Some fonts, e.g. http://wiki.irmug.com/index.php/X_Series_2, contain both OpenType and AAT (Apple Advanced Typography) layout, and currently AAT takes precedence. For Arabic fonts, using AAT, causes bug 155531, so one solution for hybrid fonts is to force OpenType layout. This, however, requires changes in HarfBuzz (https://github.com/harfbuzz/harfbuzz/issues/4108), so this issue is to track the LibreOffice side of this once HarfBuzz has the required support.
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