Bugzilla

(In reply to t28427 from comment #20)
> Look, I was requesting for comment because as in comment #5, this was way beyond architecture breaking sites. They read the docs and there is a mess on Linux platforms.

That comment was written way before we froze the architecture, so please apologize that this did not get any attention. Ultimately, though, that's the reason why I and all other Mozilla staff push hard for one bug per topic. Everything else becomes a mess here.

(In reply to t28427 from comment #20)
> No, "Desktop" does not break sites.

Please apologize for the snark, but: you saying this just shows that you haven't worked in Web Compatibility. :)

I agree with you in saying that the UA string is a mess. In an ideal world, it would look way different (or it might not even exist). The problem with the UA string, however, is that literally every single time we make even a tiny change to it, sites break. And it really doesn't matter how small the change is. When the Firefox version number rolled from 99 to 100, it broke sites because webdevs used broken RegExps that only ever expected two numbers. A recent change to the Android UA string to include the `Linux` identifier as well (see bug 1860417) to fix a known issue ended up breaking Google (see bug 1895513).

Replacing `X11`  with `Desktop` might look easy, and it might work for the sites you tested it on, but no change to the UA string is ever "easy", without risk, or without breakage. Web Developers use the UA string in very unexpected ways all the time, and I am 100% confident there are multiple sites that use the `X11` identifier as a criteria for Linux Desktop, and I'm 100% confident that things will break if we change that.

(In reply to t28427 from comment #20)
> So, my question is, I can open a bug if this is to be fixed and if it can be looked into. Thanks.

Amazon.com works fine on a Linux desktop with the current Linux UA string, and you haven't provided any other examples of broken sites with the current UA, so at least as far as this bug is concerned, I consider that there's nothing to be fixed.

If you have a case where the current Linux User Agent string is breaking a site, you can report that as a broken site [into the `Web Compatibility :: Site Reports` Bugzilla component](https://bugzilla.mozilla.org/enter_bug.cgi?product=Web%20Compatibility&component=Site%20Reports). We'll look into that and find a way to resolve the issue - usually that is by shipping a UA override to specifically that broken site, because that allows us to limit the scope of breakage. But if we notice enough breakage, we consider a global UA change.

If you want to propose that we globally replace `X11` with `Desktop`, the [`Core :: Networking: HTTP` Bugzilla component](https://bugzilla.mozilla.org/enter_bug.cgi?product=Core&component=Networking%3A%20HTTP) would be the right place to make that proposal. You are always free to make such a proposal, but make sure to include good motivations for this change. "It would make more sense" is not a good reason alone, because as I've outlined, this has the chance of breakage. If you want to argue for making it easier for developers to detect desktop devices, maybe `(Desktop; X11; Linux x86_64; rv:125.0)` would be another possible proposal - that would still match existing `X11` checks, but also include `Desktop`. However, that change also has the risk of breakage, of course.

It could be worth a discussion either way if you feel strongly about this, but I will be honest and just warn you that we might not be super likely to consider a change to the UA string unless we know about existing breakage with the current UA string that might get fixed with a different UA string.

(In reply to t28427 from comment #20)
> Look, I was requesting for comment because as in comment #5, this was way beyond architecture breaking sites. They read the docs and there is a mess on Linux platforms.

That comment was written way before we froze the architecture, so the extra context was missed. Ultimately, though, that's the reason why I and all other Mozilla staff push hard for one bug per topic. Everything else becomes a mess here.

(In reply to t28427 from comment #20)
> No, "Desktop" does not break sites.

Please excuse the snark, but: you saying this just shows that you haven't worked in Web Compatibility. :)

I agree with you in saying that the UA string is a mess. In an ideal world, it would look way different (or it might not even exist). The problem with the UA string, however, is that literally every single time we make even a tiny change to it, sites break. And it really doesn't matter how small the change is. When the Firefox version number rolled from 99 to 100, it broke sites because webdevs used broken RegExps that only ever expected two numbers. A recent change to the Android UA string to include the `Linux` identifier as well (see bug 1860417) to fix a known issue ended up breaking Google (see bug 1895513).

Replacing `X11`  with `Desktop` might look easy, and it might work for the sites you tested it on, but no change to the UA string is ever "easy", without risk, or without breakage. Web Developers use the UA string in very unexpected ways all the time, and I am 100% confident there are multiple sites that use the `X11` identifier as a criteria for Linux Desktop, and I'm 100% confident that things will break if we change that.

(In reply to t28427 from comment #20)
> So, my question is, I can open a bug if this is to be fixed and if it can be looked into. Thanks.

Amazon.com works fine on a Linux desktop with the current Linux UA string, and you haven't provided any other examples of broken sites with the current UA, so at least as far as this bug is concerned, I consider that there's nothing to be fixed.

If you have a case where the current Linux User Agent string is breaking a site, you can report that as a broken site [into the `Web Compatibility :: Site Reports` Bugzilla component](https://bugzilla.mozilla.org/enter_bug.cgi?product=Web%20Compatibility&component=Site%20Reports). We'll look into that and find a way to resolve the issue - usually that is by shipping a UA override to specifically that broken site, because that allows us to limit the scope of breakage. But if we notice enough breakage, we consider a global UA change.

If you want to propose that we globally replace `X11` with `Desktop`, the [`Core :: Networking: HTTP` Bugzilla component](https://bugzilla.mozilla.org/enter_bug.cgi?product=Core&component=Networking%3A%20HTTP) would be the right place to make that proposal. You are always free to make such a proposal, but make sure to include good motivations for this change. "It would make more sense" is not a good reason alone, because as I've outlined, this has the chance of breakage. If you want to argue for making it easier for developers to detect desktop devices, maybe `(Desktop; X11; Linux x86_64; rv:125.0)` would be another possible proposal - that would still match existing `X11` checks, but also include `Desktop`. However, that change also has the risk of breakage, of course.

It could be worth a discussion either way if you feel strongly about this, but I will be honest and just warn you that we might not be super likely to consider a change to the UA string unless we know about existing breakage with the current UA string that might get fixed with a different UA string.