Peter M. Groen / FlashMQ

When the plugin was enabled, it would never got past the fail of not
having a password file entry. This is fixed.

The reauth didn't work because setting the return data took the path of
first auth, hitting a protection exception. This is fixed.

Writing extended auth tests involved some refactoring, to create a
separate method to parse the auth packet data, because I needed it in
the test too.

Also fix sending an UNSUBACK instead of SUBACK on unsubscribe.

Only split when they're needed, instead of pre-determining whether I'll
need the subtopics.

This makes the coming refactor of authentication easier.

Also treated user properties with the same brush a bit. Downside: it now
always assigns user properties to newly constructed publish objects,
even if they are not needed (because the generated packet may only be
needed for writing to the client's output buffer). But determining the
flow of when and when not they'll be needed is impossible with the
coming authentication refactor.

The order packets would (mostly) arrive, is 'retained publish', then
'sub ack'. This is now fixed.

This also stablizes test_retained_changed(). The test was also
refactored to use the new test client.

Now that parsing and handling of packets is separated, we can use the
main code to parse packets in the new FlashMQTestClient. This allows
great flexibility in inspecting the server response in a flexible
manner.

We now also have the ability to make tests for MQTT5 features.

Will be used for the test client I have in mind.

Will be used for the test client I have in mind.

This is necessary for the test client I have in mind, so I can re-use
this code in that new test client which has no MQTT behavior, but just
returns packets (meaning I have to be able to parse them without
initiating handling).

This is necessary for the test client I have in mind, so I can re-use
this code in that new test client which has no MQTT behavior, but just
returns packets (meaning I have to be able to parse them without
initiating handling).

And also to future parse... methods.

This is necessary for the upcoming new test client.

This also contains some fixes/unifications for traditional
authentication, error handling specifically.

Also fix some bugs:

- The password can be binary data.
- The will topic is now also checked.

It went over boundry when there were no properties.

Also changed will logic in disconnect: only clear it when it's a
successful disconnect.

And the TODOs are for the next thing: saving the createdAt date.

This prevents bugs because the calling context forgets it. A (small)
downside is that I have to make the Publish argument non-const. But,
that's exactly what it is then, so...

Also fixed a length check bug.

Because clients can now also exist as dummy objects, I had to add some
extra checks.

Also split up handlePublish() and the new parsePublishData().

I'm not sure how I'm continueing. I need a safe point.

I'm simplying/merging the rec, comp and rel packets, but I'm not sure it will
work. Committing as a safe point.

Later: I got it done as planned. Testing qos > 0 and mqtt5 still needs
to be done more.

And one line about correlation data that was a bug.

I need to decide what to do with getPublishData

and that disabled test needs repurposing.

which also has implications on how I think to handle 'queuePacketAtSub'

Most of it is limits we already implemented non-standard compliant.

For the coming MQTT5 support, I'll need this a lot.

This is a preparation for MQTT5, because when there are receivers and
publishers with different protocols, you can't always just write out the
same packet. You can sometimes though, so that's what the copy factory
determines.

This entails making copies of the original packet when necessary,
because QoS 0 doesn't have a packet id. I tried to keep it to an
absolute minimum and do some precarious optmizations for it. There are
tests though.

This makes more sense, logically, and also helps in tests I'm about to
write.

It caused typical global variable issues, showing in the retained
messages recursive alghorithm breaking, because the referenced subtopics
changed half way (see previous commit of the test for it).

I need to perform some benchmarks to see if I need to devise an
alternative.

Files are simple serialized bytes prefaced by lengths. File is hashed to
verify integrity. This was also a good way preventing unexpected errors
when trying to crash the parser by having it load a different file.

This change includes some refactoring that was necessary:

- It 'fixes' looking at the wrong thread's authentiction. This is still
  wrong though. It will be fixed by a thread local pointer in the next
  commit.
- Deadlocks with yourself are handled in rwlockguard.
- QoSPacketQueue is now a class.
- Probably other tweaks.