Acquire::http::ProxyAutoDetect is executed multiple times for each host

[Peter Wu]

For each host that is involved in an update/ installation, APT executes the command set in Acquire::http::ProxyAutoDetect. On a default installation, sudo apt-get update executed the command twice because archive.ubuntu.com and security.ubuntu.com are both mentioned in /etc/apt/sources.conf. As PPAs are commonly used, this increases to three.
With a lot of third-party repository sources, this number rises a lot. If the proxy detection command is slow, there might be a delay during the source lists updates and package installations.

Affected versions:
0.8.13.2ubuntu4.1 (Ubuntu Natty)
0.7.25.3ubuntu9.5 (Ubuntu Lucid)
0.8.15.2 (Debian unstable)

Steps to reproduce:
1. Create /etc/apt/print-message containing:
#!/bin/sh
echo CALLED >&2
2. Create /etc/apt/apt.conf.d/30proxy-test containing:
Acquire::http::ProxyAutoDetect "/etc/apt/print-message";
3. Run sudo apt-get update or install a PPA package which depends on a package from the official repos which is not installed yet
4. Clean up by removing /etc/apt/apt.conf.d/30proxy-test and /etc/apt/print-message

What I expected to happen:
CALLED should be printed once

What happened instead:
CALLED is printed a few times for each involved host.

[Torsten Spindler (tspindler)]

I can confirm the multiple calls for the ProxyAutoDetect script, following your setup above. I believe proxies can be set for different sources, so I think the auto-detect needs to run for any new source. I mark this bug as wishlist item.

[dino99 (9d9)]

Support for this version has ended