1003680 - network.prefetch-next does not work

Status: RESOLVED INVALID

(Firefox :: General, defect)

Description

[Christopher]

User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release)
Build ID: 20140314220517

Steps to reproduce:

network.prefetch-next is disabeld on my OSX Machine...



Actual results:

While hovering over a Link , the link-prefetching is prefetching (little snitch says that firefox wants to connect to the website)


Expected results:

Nothing...

Comment 1

[:Gijs (he/him)]

Thanks for the report! This sounds pretty serious. Could you provide a simple HTML testcase?

Comment 2

[Christopher]

Attachment: testcase

Is that tastcase fine ?

Comment 3

[:Gijs (he/him)]

(In reply to Christopher from comment #2)
> Created attachment 8416329 [details]
> testcase
> 
> Is that tastcase fine ?

I can't reproduce with this testcase, that is, hovering the link does not show any new servers (for w3.org) showing up in Little Snitch's network monitor - irrespective of the value of the network.prefetch-next preference. Can you? Can you try if this happens if you restart with add-ons disabled?

Comment 4

[Christopher]

i already tried it with disabled addons and with a complete new profile (and directly disabeling the network.prefetch-next option) =/

Comment 5

[u485023]

In my tests, I could indeed notice FF checking links when mouse-hovering over them and having LittleSnitch Network monitor open. The URL in question does appear so FF is indeed pre-visiting that URL or checking something.

Comment 6

[:Gijs (he/him)]

(In reply to Foss from comment #5)
> In my tests, I could indeed notice FF checking links when mouse-hovering
> over them and having LittleSnitch Network monitor open. The URL in question
> does appear so FF is indeed pre-visiting that URL or checking something.

I see. This is strange, because I see nothing in little snitch and nothing in the browser console. I've tried other websites as well, and I don't see any prefetching (again, irrespective of the preference!). Just loading the testcase should be enough, right, or are you only seeing this if you've already visited the site, or if it's bookmarked, or something like that?

I actually only just noticed you reported this from 28. If you download 29 from http://www.mozilla.org/, is the behaviour any different for either of you?

Comment 7

[u485023]

:Confused: Firefox 29 final here. Had beta installed but switched channels as soon as the final was out. Actually reporting from Safari here. But tested FF29 with http://www.zerohedge.com/

If you hover between the "RanSquawk" and the "comments" section on the right side of that webpage, LS monitor shows activity.

Is that not reproducible for you?

Comment 8

[Christopher]

nah the 28 one is my machine at work (beside that ist an windwos machine). The disabeling of the network.prefetch-next option is working on windows...

But everythime I visit the testcase and hover over the link little snitch is triggert....

Comment 9

[:Gijs (he/him)]

(In reply to Foss from comment #7)
> :Confused: Firefox 29 final here. Had beta installed but switched channels
> as soon as the final was out. Actually reporting from Safari here. But
> tested FF29 with http://www.zerohedge.com/
> 
> If you hover between the "RanSquawk" and the "comments" section on the right
> side of that webpage, LS monitor shows activity.
> 
> Is that not reproducible for you?

I can reproduce with the zerohedge website, but not with attachment 8416329 [details].

Comment 10

[Christopher]

Well on the zerohedge website i have the same problem ...

Comment 11

[:Gijs (he/him)]

(In reply to Christopher from comment #10)
> Well on the zerohedge website i have the same problem ...

Right, but it'd be nice to have a simpler testcase, as well as to know why this happens on zerohedge but not on your testcase. :-\

Comment 12

[:Gijs (he/him)]

So... it turns out this isn't the prefetching facility that that pref controls (that pref governs whether sites' <link rel="next"> et al. stuff gets fetched) but it's the speculative connection code. This was implemented in bug 790882, and there was some discussion in bug 814169 about having a pref to disable the feature. The bug was wontfixed, so there isn't a simple on/off pref.

However, as bug 814169 comment 16 points out, you can set the following pref:

(In reply to Honza Bambas (:mayhemer) from comment #16)
> Try setting 'network.http.speculative-parallel-limit' to 0.

And I've verified that that stops the speculative connections.

That makes this bug as-is invalid. Gavin, I'm needinfo'ing you to check if we want to revisit bug 814169 in any way, as it seems there is a pref, and it works... maybe we should change it to WFM? :-)

Comment 13

[:Gavin Sharp [email: [e-mail]]]

The patch in that bug was proposing something somewhat different, so I think WONTFIX is most accurate, but the pref does exist as noted there.