g_locale_from_utf8 on Windows fails to handle code points above U+0100
Submitted by Devin Acker
Test program: https://gist.github.com/devinacker/cd09eb2ab4608b3d90f1 (compiled as UTF-8 using MinGW)
In the above test program (as well as Windows builds of HexChat, which is how I originally discovered the issue), attempting to call g_locale_from_utf8 with a string containing only Unicode code points below U+0100 returns an appropriately translated string, while higher code points (such as the Japanese text in the test program) result in the error "Invalid byte sequence in conversion input", even when the actual UTF-8 byte sequence appears to be completely valid.
I have tested this repeatedly with various combinations of non-ASCII characters both above and below U+0100 and gotten the same results, on both Windows 7 and 8, with the system locale set to English (United States).