAL -
Both selection and selection index change. Test case below fails both assertions.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No error

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
@Test
  public void testRemoveTreeItemShiftSelection(){
    TreeItem<String> a, b, a1, a2, a3;
    TreeItem<String> root = new TreeItem<>("root");
    root.getChildren().addAll(
        a = new TreeItem<>("a"),
        b = new TreeItem<>("b")
    );
    root.setExpanded(true);

    a.getChildren().addAll(
        a1 = new TreeItem<>("a1"),
        a2 = new TreeItem<>("a2"),
        a3 = new TreeItem<>("a3")
    );
    a.setExpanded(true);

    TreeView<String> stringTreeView = new TreeView<>(root);
    stringTreeView.setShowRoot(false);
    SelectionModel sm = stringTreeView.getSelectionModel();

    //rows:
    //a
    //a1
    //a2
    //a3
    //b

    sm.clearAndSelect(3); //select a3
    assertEquals(a3, sm.getSelectedItem()); //verify
    root.getChildren().remove(b); //remove b
    //a3 should remain selected
    assertEquals(3, sm.getSelectedIndex());
    assertEquals(a3, sm.getSelectedItem());
  }
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Workaround is to manually sync the selected row to the selected item in the business logic.