Comment 4 for bug 504075

It turns out that this bug is a manifestation of a bug in libsoup-gnome2.4-1:

    Bug: #433827 Regression: "Automatic proxy configuration" + gnome-terminal now breaks apt-get, curl, wget...

in libsoup/soup-proxy-resolver-gnome.c:

        } else if (proxy_mode == SOUP_PROXY_RESOLVER_GNOME_MODE_AUTO) {
                char *autoconfig_url;

                autoconfig_url = gconf_client_get_string (
                        gconf_client, SOUP_GCONF_PROXY_AUTOCONFIG_URL, NULL);
                if (autoconfig_url && !strncmp (autoconfig_url, "http", 4))
                        http_proxy = g_strconcat ("pac+", autoconfig_url, NULL);
                else
                        http_proxy = g_strdup ("wpad://");
                g_free (autoconfig_url);

So, in Gnome network proxy settings, if we set the automatic proxy URL to http://wpad.example.org/wpad.dat, we get http_proxy=pac+http://wpad.example.org/wpad.dat .

Otherwise, if we set the automatic proxy URL to e.g. file:///etc/proxy.pac, we get http_proxy=wpad:// .

This bug has been reported to the upstream author: https://bugzilla.gnome.org/show_bug.cgi?id=603285 , though I think a bit of convincing is necessary, as setting the http_proxy= to these pac+http:// or wpad:// stuff is just *wrong* IMHO, especially because it breaks 90% of the existing programs out there.