texi2any garbles some unicode chars

[Alexander Gromnitsky]

Hello,

I've made a "diagram" using Emacs artist-mode & have transformed it
into a unicode version using ascii-art-to-unicode [0] pkg.

When I convert a .texi file:

  \input texinfo
  @settitle NAME-OF-MANUAL
  @node Top

  @example
  ┌───────┐
  │ hello │
  └───────┘
  @end example

  @bye

into the .info format, it renders as expected:
https://ultraimg.com/images/2017/12/24/n1TI.png

but in the html output I see garbage (texi2any --html --no-split
--no-headers unicode.html):
http://chunk.io/gromnitsky/c75c4ad225104c6b807e072acb38f499

I've been using the latest texinfo version from svn.

[0]: ELPA or http://www.gnuvola.org/software/aa2u/