User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0
Steps to reproduce:
We use a "proxy.pac" file which sets a specific proxy "localhost:3128" (which is a port forwarded by putty) for specific webpages.
This proxy is only needed, if user is outside of LAN and only in that case putty is running and the "localhost:3128" port is available.
Up to Firefox version 64.0.2 this worked fine: In LAN Proxy "localhost:3128" failed, so after first try Firefox switched to DIRECT and worked with very good speed.
But starting with 65.0.0 in that case a delay is added with every network connection. Browsing is very slow now, when the first proxy is not available.
Up to now we did not roll out versions higher than 64.0.2 because of this. But now we have to because of the AddOn issue fixed in version 66.0.4... :(
The proxy.pac looks like this:
function FindProxyForURL(url, host)
var proxy = "PROXY localhost:3128; DIRECT";
var no_proxy = "DIRECT";
if (dnsDomainIs(host, ".xycorp")
A delay of ~1..2 seconds is added on every connection. Web browsing feels very slow, if the first proxy configured is not available.
If the first proxy is not available Firefox should use the second proxy (in out case DIRECT) and work fast as usual.