227683 - combobox (<select> tag/dropdown list) caption/text is shown/displayed partially, while list item is okay

Status: RESOLVED FIXED

(Core :: Layout: Form Controls, defect)

Description

[Silviu Julean]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.5) Gecko/20031007 Firebird/0.7
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.5) Gecko/20031007 Firebird/0.7

While browsing the URL (and all comics in the same chapter as well, haven't
tried others) i noticed that in some cases the caption of the combo box below
the comic (the one which should say "Bun-bun's Theatre of Horrors") is not
completely shown  - i only see a random prefix of it (i even got just "Bun-bu"
at one time). Expanding the combo shows the right <option selected> item,
including its full name. Selecting it again doesn't change the caption, but
selecting another item and selecting the default one back solves the problem.

Reproducible: Sometimes

Steps to Reproduce:
1. Open the site in the URL field in Firebird
2. Play around with the <previous comic> and <next comic> buttons until the
combo only displays a prefix of the right text
3. If you don't get the effect, try a smaller resolution, or a lower bandwidth

Actual Results:  
Sometimes, the text in the combo box only displayed a prefix of its actual
title. The length of that prefix (in characters) was different every time.

Expected Results:  
Mozilla (and Firebird) should have displayed the complete title of the selected
option.

I have tested this with Firebird 0.7 and Mozilla 1.4 (old, I know, but I've
spent a lot of time checking for similar bugs.)
I was using 800x600 at the time, so the combo wasn't in the "view port" when the
page started to load.
I have a TV Cable connection to the Internet. I don't think this is only
happening on slow connections.

Comment 1

[Silviu Julean]

Attachment: Firebird 0.7 screenshot

Mr. Abrams, sorry for attaching a couple of screenshots.

Comment 2

[Silviu Julean]

Changed version to 1.4 branch - I have seen this on Mozilla 1.4 and Firebird
0.7. If other branches are tested, please feel free to update.

Comment 3

[Andreas Kunz]

Confirming, I also see this occasionally, e.g. on the bugzilla bug query form
(it says "Web Se" where it should say "Web Services").
Wanted to file this myself and found this bug, but no other dups.

Last seen today with Mozilla 1.7 (Windows XP), so there is no reason to believe
this is only on a certain branch -> "Trunk".
Unfortunately this is not reproducible by any set of steps. It happens here with
high speed connection and always the same resolution.

Adjusting summary to make this more "findable"...

Comment 4

[Silviu Julean]

Still happening in Firefox 0.9.1 on Windows 2000 SP4, 1024x768. Didn't see it in
any other site, though. Still not reproducible.

Comment 5

[Andreas Kunz]

I think I just saw how this bug is caused:
While loading a page with a combobox
(http://www.steves-digicams.com/hardware_reviews.html, but I don't believe the
page matters), there was a stage during loading where parts of the page
(including the combobox) were already shown, but the layout was not final,
probably because not all page content was loaded yet.
During this stage the combobox's width was smaller than usual and not all of its
text was displayed. When loading finally was finished, the combobox was wider,
but still only that part of text that was visible before was there.

(One additional thought: combobox options _might_ be generated by javascript and
this might not be finished when the text in the box was laid out. This could be
an alternative cause to slow loading of the page html code. Probably not, but
I'd want to mention it.)

Comment 6

[Christian :Biesinger (don't email me, ping me on IRC)]

*** Bug 270482 has been marked as a duplicate of this bug. ***

Comment 7

[Boris Zbarsky [:bzbarsky]]

Can someone create a testcase from comment 5 that reliably reproduces this bug?

Comment 8

[Martijn Wargers (dead)]

Sorry, I can't reproduce the bug, and I've tried a lot to reproduce. I only
found this:
http://martijn.heelveel.info/test/mozilla/select/show_bug.html (warning! can
slow down your browser)
But that could be something totally different. 

Comment 9

[Erik Fabert]

*** Bug 280076 has been marked as a duplicate of this bug. ***

Comment 10

[Erik Fabert]

The following ASP.NET page reproduces the bug reliably on every shift-reload. It
should be easy enough to port to Perl, PHP, etc.:

<%@ Page Language = "JavaScript" Buffer = "false" %>

<select>
<option selected>This should be

<script runat="server">
// Sleep 5 seconds.
var t = System.Threading.Thread.Sleep(5000);
</script>

a complete sentence.</option>
<option>Another option</option>
</select>

Comment 11

[Martijn Wargers (dead)]

Thanks Erik!
Here is a php example of the bug:
http://martijn.heelveel.info/test/mozilla/option_sleep.php
Remember, the bug only happens on first load/shift->reload

Comment 12

[Boris Zbarsky [:bzbarsky]]

So the problem here is that when the parser calls AppendData() on the textnode
inside the <option> the <option> itself doesn't know that this happened (and
hence can't make the nsHTMLOptionElement::NotifyTextChanged call it wants to
make here.

IRC conversation with sicking:

<sicking> bz: what we should simply do is to add a function like
+nsIContent::ChildDataChanged(nsIContent* aChild)
<sicking> bz: and have textnodes call that on their parent in SetData

Comment 13

[Eric]

i have this same problem with my own site
It shows: "Alle", but the text is supposed to be "Alle catagorieën", and it does
show it right in the source. Its just plain html generated by a java servlet,
and it happens at random. Sometimes its good, sometimes it isnt

the source:
<select class="inputitem" name="catagorie">
<option value="" selected="selected">Alle catagoriëen</option>
<option value="101">Techniek</option>
<option value="102">Thriller</option>
<option value="103">Spanning</option>
<option value="104">Avontuur</option>
<option value="105">Historie</option>
<option value="106">Roman</option>
<option value="107">Reizen</option>
<option value="108">Jeugd</option>
<option value="109">Hobby</option>
<option value="110">Science Fiction</option>
<option value="111">Porno</option>
</select>

Nothing special i guess
It happens alot when i select the "Alle catagorieen" item, and then press the
Opzoeken button.
Screenshots:
http://grit.programmin.net/site1.png
http://grit.programmin.net/site2.png

Comment 14

[Eric]

forgot to mention:
Firefox 1.0 English
Windows XP SP2
1280x1024 screen resolution
the site uses xhtml transitional stuff and was successfully validated by the w3
validator

Comment 15

[Boris Zbarsky [:bzbarsky]]

Eric, we know why this happens, and have a minimal testcase.  No need to comment
on this bug unless you're proposing a specific fix.

Comment 16

[Martijn Wargers (dead)]

The url of the testcase from comment 11 has become:
http://wargers.org/test/mozilla/option_sleep.php

Comment 17

[Martijn Wargers (dead)]

This is WFM with 2005-10-20 trunk build, using:
http://wargers.org/test/mozilla/option_sleep.php

Comment 18

[Boris Zbarsky [:bzbarsky]]

Yeah, this was fixed by bug 297389...