Description:
When LO opens a dialogue menu (e.g. after a Close Window command) one box should be highlighted (in this example "SAVE"). But instead, LO highlights ALL boxes.  

Steps to Reproduce:
1.Open a file
2.Change it
3.Select File > Close Window
4. Press Enter


Actual Results:  
dialogue box appears. All three boxes (Dont't Save / Abort / Save) are highlighted. After hitting the Enter key, LO closes the window without saving the file.

Expected Results:
Box "Save" should be highlighted. Hitting "Enter" should make LO save the file before closing the window. 


Reproducible: Always


User Profile Reset: Yes



Additional Info:
I *think* I observed this bug first in LO 5.4. but am not quite sure. It is definitely there in this version, also in LO 6 rc.


User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:57.0) Gecko/20100101 Firefox/57.0