872650 - Regression: Buecherhallen.de rendered far too large on first-load

Status: RESOLVED WORKSFORME

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

Description

[Aaron Train [:aaronmt]]

Attachment: Firefox 20 | Firefox 21 (Screenshot)

Initially reported via Marco Zehe through email.

Load https://www.buecherhallen.de/Mobile in Firefox 20, compare it to Firefox 21 where everything on initial load is zoomed in.

See screenshot (Fx20|Fx21).

--
LG Nexus 4 (Android 4.2.2)
Firefox 20/21

Comment 1

[Mark Finkle (:mfinkle) (use needinfo?)]

We'll see if we can get a fix that we can uplift

Comment 2

[Kartikaya Gupta (email:[e-mail])]

I bisected this on nightlies and it appears to be a regression from the range http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=36525224b14e&tochange=161a347bda5b. Most likely bug 833003, confirming now with a local build with that backed out.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

Yeah, this is a regression from bug 833003.

Comment 4

[Tetsuharu OHZEKI [:tetsuharu] (UTC+9)]

In this case, this page has `<meta name="viewport" content="user-scalable=no">`. We should treat as the following from spec: http://dev.w3.org/csswg/css-device-adapt/#viewport-meta, right? (I don't know well about how to read the spec.):
```
@viewport {
  width: extend-to-zoom;/* this will be calculated as `auto` */
  height: extend-to-zoom;/* this will be calculated as `auto` */
  user-zoom: fixed
}
```

Comment 5

[Kevin Brosnan [Ex-Mozilla]]

Needinfo from mbrubeck about comment 4

Comment 6

[Kartikaya Gupta (email:[e-mail])]

I'm not really looking into this right now; re-assigning.

Comment 7

[Tetsuharu OHZEKI [:tetsuharu] (UTC+9)]

I cannot start to work about this without any spec information...

Comment 8

[Matt Brubeck (:mbrubeck)]

I think the interpretation of the spec in comment 4 is correct.  Also, according to the CSS Device Adaptation spec the zoom, min-zoom, and max-zoom properties will be 'auto'.

The spec does not actually define how the UA should initially zoom the page initally when 'zoom' is set to 'auto' and so the behavior on this page is undefined.  However, the spec does have a non-normative suggestion that would make this page render as intended if we implemented it correctly:
http://www.w3.org/TR/2011/WD-css-device-adapt-20110915/#handling-auto-zoom

Comment 9

[Tetsuharu OHZEKI [:tetsuharu] (UTC+9)]

I confirm this is not reproducible if we set `browser.ui.zoom.force-user-scalable`.
SO we should handle this part.

Comment 10

[Tetsuharu OHZEKI [:tetsuharu] (UTC+9)]

* `browser.ui.zoom.force-user-scalable` only effects `metadata.allowZoom`, `metadata.minZoom`, or `metadata.maxZoom`: http://hg.mozilla.org/mozilla-central/file/57d160eda301/mobile/android/chrome/content/browser.js#l3807.
  * `maxZoom` & `minZoom` are set `NaN`.
* This bug is looks like the bug of zooming.
* if the document has `<meta name="viewport" content="user-scalable=no">`.
  * `metadata.defaultZoom` would be `NaN` by `ViewportHandler.getViewportMetadata()
  * `metadata.maxZoom` would be `NaN` by `ViewportHandler.getViewportMetadata()
  * `metadata.minZoom` would be `NaN` by `ViewportHandler.getViewportMetadata()
    * `ViewportMetadata` constructor don't assert & modify parameter's values. 

From above, `metadata.allowZoom` relate to this bug.

* It is referenced from http://hg.mozilla.org/mozilla-central/file/57d160eda301/mobile/android/chrome/content/browser.js#l3983.
* If `browser.ui.zoom.force-user-scalable`  is true, this method returns `zoom`. Because, `metadata.defaultZoom` would be `NaN`.

So I think we should need to fix the constructor of `ViewportMetadata`, `Tab.sendViewportMetadata()`, or `Tab.clampZoom()`.

Comment 11

[Tetsuharu OHZEKI [:tetsuharu] (UTC+9)]

With using debugger, I check the above codes. But local variables & the value of `sendViewportMetadata` are no different whether `browser.ui.zoom.force-user-scalable` is true or false.

Now, I research http://hg.mozilla.org/mozilla-central/file/57d160eda301/mobile/android/base/gfx/JavaPanZoomController.java#l1050

Comment 12

[Brad Lassey [:blassey] (use needinfo?)]

filter on [mass-p5]

Comment 13

[Kartikaya Gupta (email:[e-mail])]

This works fine now. The site may also have been redesigned in the interim, but when I load this page in Nightly 52 it shows up at the right zoom level.