[XeTeX] additional beginL endL nodes in math

[David Carlisle]

Is there no other way that the issues you have could be addressed
without introducing TeX-XeT?

The more we look at this the more it seems a very unfortunate step,
introducing several incompatibilities
with pdftex and luatex.

Especially if there is a possibility of moving in the end to an
Omega/luatex model for bidirectional support
introducing a change at this point seems a strange choice.

The extra nodes added here really are a backward step, my first
suggestion of only conditionally
adding them doesn't really work if boxes containing math are saved and
used in different contexts.

Especially now in the Texlive 2015 pretest period there is so little
time to test any
changes.

Would it be possible to back it out this change at least until after
TL2015 is released
That would give time to investigate a more compatible way to address the issues?


David