When custom user agent string field is empty, we should use the User Agent string of the same browser as client uses

[BooBerry]

Edit by ameshkov:
We should change the default behavior of "Hide User Agent" feature. When custom user agent string field is empty, we should use the User Agent string of the same browser as client uses.

If user uses IE - use IE user agent, if FF - use FF, etc.

Original text:
http://forum.adguard.com/showthread.php?9324-Trouble-in-Gmail-AG-v-6-0-189-984

Steps to reproduce:

1. Enable Enhanced Protected Mode (I also enabled the 64-bit processes for Enhanced Protected Mode option) under IE's settings.
2. Enable Stealth Mode and enable the Hide your User Agent feature (without setting a custom user agent).
3. Open IE and go to Gmail with a signed in account (and make sure you have email in the inbox).
4. Open an email, press the reply button below and try to type into the box. It doesn't work.

If you change the user agent to a custom one (I used an IE11 user agent in this case) the issue resolves itself.

[ameshkov]

@BooBerry I've updated the issue description, please check it out

[BooBerry]

I agree, but in the case of IE, Edge and Safari it should also use the OS they're available on (Windows for IE/Edge and Mac for Safari in this case). I'm thinking any other OS would also break stuff when using those browsers.

[ameshkov]

We can simply strip everything "extra" from the user agent

[BooBerry]

Here's another example where using the Linux user agent causes issues on a Windows machine: http://forum.adguard.com/showthread.php?9493-Win-7-64-bit-identifying-as-Linux

The user agent should also match the OS Adguard is running on to prevent issues like this.

We can simply strip everything "extra" from the user agent

Yes, but match OS, browser and browser version to the native browser/OS. The last is important because using an older browser version in the user agent might also break sites, especially email. Just strip everything else. :)

[ameshkov]

Yes, I agree, OS and version is also important.

[marzametal]

If the only thing that changes here is the empty User Agent behaviour, then all is well. Please don't prevent Host OS from acting as an alternative OS.

I like disguising my Windows 7 OS as Linux via Stealth Mode/User Agent String. I mean seriously, that's the whole point of Stealth isn't it? Preventing this is not a solution, it is a restriction. The drop-down list containing User Agents seems to me to be an optimal solution. It might also benefit those who use User Agent addons in browsers to go with one addon less.

[ameshkov]

Yep, the only change is when "user agent" field is empty. You always can set any user agent manually.

[suhan3z]

Fixed