A case of Connection: keep-alive, Upgrade

[xinyanglbeijing@…]

nginx -v
1.14

kernel
Linux ubuntu1804-dev-server-xinyang 4.15.0-20-generic #21-Ubuntu SMP Tue Apr 24 06:16:15 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Description:
This case happened when I used firefox to get a websocket connection.
If I uses chrome that works well.

Below is the http traffic.

Chrome (Works)
GET URL HTTP/1.1
Host: host
Connection: Upgrade <------------------ upgrade is in a separated line
Pragma: no-cache
Cache-Control: no-cache
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36
Upgrade: websocket
Origin: URI
Sec-WebSocket-Version: 13
Accept-Encoding: gzip, deflate
Accept-Language: en
Cookie: XXX
Sec-WebSocket-Key: XXXX
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits

===========================================================================

Firefox (doesn't work)
GET URI HTTP/1.1
Host: host
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Sec-WebSocket-Version: 13
Origin: XXXX
Sec-WebSocket-Extensions: permessage-deflate
Sec-WebSocket-Key: XXXX
DNT: 1
Connection: keep-alive, Upgrade <------------------------- Here multiple values are in one line
Cookie: XXXX
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket