I’m going to have to say no on this for now, for two reasons:

• There are people doing ongoing work on util/cdrom.cpp, and this would interfere with it.
• The “text mode” features of util::core_file are in a pretty dreadful state to begin with.

I realise it’s a real issue, but people will have to work around it for a while longer. Also note that all the Lua scripts that use LFS (Lua File System) and/or standard Lua file objects have issues when paths can’t be represented in the current code page. There are a few other things that use std::ifstream and std::ofstream in the codebase as well.

I was planning to get rid of the stuff using std::ofstream sooner by writing a stream buffer implementation that uses the stuff from ioprocs.h as a backend. That would also allow the text mode writing features to be removed from util::core_file. Dealing with the stuff that needs to read text files is more complicated.