Security: Missing range checks on comment processing, handling missed spots.

Security: Missing range checks on comment processing, handling missed spots.

I failed to perform all of the changes when I backported commit 27c0bbafc2c0f3ae49c0e45297a2dc9f82c11221 via commit 1898cbbc7e92dfafb1e2fa3538284442e21c3879.

The while loop is being checked for the comments length.
The if condition immediately outside that is not being checked.
This check is being performed in the original commit that I backported from.
This is simply a backporting oversight.