Apologies for totally blowing that last message...
I should have mentioned that: I'm using xdg-icon-resource to install a 48x48 png in the hicolor theme, so located atWhere is your icon installed ? most likely, what you are seeing is a side-effect of the fallback algorithm in the icon theme spec: if you specify multiple names like that, it tries to find any of those in the current theme before falling back to an inherited theme. So, if gnome-icon-theme has application-x-executable, and you install application-t4l-pixie into hicolor, then you'll still get application-x-executable when the gnome icon theme is current.
/usr/share/icons/hicolor/48x48/mimetypes/application-t4l-pixie.png The chosen icon is located at /usr/share/icons/gnome/scalable/mimetypes/application-x-executable.svgThe list is reasonable for fallbacks (file is executable), but how can I ensure my icon is chosen for all themes (that don't override this specific type)?
Thanks for your reply, michael Asides:If I switch the executable bit, the list becomes application-t4l-pixie, application-x-generic, text-x-generic, with the text icon chosen.
For what it's worth, using gnome_icon_lookup in libgnomeui instead of the gio methods gives my icon.