1564021 - Treat viewport meta tag as an empty tag if there is no valid content

Status: RESOLVED FIXED

(Core :: Layout, defect, P3)

Description

[Hiroyuki Ikezoe (:hiro)]

+++ This bug was initially created as a clone of Bug #1556275 +++

The site reported in https://webcompat.com/issues/31296 has <meta name="viewport" content="1200“ /> and the meta viewport is invalid so we should treat it as ViewportType::Empty.

Comment 1

[Hiroyuki Ikezoe (:hiro)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=6152a38835bb596cdfe5189a918ffaa2f2423375

Comment 2

[Hiroyuki Ikezoe (:hiro)]

Attachment: Bug 1564021 - Use the default desktop width (980px) in the case where we have any viewport meta element but no valid content there. r?botond

Depends on D37328

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9b98bc3c506d
Use the default desktop width (980px) in the case where we have any viewport meta element but no valid content there. r=botond

Comment 4

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/9b98bc3c506d

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Is this something which should be considered for backport?

Comment 6

[Hiroyuki Ikezoe (:hiro)]

Comment on attachment 9076658 [details]
Bug 1564021 - Use the default desktop width (980px) in the case where we have any viewport meta element but no valid content there. r?botond

Beta/Release Uplift Approval Request

• User impact if declined: User will see some sites are rendered in an unexpected narrow device width so that font-sizes in the contents might be tremendously bigger than expected or some images gets smaller than expected
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: 1564021 (already uplifted)
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): The change is basically trivial, it shouldn't cause any critical issue.
• String changes made/needed: None

ESR Uplift Approval Request

• If this is not a sec:{high,crit} bug, please state case for ESR consideration: On mobile this is also an important fix which was a fallout from bug 1500314
• User impact if declined: Same as above
• Fix Landed on Version: 70
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Same as above
• String or UUID changes made by this patch: None

Comment 7

[Hiroyuki Ikezoe (:hiro)]

(In reply to Ryan VanderMeulen [:RyanVM] from comment #5)

Is this something which should be considered for backport?

Unfortunately yes. I found https://webcompat.com/issues/34891 which is caused by this, there might be other webcompat issues I am not aware of, and of course there are more sites affected by this in the wild.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9076658 [details]
Bug 1564021 - Use the default desktop width (980px) in the case where we have any viewport meta element but no valid content there. r?botond

Fixes some mobile web compat regressions. Approved for GV69 and Fennec 68.1b3.

Comment 9

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/releases/mozilla-beta/rev/c5a662c74c0b

Comment 10

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/releases/mozilla-esr68/rev/a2e7bc6a287a