aa-mergeprof: crash in ask_the_question() when calling profile_known_network()

aa-mergeprof around line 710, in ask_the_question():

            for allow in ['allow', 'deny']:
                for family in sorted(other.aa[profile][hat][allow]['netdomain']['rule'].keys()):
                    # severity handling for net toggles goes here

                    for sock_type in sorted(other.aa[profile][hat][allow]['netdomain']['rule'][family].keys()):
                        if apparmor.aa.profile_known_network(self.user.aa[profile][hat], family, sock_type):
                            continue

The apparmor.aa.profile_known_network() call crashes aa-mergeprof with:

# python3 ~/apparmor/HEAD-CLEAN/utils/aa-mergeprof -d ../../INSTALL/ usr.sbin.couriertls

 Merging profile for /usr/sbin/couriertls
 Traceback (most recent call last):
   File "/home/cb/apparmor/HEAD-CLEAN/utils/aa-mergeprof", line 809, in <module>
     main()
   File "/home/cb/apparmor/HEAD-CLEAN/utils/aa-mergeprof", line 113, in main
     act([user_file, base_file, None], 2, profile_name)
   File "/home/cb/apparmor/HEAD-CLEAN/utils/aa-mergeprof", line 150, in act
     mergeprofiles.ask_the_questions('base', merging_profile)
   File "/home/cb/apparmor/HEAD-CLEAN/utils/aa-mergeprof", line 727, in ask_the_questions
     if apparmor.aa.profile_known_network(self.user.aa[profile][hat], family, sock_type):
   File "/home/cb/apparmor/HEAD-CLEAN/utils/apparmor/aa.py", line 4444, in profile_known_network
     if netrules_access_check(include[incname][incname]['deny']['netdomain'], family, sock_type):
 KeyError: 'abstractions/base'

The reason for the crash is that profile_known_network() in aa.py expects the global variable 'include' to be filled, but it's empty at this time.

By disabling the profile_known_network() call, aa-mergeprof asks for network rules that are in the "new" profile, but already covered by an abstraction. This doesn't hurt much because the cleanprof run at the end removes them again ;-)

(Note to myself: this is easily reproducable with the profiles from da2.)