1491213 - user's zoom operation will changes the reference value of initial-scale

Status: RESOLVED DUPLICATE of bug 1498729

(Firefox for Android Graveyard :: General, defect, P5)

Description

[blackgloryzh]

Attachment: actual.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0
Build ID: 20180830143136

Steps to reproduce:

1. Open any website that does not have a viewport meta tag like https://bugzilla.mozilla.org
2. Zoom in screen by two fingers
3. Open desktop WebIDE and connect the tab opened on Firefox for Android
4. execute the script:
function createViewportMetaElement(viewport) {
  const meta = document.createElement('meta')
  meta.name = 'viewport'
  meta.content = Object.entries(viewport)
    .filter(([, value]) => !!value)
    .map(([key, value]) => `${ key }=${ value }`)
    .join(', ')
  return meta
}

document.head.appendChild(createViewportMetaElement({
  'width': 'device-width'
, 'initial-scale': '1'
}))

Tested browsers can reproduce this issue:
Firefox for Android 62.0.1
Firefox for Android Beta 63.0b5
Firefox for Android Nightly 64.0a1(2018-09-13)


Actual results:

You will see the page zoom in, but it is obviously too big.


Expected results:

Just ignore step 2.

I think the reference value of the initial-scale should not be changed by the user's zoom operation. It is working as expected in Chromium.

Comment 1

[Hiroyuki Ikezoe (:hiro)]

I am not sure yet what's going on there, but with 'initial-scale: 0.5' chrome is also affected by the change.

Comment 2

[Kevin Brosnan [Ex-Mozilla]]

Boton you have been looking into zoom/viewport issues is this a dupe of something known?

Comment 3

[Botond Ballo [:botond]]

(In reply to blackgloryzh from comment #0)

1. Open any website that does not have a viewport meta tag like
   https://bugzilla.mozilla.org

bugzilla.mozilla.org does have a meta viewport tag. It's:

<meta name="viewport" content="width=1024">

By adding a second meta viewport tag, you're probably running into bug 1498729.

Comment 4

[Hiroyuki Ikezoe (:hiro)]

Confirmed that bug 1498729 fixed this.