Add unit tests.
* src/engine/imap/transport/imap-deserializer.vala (Deserialiser): Add a
new EOL even handler to the FAILED state that is the one place where
the deserialize_failure() signal is fired and that any existing params
are reset.
(Deserialiser::push_line): Remove signal calls and unused return
value. Don't use EOS to detect NUL to avoid some confusion. Ensure an
EOL event is always fired so that the FAILED EOF handler is always run.
(Deserialiser::push_data): Remove signal calls and unused return value.
(Deserialiser::flush_params): Don't bother returning a state, since we
now always know what the next one should be when calling it. Only
trigger the parameters_ready() signal if there is a valid
parameter. Make logging consistent with the rest of the class.
(Deserialiser::reset_params): New common method for resetting any
existing deserialised message.
(Deserialiser::on_literal_char): Minor tidy up.
(Deserialiser::on_eos): Ensure that any existing param is sent on EOS
so that any BYE+EOS sent by the server is picked up.
Fixes Bug 781488.
* src/engine/imap/transport/imap-deserializer.vala (Deserializer): Update
char handling in START_PARAM state to be more explict and to handle all
possible chars, not just a subset. Then, simply defer to START_PARAM to
determine what to do when an invalid atom char is encountered when in
the ATOM state. Rename SYSTEM_FLAG state to just FLAG since it also
handles extension flags, and only use it for handling the first char in
the flag so "\*" can be treated appropriately, then defer to the ATOM
state, so flag keywords are treated in the same way as regular
atoms. Add unit tests.
