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Issue created by Administrator@rootContributor

Problem with MathJax 2.7.5 and Chrome >= 76.0.3809.132 for MathJaX inside an RTL DIV

Created by: taniwallach

Issue Summary

When Chrome 76.0.3809.132 is used to render MathJaX content inside an right-to-left (RTL) DIV element using MathJax 2.7.5 problems occur with the placement of the mathematics. The mathematics is often displayed on the incorrect side of the Hebrew (RTL direction) text.

These problems were originally found in WeBWorK problems rendered using MathJax 2.7.5 (not from the CDN) late last week.

The earlier report of trouble dates to Sept 4 from a Windows user.

MathJax 2.7.5 behaves properly when the prior version of Chrome (76.0.3809.100 on Windows) is used, and the problems was seen to immediately begin as soon as Chrome was updated on a machine which had an running copy of Chrome 76.0.3809.100 on Windows. (Since Chrome auto-updates, but does not restart the updated version, it requires some luck to see this.)

These problems do not occur when MathJax 2.7.4 is used even with Chrome 76.0.3809.132.

On my main (Debian 10) machine - I originally did not have these problems immediately after the update to Google Chrome 76.0.3809.132, and they began to occur only on about Sept 7. It may be possible that a cached version of MathJax.js was responsible for the delayed appearance of the issue.

The Chrome update includes changes to the Blink rendering engine, and something in these 2 updates (Chrome 76.0.3809.100 to 76.0.3809.132 and MJ 2.7.4 to 2.7.5) triggers the problems.

The issues has been seen on Windows 10, Windows 8, Debian 10, Android 6.0.1 - all when running Chrome 76.0.3809.132.

Steps to Reproduce

Test pages:

Symptoms:

  • Initial page load (uses the default HTML-CSS math renderer: the math is incorrectly displayed at the far right, while it is logically located at the end of a right-to-left line so should be on the left side of the Hebrew text.
  • Changing the Math Renderer (Context menu -> Math Settings -> Math Renderer) to Common HTML and the math moves to the left (where it should be)
  • but then after a page refresh it moved back to the right side (incorrect location)
  • Changing the Math Renderer back to HTML-CSS and the math moves to the left (where it should be)
  • but then after a page refresh it moved back to the right side (incorrect location)
  • Changing the Math Renderer to SVG and the math moves to the left (where it should be)
  • but then after a page refresh it moved back to the right side (incorrect location)
  • Changing the Math Renderer back to HTML-CSS and the math moves to the left (where it should be)
  • but then after a page refresh it moved back to the right side (incorrect location)
  • Sometimes the math is seen to appear briefly in the correct location (left side) before disappearing and reappearing on the right side (incorrect location)
  • In some cases, fiddling with these settings and refreshing lead to multiple math displays or the math disappearing from the page.

No such trouble was detected using FireFox or Edge.

Several screen shots will follow.

Technical details:

  • MathJax Version: 2.7.5 (from the CDN)
  • Client OS: Debian 10, Windows 10, Windows 8, Android 6.0.1
  • Browser: Chrome 76.0.3809.132