`dissected_length` can come from the packet in some paths, meaning it can be 0
or negative and we need to check for underflows and other such problems
Bug: 11255
Change-Id: Iba55ec1824a391ec1c717bfea5b65cc6610fc081
Reviewed-on: https://code.wireshark.org/review/8839
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Evan Huus <eapache@gmail.com>