Description of problem:
1/2 xdg-email doesn't detect thunderbird as default email client because there is a typo in xdg-mail in open-gnome3 where it is currently...
client=`desktop_file_to_binary "$browser"`
and it should be
client=`desktop_file_to_binary "$desktop"`

2/2 xdg-email doesn't detect thunderbird as default email client because it uses
xdg-mime query default x-scheme-handler/mailto
which returns "evolution"
but however
gvfs-mime --query x-scheme-handler/mailto
does return "thunderbird"

I'm not sure where the bug is there, but my gnome3 settings lists thunderbird as the default so thats the expected result

xdg-email will eventually launch thunderbird anyway because it hands it off to another program to find the email client, but because it doesn't know that the email client is thunderbird it doesn't use its built-in special case for thunderbird to enable adding attachments to thunderbird

Version-Release number of selected component (if applicable):
1.1.0-0.16.20120809git.el7

How reproducible:
100%

Steps to Reproduce:
1. export XDG_UTILS_DEBUG_LEVEL=10
2. touch /tmp/foo.txt && xdg-email "mailto:?subject=noname&attach=file:///tmp/foo.txt"


Actual results:
thunderbird starts with no attachment

Expected results:
we get an attachment

Additional info:
The use case is file->send->email document from LibreOffice calc