Additionally, it *may* have caused document corruption when loading such an
.xlsx file, though a small test case with an embedded literal tab character
could not reproduce the behaviour.
See
https://ask.libreoffice.org/en/question/100615/sudden-corruption-of-xlsx-file-bug/
and note that the literal tab character is a mere assumption, but it would be
possible.

Change-Id: Ia9d33955f1196222d335a1a4807fba78df4e4d85