[Webkit-unassigned] [Bug 167728] New: Poor MathML rendering on macOS Sierra with the system font

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=167728

            Bug ID: 167728
           Summary: Poor MathML rendering on macOS Sierra with the system
                    font
    Classification: Unclassified
           Product: WebKit
           Version: Safari 10
          Hardware: Macintosh
                OS: macOS 10.12
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: MathML
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: fred.wang at free.fr
                CC: bfulgham at webkit.org, darin at apple.com,
                    distler at golem.ph.utexas.edu, mitz at webkit.org,
                    mmaxfield at apple.com

Created attachment 300396
  --> https://bugs.webkit.org/attachment.cgi?id=300396&action=review
Screenshot of Mozilla's MathML Torture Test (STIXGeneral VS STIX Two)

By default macOS Sierra 10.12.3 only ships the obsolete STIXGeneral fonts, which are not enough to get decent mathematical rendering. On the other hand, STIX 2 was released in December 2016 and greatly improves the rendering when it is installed. See the attached screenshots comparing the two versions of STIX on Safari 10 (left: STIXGeneral, right: STIX Two):

- some vertical fences do no stretch to the desired size
- integrals and summation symbols are too small
- some scripts are wrongly placed
- vertical spacing in nested roots is too narrow
- probably more... See https://trac.webkit.org/wiki/MathML/Fonts for details.