Lazarus supports these ISO encodings
iso-8859-1
iso-8859-2
iso-8859-15
but it missed your case iso-8859-9. maybe sometimes one appears who will add 'your case' too.
yes I know that you suggest to parse XML line, but it's no help now.
All XML files (about 6 different files) I tested with ISO-8859-9 encoding works just fine.
I made an UTF8 encoded XML file, copied it to a different name just to make it a newly opened file for CudaText and that file is also correctly opened as UTF8 encoding.
This encoding is mapping to cp1254 in CudaText as to my knowledge. I wonder if it is possible to add it in auto encoding setting of XML files.
I could not check cp1254 encoding as I failed to change encoding of auto encoded XML file
Attached is a small video to explain what I mean. This is version 1.161.0.0 win64-x86_64 version I am using.
I repeat my reply from email.
I tested your file and _clean_ Cud opens it in cp1254. Not utf8. Can you pls test on _clean Cud_? if no problem there, add your plugins, 1 by 1, and see again.