Comment 6 for bug 1002113

Mint 15 MATE 64-bit for which Firefox is the default, but I set Chromium to be so in Preferred Applications.
$ xdg-mime query default x-scheme-handler/http
$ xdg-mime query default x-scheme-handler/https
both report back: chromium-browser.desktop which is as it should be, but links are opening from LibreOffice in Firefox.

gksudo pluma /etc/gnome/defaults.list
shows at the end of that file:
x-scheme-handler/http=firefox.desktop
so I replaced firefox with chromium:
x-scheme-handler/http=chromium.desktop
but still http links open in Firefox, so I give up for now...