1047370 - when i disable javascript in about:config javascript on opened pages still run

Status: RESOLVED DUPLICATE of bug 998456

(Firefox :: Untriaged, defect)

Description

[Sergei Lastochkin]

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release)
Build ID: 20140605174243

Steps to reproduce:

1. I go to page of my website. Let's call this tab TabA
2. I open new tab. In that tab I go to about:config. Let's call it TabB. In TabB I find option "javascript.enabled". Then I set it to "false".


Actual results:

JavaScript in TabA is still running. It will stop only when I refresh this tab.


Expected results:

JavaScript in TabA should have died or paused.
In older versions of firefox it paused but in Firefox 30.0 behavior has changed. In older versions It would even "wake up" if you change "javascript.enabled" to "true".

Rationale why old behavior is better that new:
1. Old behavior guaranteed that all JS (potentially harmful) in opened tabs can be killed or suspended instantly on your suspicion. (for example when you see some strange ajax requests on your site in firebug while in public or admin page - this is critical situation which must be frozen and explored carefully. Оr when page is filled with unwanted stick-to-your-face-banners. Or when you run into processor-intesive page with features you don't want)
2. It was so for a long time and became intuitive behavior.
3. Useful feature during site development for testing number of Javascript widgets.
4. While taking away old feature, no new alternative was given.
5. New behavior situation could be easily replicated by old one if needed.
6. Casual users wouldn't go to "about:config". They don't get pros or cons from behavior change.