1336334 - [viewport] initial-scale=2.0 clamp to 980px on a 360px screen

Status: RESOLVED DUPLICATE of bug 1494422

(Core :: Panning and Zooming, defect, P3)

Description

[Karl Dubost💡 :karlcow]

(change the product/component adequately if I missed something)

This issue is part of a couple of tests, I'm doing comparing Firefox Android and Chrome Android for layout differences wrt viewport values.
The tests are available at http://la-grange.net/2016/12/01/viewport/

Test 0005 - <name="viewport" content="initial-scale=2.0">
http://la-grange.net/2016/12/01/viewport/viewport-test-0005.html

Screenshots are not necessary useful here, but the values are interesting.


Firefox
    1: window.devicePixelRatio
    980 px: document.documentElement.clientWidth
    879 px: document.documentElement.clientHeight
    964 px: document.body.clientWidth
    1309 px: document.body.clientHeight
    360 px: window.screen.width
    592 px: window.screen.height
    360 px: window.innerWidth
    592 px: window.innerHeight


Chrome
    3: window.devicePixelRatio
    180 px: document.documentElement.clientWidth
    255 px: document.documentElement.clientHeight
    164 px: document.body.clientWidth
    2076 px: document.body.clientHeight
    360 px: window.screen.width
    640 px: window.screen.height
    360 px: window.innerWidth
    640 px: window.innerHeight

Comment 1

[Karl Dubost💡 :karlcow]

when initial-scale is different from 0 be for 0.5 ( Bug #1336330 ) or 2.0 (here), Firefox seems to clamp the documentElement.clientWidth to 980px.

Comment 2

[Karl Dubost💡 :karlcow]

The values are strange, I'm hesitating opening a separate bug for this test with an extreme small value.
http://la-grange.net/2016/12/01/viewport/viewport-test-0006.html

* Firefox
    3600px: document.documentElement.clientWidth

* Chrome
    1440px: document.documentElement.clientWidth

This time Chrome seems to clamp.

Comment 3

[Hiroyuki Ikezoe (:hiro)]

This seems also to be relevant with 'extend-to-zoom'.

Comment 4

[Hiroyuki Ikezoe (:hiro)]

Now I am convinced this case will be fixed by 1494422.