Hi,
we add an extra-string to user agents in our webpagetests. For Firefox-tests we used to add the following to ./templates/Firefox/prefs.js on agents:
user_pref(“general.useragent.extra.webpagetest”, “our-key-to-identify-monitoring”);
Since a while that doesn’t work anymore. I can see PTST in user agent, but not our key added via user_pref 
Any ideas? Anything changed in setting/adding PTST-String to user agent in the recent past?
Maybe firefox-version dependent? I tested with versions 26 to 29 and the user agent isn’t added in any of these. The ff-pref general.useragent.extra.[product/version] isn’t marked as deprecated ore something here: About:config entries - MozillaZine Knowledge Base
Strange, anyway …
Regards, Nils
Any chance it’s SSL content? Just wondering if I fixed a bug where we were not correctly modifying headers and accidentally broke your use case. If you check the “keep original UA string” option does your pref start working again?
No, than PTST disappears, but our identifier isn’t added, too.
If you add that to a normal firefox profile and check the UA manually do you see it? I shouldn’t be touching the headers anymore if you flipped the bit so it looks like firefox itself isn’t getting the pref.
you’re right
I’ll have a look why the ff-pref general.useragent.extra.[product/version] doesn’t work in ff 29 on our agents, anymore. I’ll report here if I get an idea.
No, unfortunately not. The general.useragent.extra.* preference doesn’t seem to work anymore in actual ff-versions. We take general.useragent.override instead which isn’t the same cause it doesn’t sustain the original useragent, but it works.