1440652 - Text inconsistency inside the Simplify Page between Ubuntu versions

Status: NEW

(Toolkit :: Printing, enhancement, P3)

Description

[Anca Soncutean, Desktop QA]

[Affected versions]: 
- 60.0a1 (2018-02-22)

[Affected platforms]:
- Ubuntu 16.04 (x86 and x64)
- Ubuntu 14.04 (x86 and x64)

[Steps to reproduce]:
1. Launch Firefox 
2. Go to https://en.wikipedia.org/wiki/Albert_Einstein 
3. Print Preview the page and click on the Simplify Page button
4. Observe the text alignment, in the numbering area 

[Expected result]:
- The text is correctly displayed.

[Actual result]:
1. - The numbers are not properly aligned on Ubuntu 14.04 x86  and Ubuntu 16.04 x64.
Screenshot exemple: Ubuntu 14.04 (x86 vs x64): https://goo.gl/b4ehJY vs https://goo.gl/FuZRbF ).
2. - The heading "Further reading" is slightly positioned on the the left side on Ubuntu 14.04 x64 and Ubuntu 16.04 (both on x86 and x64).  
Screenshot exemple: Ubuntu 14.04 (x86 vs x64) https://goo.gl/jhWXzd vs https://goo.gl/VUBC1u).

[Regression range]:
- Not a regression, I was able to reproduce this issue on Nightly from 2018-01-03 as well (where the feature was first introduced on Linux).

Comment 1

[Jonathan Kew [:jfkthame]]

I'm not sure there is a Firefox bug here. In the screenshots (both examples 1 and 2), the two systems are using entirely different fonts, which may well be a difference in system configurations rather than a Firefox issue.

In particular, in (1), the first image shows a font that has "oldstyle" numerals, while the second one has "lining" numerals. The "oldstyle" numerals are not misaligned, they are designed to be at different heights on the line.

And in both cases, the fonts used are clearly different: this is particularly obvious in the design of some of the italic letters, such as "f", "v" and "y". Metrics difference between the fonts probably explain the apparent positioning difference of the "Further reading" heading. 

So my question is whether this is simply a configuration difference between the systems (different default serif fonts? or the page style requests a specific font-family that is present on one system, but absent on the other?). Or are they truly identical configurations, yet Firefox is resolving fonts differently? That would indeed be a bug.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

ni?ing Anca for comment 1. P3'ing for now.

Comment 3

[Anca Soncutean, Desktop QA]

This issue has a strange behavior, and it seems that it depends more on the testing machine, than on the version involved.

 1. The heading “Further reading” alignment issue:
    - I can't see the issue anymore, or any differences between Ubuntu versions.

 2. The number displaying issue: 
    - Still looks bad on 14.04 (both on x86 and x64). This is the default font for Ubuntu 14.04 https://drive.google.com/open?id=1Rwnsi-ohOOV8RSHAAW9_nvD0K3FpJODy . 
    - It seemed like this issue was no longer reproducible on Ubuntu 16.04 (both on x64 and x32) - tested on two different machines,  but after I’ve tested on a laptop (HP ProBook 470 G3) that has Ubuntu 16.04 x64, I could see, that the numbers were still not properly displayed. I couldn’t figure it out, what could be the cause that determines this Ubuntu 16.04 to behave differently, especially since the default font is the same for all the Ubuntu’s 16.04 machines I’ve tested: https://drive.google.com/open?id=1OruZIzD3CipUAo2Xz2GJoMg-ohHMN-jc . 

It is important to mention that the issue is not visible in Printing Page, only in Simplify Page. 
I am not sure on how I should approach differently these inconsistencies and what needs to be done in order to determine the exact cause of this behaviour.