A DESCRIPTION OF THE PROBLEM :
In standard text editors the entire row is selected when triple-clicking a row with the mouse. By "entire row" I here mean that the eol characters are included in the selection. This is not the case for the new RichTextArea.
Triple-clicking and doing ctrl-X will leave and empty row behind and the cut text does not have the eol included.
This is reported as a bug since this is standard behavior in text editors, including the standard TextArea component in JavaFX.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a window with a RichTextArea, triple-click the line, not that there is a blank row left in the window. Paste the text into a different text editor. Note that there is no line break at the end.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
EOL characters are included in the triple-click selection.
ACTUAL -
EOL characters are not included in the triple-click selection.