[luatex] \enddir

[Joseph Wright]

Hello all,

If you insert something like

  \hbox{\textdir TRT ABC}

and look at the shipout, you get

  ..\hbox(6.83331+0.0)x21.8056, direction TLT
  ...\begindir TRT
  ...\tenrm A
  ...\tenrm B
  ...\tenrm C
  ..\glue 0.0 plus 1.0fill

On the other hand, adding a group

  \hbox{{\textdir TRT ABC}}

leads to

  ..\hbox(6.83331+0.0)x21.8056, direction TLT
  ...\begindir TRT
  ...\tenrm A
  ...\tenrm B
  ...\tenrm C
  ...\enddir TRT
  ..\glue 0.0 plus 1.0fill

which includes an \enddir. Both of these seem to work the same way in
practice (the direction does not 'leak' from the first case), but I
wonder if the \enddir has any importance.

For testing, I tried

  \hbox{\textdir TRT ABC\textdir TLT D}

which gives the slightly odd

  ..\hbox(6.83331+0.0)x29.4445, direction TLT
  ...\begindir TRT
  ...\tenrm A
  ...\tenrm B
  ...\tenrm C
  ...\begindir TRT
  ...\begindir TLT
  ...\tenrm D
  ..\glue 0.0 plus 1.0fill

(Can't imagine this is deliberate.)
-- 
Joseph Wright