455473 - Overflowing textarea takes a long time to lay out

Status: RESOLVED WORKSFORME

(Core :: Layout: Form Controls, defect)

Description

[Geoff Lankow (:darktrojan)]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1a2) Gecko/20080829082037 Shiretoko/3.1a2
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1a2) Gecko/20080829082037 Shiretoko/3.1a2

A small textarea with a large amount of content takes an excessive time to lay out the content.

Reproducible: Always

Steps to Reproduce:
1. create a page with the code <textarea style="width: 5px; height: 100px">... lots of text ... </textarea>
2. load in browser
3. wait
Actual Results:  
Page gets drawn, then processor use goes to 100% for >20s as text is laid out in the textarea

Expected Results:  
Page is drawn and no excessive lag is experienced

It seems the browser is laying out all of the extra text in the textarea, even the overflowing text.

Works fine in IE/Opera/Safari

Comment 1

[Geoff Lankow (:darktrojan)]

I've discovered that I can't reproduce this bug in Firefox 3.0

Comment 2

[Geoff Lankow (:darktrojan)]

Attachment: Test case

Comment 3

[Boris Zbarsky [:bzbarsky]]

Can't reproduce, but I have current trunk, and I'm on Mac.  Martijn, do you see this?

Geoff, just to make sure, are you seeing this in safe mode too?

Comment 4

[Martijn Wargers (dead)]

Yeah, I'm seeing this a high cpu usage of 1s or so, but not more than that in current trunk build. Older builds don't show this high cpu usage. This regressed when bug 99457 (word-wrap) got fixed.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Ah, yeah. That could do it.  We should figure out why it takes so long on Geoff's setup.

Comment 6

[Martijn Wargers (dead)]

Geoff, what computer do you have? What cpu? How many MHz?

Comment 7

[Geoff Lankow (:darktrojan)]

Yes my computer is on the old side (850MHz PIII), but I've just timed the test case and it took about 45s at 100%. That's more than just an old computer causing it.

Same thing happens in safe mode.

Comment 8

[Geoff Lankow (:darktrojan)]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080916043910 Minefield/3.1b1pre

30s.

Comment 9

[Guilherme Lima]

The testcase page was draw immediately for me.