Bug: line breaks in annotations are lost

Issue Summary

Reported on the MathJax user group.

If MathML annotations contain linebreaks, these are lost during processing.

Steps to Reproduce

1. Let the following render with MahJax

   <math>
   <semantics xref="p1.1.m1.1.cmml"><mo>Test</mo>
   
       <annotation encoding="application/x-tex">{\displaystyle{\displaystyle\sum_{k=1}^{\infty}\frac{\mathop{\zeta\/}\nolimits%
   \!\left(2k\right)}{k}z^{2k}=\mathop{\ln\/}\nolimits\!\left(\frac{\pi z}{%
   \mathop{\sin\/}\nolimits\!\left(\pi z\right)}\right)}}</annotation>
     </semantics>
   </math>

2. Check that Show Math => annotation => TeX gives

   {\displaystyle{\displaystyle\sum_{k=1}^{\infty}\frac{\mathop{\zeta/}\nolimits% !\left(2k\right)}{k}z^{2k}=\mathop{\ln/}\nolimits!\left(\frac{\pi z}{% \mathop{\sin/}\nolimits!\left(\pi z\right)}\right)}}

Similarly for showing the (non-original) MathML source.

This is a bug because it makes the annotations unusable.

Technical details

• MathJax Version: 2.3+