1406495 - Firefox on Linux renders MathML equations with too much vertical space

Status: RESOLVED DUPLICATE of bug 1208776

(Core :: MathML, defect, P5)

Description

[Wirawan Purwanto]

Attachment: test1.Tutorial-sandbox.htm

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20170811091919

Steps to reproduce:

Open a HTML file containing mathml with vertically stacked letters (See example)


Actual results:

On recent 64-bit Firefox on Linux, I noticed the MathML was rendered with too much vertical space. Please see an attached example (test1.Tutorial-sandbox.htm). The result of rendering was the following:


* test1-img.ffx-ESR52-Linux-x86_64.wirawan2.png
On a debian8 64-bit box, using ESR firefox provided by Debian (Jessie). Math font style looks like "Computer Modern" font, and the vertical spacing was quite wild.

* test1-img.ffx-57.0b6-linux-x86_64.wirawan2.png
On a debian8 64-bit box, using beta version 57 (Firefox Developer Edition). Math font style looks like "Computer Modern" font, and the vertical spacing was quite wild.

* test1-img.ffx-ESR52-Linux-x86_64.turing1.png
On a RHEL 6.9 server, running Firefox 52 ESR (provided by RHEL official repo). Math font style looks like Liberation Sans (or similar), and the vertical spacing looks alright.

* test1-img.ffx-ESR52-Linux-x86_64.terry.png
On an Ubuntu16 64-bit box, using firefox 52. Math fonts look like "Times" font, and the vertical spacing was slightly better but still showing some over-spacing.

In all these cases, the exact same HTML file was used.


Mac and Windows did not show that symptom. Here's an example:

* test1-img.ffx-56-OSX.mac-laptop.png
On MacOS X, Firefox 56.


The same symptom seems to be exhibited on the following websites when rendered with recente Firefox/Linux setup:

http://asciidoc.org/latexmathml.html

https://www1.chapman.edu/~jipsen/mathml/asciimathdemo.xml

These do produce mathml at the end, after some preprocessing upon (re)loading the page.

(more image files will be uploaded separately)


Expected results:

No excessive vertical spacing should have been observed regardless where/with what fonts  the math is displayed.

Note: the HTML was produced using "asciidoc" and contains LatexMathML.js javascript. Since the render problem happens on some platform(s) but not other, and the only variation in these platforms are the browser version/OS environment, I conclude that the issue most likely rests on MathML rendering + interaction with OS-provided files (including fonts, in this case).

Comment 1

[Wirawan Purwanto]

Attachment: test1-img.ffx-ESR52-Linux-x86_64.wirawan2.png

Comment 2

[Wirawan Purwanto]

Attachment: test1-img.ffx-ESR52-Linux-x86_64.terry.png

Comment 3

[Wirawan Purwanto]

Attachment: test1-img.ffx-ESR52-Linux-x86_64.turing1.png

Comment 4

[Wirawan Purwanto]

Attachment: test1-img.ffx-56-OSX.mac-laptop.png

Comment 5

[Wirawan Purwanto]

Attachment: test1-img.ffx-57.0b6-linux-x86_64.wirawan2.png

Comment 6

[Isaac David]

I can confirm this. The issue is specially noticeable for inline formulas, as the excessive line spacing turns lines from a single paragraph into seemingly distinct paragraphs. Screenshot attached.

I first noticed this in Firefox 52.6, and I know it wasn't present in version 52.3.

Comment 7

[Isaac David]

Attachment: GNU+Linux_Firefox_52.6_MathML.png

Comment 8

[Frédéric Wang (:fredw)]

Hi all. Sorry for the late reply, but this is very likely a duplicate of bug 1208776 i.e. this is a bug in old math font and you (or your Linux distro) should upgrade them to the latest version.

Comment 9

[Frédéric Wang (:fredw)]

(In reply to Wirawan Purwanto from comment #0)
> On a debian8 64-bit box, using ESR firefox provided by Debian (Jessie). Math
> font style looks like "Computer Modern" font, and the vertical spacing was
> quite wild.

On Debian, Latin Modern Math has been upgraded in testing (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=799731) but Jessie still uses the old version.