Falls over on the fact that I don’t want to be able to write these two files in the same dir. if I write file ö1.txt and ö1.txt then I want to be warned that th

Falls over on the fact that I don’t want to be able to write these two files in the same dir. if I write file ö1.txt and ö1.txt then I want to be warned that the file exists even of the encoding is different when I use two different apps but try to write the same file. The same applies for a.txt and A.txt on case insensitive file systems (as someone pointed out the most common desktop file systems are).