297036 - Extra blank line in rendered textarea

Status: RESOLVED DUPLICATE of bug 320883

(Core :: Layout: Form Controls, defect)

Description

[servalan]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511 Firefox/1.0.4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511 Firefox/1.0.4

Distributed Proofreaders (http://www.pgdp.net) helps produce etexts for Project
Gutenberg. To assist with the proofreading process we have developed a web based
javascript application (Proofreading Interface) - running happily for a few
years now.

We are starting to see complaints from our Firefox & Mozilla users of blank
lines appearing intermittently (triggers unknown) in the rendered textarea of
the Proofreading Interface. This may or may not be accompanied with a
corresponding blank line in 'View Source' output.

You can see the problem demonstrated in this screenshot:
http://www.pgdp.org/~pourlean/blank_line.jpg

The texarea is in a frame which has an 'onload' javascript action that calls a
function whose definition is associated with 'top'. These factors appear to be
implicated, but the behaviour is not quite consistent enough to tell.

Reloading the frame, or opening frame in new window, make the extra blank line
go away, as does saving the frame to a file and opening that.

The problem appears to be somewhat deterministic: repeated fetches of same page
show same blank line. However moving the page content to another server and
fetching from there causes the blank line to not appear.

As far as we know, it's always an inserted blank line (i.e. one line-end changed
to two), rather than simply a randomly-inserted line-end.

Logins for mozilla devs available via email to bug submitter. Additional info in
this post:
http://forums.mozillazine.org/viewtopic.php?p=1524029#1524029

Reproducible: Sometimes

Steps to Reproduce:
1. For some Distributed Proofreaders users, for some users...
2. Load a page into the Proofreading Interface

Actual Results:  
A blank line appears in the text area. The problem appears to be somewhat
deterministic: repeated fetches of same page show same blank line.

Expected Results:  
The text should have been rendered as it was downloaded from the server, without
the extra blank line.

Comment 1

[servalan]

This bug has appeared using the following browsers:

Mozilla 1.7.3 under Windows XP
Firefox 1.0 Win XP Pro Service Pack 1
Firefox 1.0.4 Windows XP SP2
Firefox 1.0.4 Windows XP Pro. 
Firefox 1.0.4 XP Home SP1
Firefox 1.0.3 Linux

We have no reports for any other browsers (yet) - the majority of our users use
IE, but many are switching to FF, so we are seeing an increase in the reporting
of this problem.

Comment 2

[William Bumgarner [:zsinj]]

Has this been tested with any nightly (1.0+) builds?
http://www.mozilla.org/developer

Comment 3

[Christian Reis]

Is this bug a dupe of bug 241263?

Comment 4

[servalan]

Yes, I did test the case I can reproduce with a nightly build around the 8th
June. I could not reproduce the problem.

Unfortunately the nightly build I used fails to render .pngs reliably so I can't
do more extensive testing.

I can try again with a more recent nightly build if needed.

(from my mozilla forum post)
I also made a recommendation to our users that they move back to IE if they have
switched for proofreading until Firefox 1.1 is released. The users who cannot
switch will just need to be vigilant & use 'Reload Frame' as a workaround.

I just hope the nature of the fix doesn't change between the nightly build I
tested on & the 1.1 release, which is always a danger when a bug is not fully
understood.

Comment 5

[Christian Reis]

I'm not sure this has actually been fixed or if you just haven't been able to
reproduce the problem. Can you try with a more recent nightly?

Comment 6

[William Bumgarner [:zsinj]]

This obviously isn't fixed in FF1.1 considering we're still working off of
1.0.4+ builds. If you define Deer Park Alpha 1 (DPa1) as "FF 1.1" then you are
mistaken. The nightly builds we put out are the most cutting edge version you
can get without compiling a version yourself. All bug fixes get put into the
cycle of being incorporated into the nightly builds whihc eventually work up to
public releases (such as FF1.1).

If you still see the problem, then there IS still this problem (be it in the
browser, your server, or what have you).

Looking back at the original comment, the quote, "However moving the page
content to another server and fetching from there causes the blank line to not
appear," leads me to believe that the problem isn't with FF. Are you confident
that this extra line is only produced in FireFox and only when the content is on
that server?

Sorry if I appear demanding, which is not intended, I'm just persistant.

One more comment: Always use the most recent nightly build. We update daily and
usually encourage bug reporters to update if their version is more than two
weeks old.

Comment 7

[servalan]

> Are you confident that this extra line is only produced in FireFox 
> and only when the content is on that server?

The problem is exceedingly difficult to reproduce. The Mozilla devs who showed
up in our jabber conference room were also flummoxed.

I can say quite confidently that it is a problem which only appears with Mozilla
based browsers. I have used the javascript application on over 25000 pages in IE
without a problem. In 50 pages tried with FF 1.0.4 I had extra blank lines show
up 2 times. 

The server is not sending the blank line, it is rendered in the browser. Hence I
believe it is a FF problem.

Some help building a test case would be appreciated. I will try another nightly
build with the page I can reproduce the problem on and see what happens. As I
mentioned previously, the nightly build I tried in June didn't render pngs
correctly, so it was useless for extended testing or for normal use.

I hope all that makes sense - I am [e-mail] if you wish to discuss
this problem in real time via jabber, http://www.jabber.org

Comment 8

[Boris Zbarsky [:bzbarsky]]

So..  I hate to ask this, but is this still an issue in current trunk builds?

Comment 9

[servalan]

No longer an issue as far as I can determine - I believe it was tracked down to be a case of:
https://bugzilla.mozilla.org/show_bug.cgi?id=320883
Please close this bug as fixed as per the above bug. I'll reopen that bug should we see it again.

Many thanks!

Comment 10

[Boris Zbarsky [:bzbarsky]]

Ah, great!