XeTeX with TeX fonts is only safe with ASCII input encoding (see #9740)
and we therefore force "ascii" when exporting with XeTeX and 8-bit TeX-fonts.
However, "utf8-plain" is a "power-user" option, which allows to switch off LyX's
encoding of the LaTeX file:
keep this also for "XeTeX with TeX fonts".
The user is responsible to ensure all characters can be processed and are
correctly shown in the output. The provided test sample shows the problems
with this encoding without special measures (like loading fontspec in the
user-preamble or a document class).
We test here, if any \end_{somethig} matches \begin_{something}.
Exeptions are \end_index and \end_branch ATM, they should
match \index and \branch respectively.
Also added new testfile.
To omit the error, there are 2 possibilities
1.) Change \inputencoding to utf8-platex
or
2.) write some text in default language prior to the following
subchapter 1.2.2
Probably a candidate for language nesting
This works around a limitation of the test machinery, which never switches
TeX fonts on for format that need that, it only switches TeX fonts off for
formats needing it.
Thanks to Kornel we do now have the infrastructure for running dedicated
export tests. This is the first one, showing a language nesting bug which is
already in 2.1. It is inverted for now, but this will hopefully change soon.
