Non-ASCII symbol causes error

[trinker]

A copy from an email from Florian.Schwendinger@wu.ac.at

I was trying your hunspell package and i recognized,
that if there is a EURO symbol in the text
make_lemma_dictionary gives an error.

make_lemma_dictionary("some text with € symbol", 
                      engine = "hunspell", lang = "de_AT")
## Error in R_hunspell_stem(dictionary, words) : 
##   basic_string::_M_construct null not valid

I found the same behavior for

c("€", "…", "“", "„")

I am not sure if this is the intended behavior,
but if not it would be maybe the easiest if
you run intToUtf8 for some reasonable sequence
and exclude all the symbols which cause trouble.