--proxy-pac-url option is ignored

[rany2]

Description

--proxy-pac-url=http://wpad/wpad.dat is ignored.

How to Reproduce?

1. verify via curl http://wpad/wpad.dat that proxy autoconfig data is valid.
2. launch flatpak run org.chromium.Chromium --proxy-pac-url=http://wpad/wpad.dat
3. open http://ip4.me or any other similar site that displays IP address

Actual behaviour

Shows actual IP address.

Expected behaviour

Shows proxy IP address.

Relevant log output

Repeat same steps using /usr/bin/chromium-browser --proxy-pac-url=http://wpad/wpad.dat and observe that proxy IP is returned.

Notes

• I initially suspected that this was occurring because wpad was failing to resolve, however isn't the case as the same problem occurs when substituting wpad with the proxy server's IP.
• The original thread is available at https://github.com/flathub/com.github.Eloston.UngoogledChromium/issues/129