Can just Luatex ask some C library IO function to open the name it was passed in, without it trying to be too smart parsing the name? The opposite. Windows command shell passes accented letters in DOS 8-bit encoding (prehistoric, don't you see?). So, if LuaTeX were extremely pedantic, he could convert these characters to UTF-16, which is actually how filenames are stored in the filesystem. And just in cases, when the input comes directly from the terminal. At
On 2013-12-03 12:05, Javier Múgica de Rivera wrote: the moment LuaTeX is quite simple and clear about any input – UTF-8. May be solution could be using of .bat files, where command lines are put in UTF-8? Just guess. You could try Cygwin terminal as well – it uses UTF-8 for the input. What about Total Commander? Don't have it at the moment.
Not being able to write accents or other kinds of characters in the filename is a déja-vu form the protohistory of informatics. Think about filenames like some kind of names of variables. Do you experience any discomfort about lack of accents on them? Is the case really very first time, you have problems with accented filenames? Especially across different filesystems, like Hans mentioned?
Mindaugas.