g_win32_locale_filename_from_utf8() failed to convert a local path

Submitted by Jehan @Jehan

Link to original bug (#795006)

Description

In GIMP, bug 794949, we had a case on Windows with an image with a path such as "F:\都.png". We needed to load metadata with GExiv2, which unfortunately doesn't have support for GFile or GInputStream/GOutputStream yet (cf. bug 732748).

So we passed the result of g_file_get_path() in g_win32_locale_filename_from_utf8(). Unfortunately it failed and returned NULL (for the record, g_file_get_path() properly returned a valid UTF-8 value as far as we could see).

So I read the function docs which says it may fail when the string contains unicode characters not representable in the system codepage. Yet since this is the path of an actual file currently existing in the filesystem, I assume it should be convertible in the system codepage, so that would be a bug. Or am I misunderstanding something?

Version: 2.55.x