Comment 11 for bug 1497170

Found the source of the issue. Previously, xfce was not did not use gvfs-info for mimetype detection. This changed in this commit:

http://cgit.freedesktop.org/xdg/xdg-utils/commit/?id=8392f94bbc640e4e69aae706d33a9e4a2f364f26

Relevant code: http://cgit.freedesktop.org/xdg/xdg-utils/tree/scripts/xdg-mime.in?id=5336e0a26dbd1e7cb00a8c05678fef039ba2c3db#n76

Before xfce used info_generic, which performs the mimetype lookup with the mimetype command instead of gvfs-info. On a newly created plaintext file:

$ mimetype --brief --dereference test
text/plain

$ gvfs-info test 2> /dev/null | grep standard::content-type | cut -d' ' -f4
application/octet-stream