Under certain conditions, the renderContent method will deterministically throw multiple IndexOutOfBoundsExceptions, which are silently discarded in a catch block. This impacts performance somewhat in these situations.

Reproduction steps:
- Run the latest monkey tester
- Set breakpoint to com.sun.javafx.sg.prism.NGGroup:262, the only catch block in the method
- Navigate to Tools -> System Info in monkey tester
- In the System Info text field, select some text with the mouse
- Multiple exceptions should be thrown

Caused by
startPos = -1

This issue occurs if both hscroll and vscroll bars are active in the TextArea. If only one scrollbar is showing, the issue does not occur. Any change in text selection will throw this exception.