Open Bug 1543990 Opened 8 months ago Updated 8 months ago

Regression in Firefox 66: <link rel="preconnect"> no longer working

Categories

(Core :: Networking, defect, P3)

66 Branch
Desktop
Windows 10
defect

Tracking

()

ASSIGNED

People

(Reporter: jakub.g.opensource, Assigned: dragana)

Details

(Whiteboard: [necko-triaged])

Attachments

(1 file)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0

Steps to reproduce:

Open https://jg-testpage.github.io/wpt/preconnect.html in Firefox 66

It contains <link rel="preconnect"> + setTimeout(1000) HTTP request

Actual results:

<link rel="preconnect"> was ignored, and DNS+TCP+TLS happened at the HTTP request time

From my tests with devtools it seems it was working until Firefox 65 (see attachment)

Expected results:

DNS+TCP+TLS should have happened earlier

Firefox 66 KO https://www.webpagetest.org/result/190411_12_ed5cfb727a48dcea11b1a4f54999922c/1/details/

Firefox 68 Nightly KO https://www.webpagetest.org/result/190411_T3_3cb066d3ceb1fbd2be1bf33cfb491bf5/1/details/

Chrome OK https://www.webpagetest.org/result/190412_AQ_147b2535813e4324497d471e22d67445/1/details/

Component: Untriaged → Networking
OS: Unspecified → Windows 10
Product: Firefox → Core
Hardware: Unspecified → Desktop

Hmm it seems to be KO also on Firefox 60 ESR on WebPageTest which is quite surprising to me:

https://www.webpagetest.org/result/190412_VW_914427d9be5121b7bab6fac7c054ea64/1/details/#waterfall_view_step1

I was thinking that since Firefox ESR always reports "60.0" in useragent string, it could be that WPT has ESR v60.6 which may contain the faulty code from Firefox 66, but I tested 60.6 ESR locally and it is not affected.

Assignee: nobody → dd.mozilla
Status: UNCONFIRMED → ASSIGNED
Ever confirmed: true
Priority: -- → P3
Whiteboard: [necko-triaged]
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