Disallow comment fields larger than 10 MB

Otherwise we might allocate a lot of memory and create a OOM situation
for malformed or malicious files.

Issue: FP2P-556
Change-Id: I963f1b8b271ee67c1255276cf17a8f59388bccea
(cherry picked from commit a435e082f54d336e4e07cf47e3e906bfd65faf86)
1 file changed