Settings window freezes Firefox for a long time / sometimes crashes it

[scroom]

As described above. I'm using https-everywhere 5.0.4 within Firefox 38 on Ubuntu 14.04.

[reedy]

Can you try with a new ff profile to see if that helps?

[reedy]

Also, where did you build of FF 38 for 14.04 come from?

http://packages.ubuntu.com/trusty/firefox and http://packages.ubuntu.com/trusty-updates/firefox only offer 37.0.2

[scroom]

The package came via update:

https://launchpad.net/ubuntu/+source/firefox/38.0+build3-0ubuntu0.14.04.1

I will try to add a new profile and to test if the bug appears there as well.

[scroom]

Tried it with a new clean profile. Firefox didn't crash but produced high CPU-load and a lot of memory was in use. Then I tried my old profile again and realized that Firefox there as well wasn't crashing but in a freeze for more then a minute. The CPU load lasted even longer on 100% and up to 900MiB memory were in use. After more then a minute the settings window appeared but in the list there were no visible entries. I clicked "OK" and reopened the settings windows. This time the window appeared directly and the list were visible.
After closing and reopening the Firefox window again the first attempt to open the settings window of https-everywhere produced high load and made Firefox freeze and on the second attempt the window appeared directly.

[reedy]

See also #1775

[pde]

I can reproduce this in FF 39 / HTTPSE 5.0.5, but may not have time to work on it till late in the week. May be able to provide some data to others, though...

[jsha]

This happens because the settings window includes a list of all rulesets packages with HTTPS Everywhere. To show that list, HTTPS Everywhere loads all rulesets into memory at once (normally it loads rulesets on an as-needed basis). That's a lot of memory, and it's also a lot of CPU time to parse all that XML.

My preferred fix for this is to simply remove the settings window. It shows all the rulesets at once, which is somewhat meaningless when we have 15k+ rulesets. That's also redundant with the HTTPS Everywhere Atlas. The one setting from that window that we probably want to keep is "Reset to Defaults," which should be moved into the primary window anyhow. The settings window is accessible through "Enable / Disable Rules" in the HTTPS Everywhere icon menu, and by clicking "Settings" from the Firefox Extensions page, so we'd have to pull it out in both places.

The alternative is to modify the settings page so that it doesn't show any rulesets when it first opens, and then only loads rulesets in response to a query. This is more complicated to write, and there are probably still some queries that will load so many rulesets they will freeze the browser.

(updated with more detail crossposted from the mailing list)