Created attachment 142417 [details]
Screenshot with Syriac text

Justifying a paragraph in LibreOffice Writer with text written in the Syriac script (Unicode block U+0700-U+074F) creates graphic clutter between every word. See the attached screenshot where the first paragraph is justified and the second is right-aligned. The second paragraph looks as it should, whereas the first paragraph shows a small line added at the end of each word. If you zoom in or out, some of the lines may disappear, but when you create a PDF, they are all there.

The same problem occurs with nearly all the Syriac fonts I have tried, including Serto Batnan, Estrangelo Antioch, East Syriac Ctesiphon and Serto Urhoy (all part of the ttf-xfree86-nonfree-syriac Debian package, also available through www.bethmardutho.org). For the last two, the clutter is not visible on screen but shows up if you create a PDF. With East Syriac Adiabene, the problem doesn't seem to occur. Sometimes the same problem occurs with Arabic text, as well. See the attached screenshots, PDFs and the documents used to create them.

Another user on Launchpad confirmed that the same problem persists in LibreOffice 6.0.3.2.

This bug was first reported on Launchpad at https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/1772414