[webkit-dev] Code cleaning: LEGACY_VIEWPORT_ADAPTION

Benjamin Poulain benjamin at webkit.org
Wed Oct 30 11:11:01 PDT 2013

On 10/30/13, 7:44 AM, Hugo Lima wrote:
> On Tue, Oct 29, 2013 at 9:00 PM, Benjamin Poulain <benjamin at webkit.org> wrote:
>> I plan to remove the code guarded by LEGACY_VIEWPORT_ADAPTION and the flag
>> itself.
> I was reading the original bug report[1] to find a list of websites
> targeting mobile devices that don't render well if this feature is
> disabled, the original list includes:
> m.yahoo.com
> m.google.com
> m.facebook.com
> All this if you do not use some apple-like user agent, I did test them
> again today to check the current status and just m.google.com is still
> using those legacy DTD causing WebKit to render the page into a 980px
> canvas where it was designed to be rendered into a 320px canvas. There
> may be other (old) sites not rendering well but at least at the time
> of the bug report this small list with very popular websites was
> enough to add this feature to a product (N9 phone) then to WebCore.
> I also found that besides Blackberry, Chromium turned on this flag[2]
> last year, but I didn't check if it still enabled on blink.

It is okay to adapt the viewport for the mobile doctypes. WebKit on iOS
also does that for the reasons you mentioned.

The problem here is the code is not correct.

> Support legacy stuff is a pain and just inject undesirable code in the
> codebase, but I would like to know if there are other options rather
> than just removing the feature and let few, but some important,
> website not working?

If Nix really relies on that code, I will leave it in for now.

When the relevant iOS bits and pieces will be upstream, it will be
easier to implement viewport adaptation and I'll remove


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