The bold and italic fonts for arabic text are not rendered and hence, instead of characters only boxes are displayed in pdf (see attachment).
Note: mwlib runs as a standalone server, print on demand is disabled ($wgCollectionPODPartners = false).
Mediawiki: 1.31
Collection extension: 1.7.0
mwlib: 0.15.19
mwlib-rl: 0.14.6
Here the original page to reproduce the problem:
https://wiki.uni-konstanz.de/transmed-ar/index.php/%D9%A6%D9%A2%D9%A1:_%D8%A5%D9%8A%D8%B2%D9%8A%D8%AF%D9%88%D8%B1_%D8%A7%D9%84%D8%A7%D8%B4%D8%A8%D9%8A%D9%84%D9%8A_%D8%AD%D9%88%D9%84_%D8%A3%D8%B5%D9%84_%D9%85%D8%B5%D8%B7%D9%84%D8%AD_%22%D8%A7%D9%84%D8%B3%D8%B1%D8%A7%D8%B3%D9%8A%D9%86%22
The following fonts are used for arabic PDF document:
$ pdffonts ar.pdf name type encoding emb sub uni object ID ------------------------------------ ----------------- ---------------- --- --- --- --------- AAAAAA+FreeSerif TrueType WinAnsi yes yes yes 14 0 AAAAAB+FreeSerif TrueType WinAnsi yes yes yes 18 0 AAAAAA+FreeSerifBold TrueType WinAnsi yes yes yes 22 0 Helvetica Type 1 WinAnsi no no no 2 0 AAAAAA+FreeSerifItalic TrueType WinAnsi yes yes yes 26 0 AAAAAA+FreeSans TrueType WinAnsi yes yes yes 30 0
The corresponding page in german shows the fonts correctly, here the original page:
https://wiki.uni-konstanz.de/transmed-de/index.php/711:_Ibn_%CA%BFAbd_al-%E1%B8%A4akam_zur_Kollaboration_Julians_bei_der_muslimischen_Invasion_der_Iberischen_Halbinsel
The german PDF file uses additional fonts (FreeSansBold and FreeSansOblique):
$ pdffonts de.pdf name type encoding emb sub uni object ID ------------------------------------ ----------------- ---------------- --- --- --- --------- AAAAAA+FreeSerif TrueType WinAnsi yes yes yes 28 0 AAAAAA+FreeSerifBold TrueType WinAnsi yes yes yes 32 0 AAAAAA+FreeSansBold TrueType WinAnsi yes yes yes 36 0 Helvetica Type 1 WinAnsi no no no 2 0 AAAAAA+FreeSans TrueType WinAnsi yes yes yes 40 0 AAAAAA+FreeSerifItalic TrueType WinAnsi yes yes yes 44 0 AAAAAA+FreeSansOblique TrueType WinAnsi yes yes yes 48 0