1162641 - Netmonitor sometimes doesn't stay pinned to bottom

Status: NEW

(DevTools :: Netmonitor, defect)

Description

[Stephen Donner [:stephend] Not actively reading bugmail]

Build identifier: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:40.0) Gecko/20100101 Firefox/40.0

STR:

1. Tools | Web Developer | Network
2. Load www.mozilla.org
3. Watch the position of the scrollbar grabber/position-indicator
4. Reload the page or navigate to a new one
5. Notice the scrollbar's position sometimes/often changes (scrolls upwards)

Actual Results:

The grabber/scroll-position indicator often scrolls upwards

Expected Results:

It should persist its position (my use-case is opening the Web Console and seeing the GETs and POSTS in real-time as I test sites)

FWIW, this works fine in Firefox 37.0.2 on both Mac and Windows

Comment 1

[Brian Grinstead [:bgrins]]

(In reply to Stephen Donner [:stephend] from comment #0)
> STR:
> 
> 1. Tools | Web Developer | Network
> 2. Load www.mozilla.org
> 3. Watch the position of the scrollbar grabber/position-indicator
> 4. Reload the page or navigate to a new one
> 5. Notice the scrollbar's position sometimes/often changes (scrolls upwards)
> 
> Actual Results:
> 
> The grabber/scroll-position indicator often scrolls upwards
> 
> Expected Results:
> 
> It should persist its position (my use-case is opening the Web Console and
> seeing the GETs and POSTS in real-time as I test sites)

Is this an issue in the Network monitor or console?  Both are mentioned in the STR.

Both of those tools are designed to continually scroll down as new content comes in.  If you scroll manaully (or select a request in the netmonitor), it will stop doing that.  If I understand the report correctly, the content is staying still but the scrollbar is jumping around?

Comment 2

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to Brian Grinstead [:bgrins] from comment #1)

<snip>
 
> Is this an issue in the Network monitor or console?  Both are mentioned in
> the STR.

Apologies for conflating the two -- I meant the "Network" monitor, specifically.

> 
> Both of those tools are designed to continually scroll down as new content
> comes in.  If you scroll manaully (or select a request in the netmonitor),
> it will stop doing that.  If I understand the report correctly, the content
> is staying still but the scrollbar is jumping around?

Mostly (sorry, it's really hard to describe - let me get a screencast posted, next).

Looks like once the "initial" page load completes, any further AJAX/WebSocket requests cause the scrollbar to jump, but, yes: the same bottom entry persists while all that's happening above it (scrollbar jumping, other requests piling on, above the bottom entry).

Comment 3

[Stephen Donner [:stephend] Not actively reading bugmail]

Here's a screencast, comparing the differing behaviors in Firefox nightly with Firefox 37, on Windows: http://screencast.com/t/QPMXoLp7z

Comment 4

[Brian Grinstead [:bgrins]]

(In reply to Stephen Donner [:stephend] from comment #3)
> Here's a screencast, comparing the differing behaviors in Firefox nightly
> with Firefox 37, on Windows: http://screencast.com/t/QPMXoLp7z

I see.. when you clicked on the 'For Android' link it didn't continue the 'pin to bottom' feature.  Which version of Firebug are you using?

Comment 5

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to Brian Grinstead [:bgrins] from comment #4)
> (In reply to Stephen Donner [:stephend] from comment #3)
> > Here's a screencast, comparing the differing behaviors in Firefox nightly
> > with Firefox 37, on Windows: http://screencast.com/t/QPMXoLp7z
> 
> I see.. when you clicked on the 'For Android' link it didn't continue the
> 'pin to bottom' feature.  Which version of Firebug are you using?

Firebug 3.0.0-alpha.12

Comment 6

[Brian Grinstead [:bgrins]]

(In reply to Stephen Donner [:stephend] from comment #5)
> (In reply to Brian Grinstead [:bgrins] from comment #4)
> > (In reply to Stephen Donner [:stephend] from comment #3)
> > > Here's a screencast, comparing the differing behaviors in Firefox nightly
> > > with Firefox 37, on Windows: http://screencast.com/t/QPMXoLp7z
> > 
> > I see.. when you clicked on the 'For Android' link it didn't continue the
> > 'pin to bottom' feature.  Which version of Firebug are you using?
> 
> Firebug 3.0.0-alpha.12

OK thanks, and do you have e10s enabled?

Comment 7

[Brian Grinstead [:bgrins]]

Honza, I've been unable to reproduce without Firebug 3 installed but with the latest alpha I see this bug.  Should we move this into the Firebug issue tracker? 

STR:
Open https://www.mozilla.org/en-US/firefox/desktop/
Open netmonitor (Firebug)
Click around on the links between "for desktop", "for andoid", "os"

Eventually the 'pin to bottom' feature seems to stop working.

Comment 8

[Brian Grinstead [:bgrins]]

Actually, I think I was just able to reproduce on this URL (without Firebug) just by reloading this page: https://air.mozilla.org/new/

Comment 9

[Brian Grinstead [:bgrins]]

A positive note is that it *seems* this is resolved by the patch in Bug 1143224 (which is already in the review process).  I'm not positive though because the issue seems pretty intermittent for me

Comment 10

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to Brian Grinstead [:bgrins] from comment #6)
 
> OK thanks, and do you have e10s enabled?

I do, but just tried with e10s disabled, and it still happens (which you have already seemed to discover); thanks!

Comment 11

[Jan Honza Odvarko [:Honza] (always need-info? me)]

> Actually, I think I was just able to reproduce on this URL (without Firebug) just by reloading
> this page: https://air.mozilla.org/new/

Yep looks like a platform problem.

Btw. I tried to repro the issue using:
https://www.mozilla.org/en-US/firefox/desktop/
https://air.mozilla.org/new/

...but I couldn't see it on my machine. The only case
where the scroll bar didn't stay at the bottom was 
when I changed height of the Toolbox (can be during page
load or see my STR).

My STR:
1. Open the Toolbox, select the Network panel
2. Load https://getfirebug.com/tests/head/net/601/issue601.html
3. Click the button on the page till the vert scroll bar appears
4. Make the Toolbox smaller
5. Click the button again
6. The scrollbar doesn't stay at the bottom.

It feels ok to me, but I am mentioning it here anyway to make sure we don't miss anything.

Honza