466541 - Page with many elements styled by CSS is rendered slow since Firefox 3

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Pavel Cvrcek [:JasnaPaka]]

Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1b2pre) Gecko/20081124 Minefield/3.1b2pre

1) Get latest Firefox 3.1 NB.
2) Visit URL http://k8.kreteni.cz/tz/mapa.php?tz=cz&osoba=133
3) Firefox stops response and after some time (>20s) renders map with many items styled by CSS.

Page is rendered immediately in Firefox 2.0.0.18.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

What styles make it slow?

Comment 2

[j.j.]

It's about absolut position of lots of images.
Removing 

 div.tz img, img.p { position:absolute } 

from the stylesheet speeds things up.

Comment 3

[Boris Zbarsky [:bzbarsky]]

I'd rather have things like this dependent so we remember to double-check when the other bug is fixed.  It's not uncommon to need a separate fix for the seeming duplicates after all.  :(

Comment 4

[Boris Zbarsky [:bzbarsky]]

If someone can attach an unminimized locally saved version of the page (save page, complete) that still shows the problem, that would be very much appreciated.

Comment 5

[Pavel Cvrcek [:JasnaPaka]]

Attachment: Locally saved version

Comment 6

[roxleitan]

Mozilla/5.0 (Windows NT 6.0; rv:49.0) Gecko/20100101 Firefox/49.0
Mozilla/5.0 (Windows NT 6.0; rv:46.0) Gecko/20100101 Firefox/46.0

I tested on the latest Firefox release(46.0) and latest Nightly build (49.0) using page from attachment and I can't reproduce the issue.
I will close the bug. If anyone can still reproduce the issue on a current build, fell free to reopen it.