[REVIEW-3-5] Fix for crash in fdo#50868

[Fridrich Strba]

I would love to have review for these two patches for 3.5.5.

The first one upgrades libvisio to version 0.0.17 that we have in the 
3.6 branch and the second patches that libvisio version to avoid crashes 
with empty text data.

http://cgit.freedesktop.org/libreoffice/core/commit/?id=3f723b36c404374dcf10c347d913f8e3cba93fae
http://cgit.freedesktop.org/libreoffice/core/commit/?id=e71749a089fa3e6463b80413b638f7dc32921a07

Useful, but not compulsory to fix fdo#50868 is the following patch

http://cgit.freedesktop.org/libreoffice/core/commit/?id=7575ebe35f6af1cc58e95a804087e7c1e0f06eee

It prevents dereferencing of &vec[0] when vec.empty(). It is an 
additional check to prevent the kind of crashes like in fdo#50868.

Thanks for careful review, because it is a bit late :)

Fridrich


-- 
Please avoid sending me Word, Excel or PowerPoint attachments.
See http://www.gnu.org/philosophy/no-word-attachments.html