Mirror shape on right-to-left sheet?

[Regina Henschel]

Hi all,

Start Calc and set the sheet to right-to-left (complex text layout 
enabled, menu Format).
Insert left-to-right arrow, one cell anchored, another page anchored.
Save to .ods and open archive.
Examine element draw:enhanced-geometry. There is no attribute 
'draw:mirror-horizontal' which means default value "false".

Now do the same in Excel. Excel writes 'draw:mirror-horizontal="true"'.

Open the file which was saved by LibreOffice. Notice that the page 
anchored arrow is flipped. That is bug 137081. To fix it, I need to 
know, what is the correct attribute in file format.

Kind regards
Regina