Segmentation fault with pdf with comments

[lfoppiano]

Originally from this issue https://github.com/kermitt2/grobid/issues/241

(base) [Luca@falcon lin-64]$  ./pdfalto_server  -fullFontName -noLineNumbers -noImage -annotation -filesLimit 2000 /tmp/TUW-217619.pdf /tmp/TUW-217619.alto.xml  --timeout 50
Segmentation fault

(base) Lucas-MacBook-Pro:mac-64 lfoppiano$ ./pdfalto_server  -fullFontName -noLineNumbers -noImage -annotation -filesLimit 2000 ~/Downloads/TUW-217619.pdf 
Segmentation fault: 11

Documents:

• TUW-217619.pdf (fails)
• TUW-217619_without_comments.pdf (works)