#197 hfst-twolc segfaults on simple grammar

[Flammie Pirinen]

While testing space handling in twolc, following grammar made it segfault:

Alphabet
% A % A:0

;

Rules
"after A"
% A:0 <=> % A _ ;

Using:

$ hfst-twolc spacen-bug.twolc 
Reading input from spacen-bug.twolc.
Writing output to STDOUT.
Segmentation fault

syntax error, unexpected $end
on line 1:

Aborted.

Software versions from hfst.ling.helsinki.fi