Installing GDebi ruins apt links

When you installs gdebi, it is set to open x-scheme-handler/apt. You can see setting from /etc/gnome/defaults.list

$ cat /etc/gnome/defaults.list | grep apt
x-scheme-handler/apt=gdebi.desktop

If you want to change in order to open again with AptUrl then replace gdebi.desktop with apturl.desktop for x-scheme-handler/apt:

1. Open /etc/gnome/defaults.list by `sudo gedit /etc/gnome/defaults.list` (be careful as sudo)
2. Replace x-scheme-handler/apt=gdebi.desktop with x-scheme-handler/apt=apturl.desktop
3. Save file and exit

Now apt links handled with apturl.

Alternatively you may run following command:
sed 's/x-scheme-handler\/apt=gdebi.desktop/x-scheme-handler\/apt=apturl.desktop/' /etc/gnome/defaults.list | sudo tee /etc/gnome/defaults.list

Another user gets bitten by this

https://trisquel.info/en/forum/abrowser-install-gnu-icecat-link-issue#comment-90727

try executing:
xdg-mime default apturl.desktop x-scheme-handler/apt

buttttt....

Gdebi doesn't have functionality of opening apt: links, however apturl does.There is a way to set default application for x-scheme-handler links with xdg-mime command.

First make sure apturl is installed on your system,

sudo apt-get install apturl

Latest version of chromium already uses xdg-open for any x-scheme-handler links.To configure xdg-open with apturl , go through following steps:

Make sure they are all set correctly:

Hit Alt+F2
Enter gconf-editor
Navigate to the /desktop/gnome/url-handlers/apt/command, it should be set to apturl "%s".

Now set apturl default for any apt links:

xdg-mime default apturl.desktop x-scheme-handler/apt

It will set apturl as default application for apt links.You can check it by running xdg-mime query default x-scheme-handler/apt in the terminal(output would be apturl.desktop)

Now whenever you click apt in chromium, it will use apturl.