Since tear uses libcurl, it supports http_proxy environment variable, so it is useful for people who need a constant proxy. Just run in xterm

export http_proxy=http://localhost:8118/
tear

To get tear to use a proxy.

This does not help if you want to config proxy by hand.

If you want tear to use the proxy settings from connection manager, you need to convert the following line to vala syntax and add it in a certain strategic place in the code:

if (ConIc.ProxyMode==NONE)
Environment.g_unsetenv("http_proxy");
else
Environment.g_setenv("http_proxy", "http://" + ConIc.get_proxy_host(HTTP) + ":" + ConIc.get_proxy_port(HTTP) + "/");