Bug 158310 - When exporting ODF to MML the infinity char (∞) is incorrectly exported as the Infinity html entity ∞ which is not valid XML
Summary: When exporting ODF to MML the infinity char (∞) is incorrectly exported as th...
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Formula Editor (show other bugs)
Version:
(earliest affected)
7.2.0.0 alpha1+
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: bibisectNotNeeded, regression
Depends on:
Blocks:
 
Reported: 2023-11-22 07:15 UTC by sam.monsarrat
Modified: 2025-11-22 03:13 UTC (History)
0 users

See Also:
Crash report or crash signature:


Attachments
ODF file containing a ∞ char (4.81 KB, application/vnd.oasis.opendocument.formula)
2023-11-22 07:15 UTC, sam.monsarrat
Details

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Description sam.monsarrat 2023-11-22 07:15:09 UTC
Created attachment 190953 [details]
ODF file containing a ∞ char

MathML is meant to be valid XML.

In certain conditions LibreOffice Math exports the infinity char (∞) as the Infinity html entity ∞ which is not valid XML rendering the prodiced MML file useless.

Consider the attached formula.odf file. When LibreOffice exports it to MML :

 * line 9 of content.xml : <mi mathvariant="normal">∞</mi>
 * is exported as <mi mathvariant="normal">&infin;</mi>

The produced file is not valid XML and will not load in a browser.
Comment 1 Mike Kaganski 2023-11-22 08:22:34 UTC
This is not a bug.

MathML is not only a "valid XML"; it also references the MathML specification. Namely:

MathML spec. chapter 7 section 7.3 "Entity Declarations" [1] tells:

> The MathML DTD references the combined HTML MathML entity set defined in [Entities]

The "combined HTML MathML entity set" [2] references, among others, "xhtml1-symbol" set.

The latter is defined in "Entities" [3] as [4]. And there, the 'infin' entity is defined.

It is incorrect to expect parsing of MathML without the respective DTD.

[1] https://www.w3.org/TR/MathML3/chapter7.html#chars.entities
[2] http://www.w3.org/2003/entities/2007/htmlmathml.ent
[3] https://www.w3.org/TR/xml-entity-names/
[4] https://www.w3.org/TR/xml-entity-names/xhtml1-symbol.html
Comment 2 Mike Kaganski 2023-11-22 08:40:43 UTC
OTOH:

> every fragment using entity references must use a DOCTYPE declaration which
> specifies the MathML DTD, or a DTD that at least declares any entity reference
> used in the MathML instance

NEW.
Comment 3 Mike Kaganski 2023-11-22 08:54:04 UTC
Regression after https://gerrit.libreoffice.org/c/core/+/108354.
Comment 4 sam.monsarrat 2023-11-22 09:23:40 UTC
Why then does the internal MathML in content.xml not use them ?
Why produce an MML file that no browser can parse ?
The produced MML cannot be displayed by mozilla or chromium browsers.

This problem is not present on LibreOffice 6.4.7.2
Comment 5 QA Administrators 2025-11-22 03:13:44 UTC
Dear sam.monsarrat,

To make sure we're focusing on the bugs that affect our users today, LibreOffice QA is asking bug reporters and confirmers to retest open, confirmed bugs which have not been touched for over a year.

There have been thousands of bug fixes and commits since anyone checked on this bug report. During that time, it's possible that the bug has been fixed, or the details of the problem have changed. We'd really appreciate your help in getting confirmation that the bug is still present.

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