1378367 - <select> fields with 10000 <option>s take very long to load on windows when "browser.tabs.remote.autostart.2" is true.

Status: RESOLVED DUPLICATE of bug 1118086

(Core :: Layout: Form Controls, defect)

Description

[roman.zimbelmann]

Attachment: a test file to reproduce it

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID: 20161212000000

Steps to reproduce:

1. start firefox 54.0 on windows (tested on win10 and win7) with a fresh profile
2. close and start firefox again. (it does not occur on the very first run)
3. open test.html, which just contains a <select> with 10000 <option>s
4. click on the select field


Actual results:

It takes several seconds before the options show up and you can select one. When clicking on one, it takes a long time again. (oddly, not when pressing "Enter")


Expected results:

The options should show up instantly.

To fix this, I found out that you can change the option "browser.tabs.remote.autostart.2" to false. Possibly "browser.tabs.remote.autostart" needs to be set to false as well.