[webkit-dev] Adding ENABLE_NAVIGATOR_BUILDTYPE to WebCore

[Adam Barth]

On Thu, Jun 7, 2012 at 12:53 PM, Annie Sullivan <sullivan at chromium.org> wrote:
> On Thu, Jun 7, 2012 at 3:43 PM, Dean Jackson <dino at apple.com> wrote:
>> On 07/06/2012, at 12:05 PM, Annie Sullivan <sullivan at chromium.org> wrote:
>>> In many browsers in the past, it's been
>>> pretty easy to determine from "a" and "b" characters in the user agent
>>> of many browsers which builds are "alpha" and "beta", and I haven't
>>> heard of bugs caused specifically by checking for build type there.
>>
>> So why not just do that then?
>
> While it's nice that web developers don't seem to be using the build
> type info in the user agent string in their code, user agent parsing
> code is still very brittle. Some browsers, like Firefox, have had
> buildtype characters in the user agent string for many years, so
> parsing code can handle things like "Firefox/14.0a2". But Chrome
> hasn't ever changed its version format, so we're worried about
> breaking user agent parsers.

Even beyond that, putting the buildType in the User-Agent seems
strictly worse that exposing it as a separate property to JavaScript.

Adam