Description:
In LibreOffice Writer, when you create a document and try to add borders to its four sides using the "Thin Thick, Medium Gap" line style and with the "Extra thick (4.5pt)" Thickness the inside thin lines don't meet well at the corners. 
It does not work for other gaps or thickness using the "Thin Thick" line styles (Small Gap, Large Gap, Thick (2.25pt), etc.)
The "Thick Thin" line style seems to work in all cases.


Steps to Reproduce:
1.Open a new document
2.Edit the page style (Shift Alt P)
3.Select 4 borders, line style "Thin Thick Medium Gap" for instance, with Thickness "Extra thick (4.5pt)" for instance and observe the result at each of the corners by zooming in on them.

Actual Results:
The inside thin lines of the border don't meet square, one is longer than should be.

Expected Results:
The inside thin lines should meet at a miter to make a square corner.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
It would be nice to have the name of the selected line style appear on the side of the drop box, also because the selection is not easy in this drop box, the lines are too close and you have to wait for the tool tip to appear to know what is under the mouse selection.