All protocol handler structs are now opaque (void *) in the
SessionHandle struct and moved in the request-specific sub-struct
'SingleRequest'. The intension is to keep the protocol specific
knowledge in their own dedicated source files [protocol].c etc.
There's some "leakage" where this policy is violated, to be addressed at
a later point in time.
1 - always allocate the struct in protocol->setup_connection. Some
protocol handlers had to get this function added.
2 - always free at the end of a request. This is also an attempt to keep
less memory in the handle after it is completed.
Removed the hard returns from imap and pop3 by using the same style for
sending the authentication string as smtp. Moved the "Other mechanisms
not supported" check in smtp to match that of imap and pop3 to provide
consistency between the three email protocols.
Following commit e450f66a02 and the changes in the multi interface
being used internally, from 7.29.0, the transfer cancellation in
pop3_dophase_done() is no longer required.
Moved the blocking state machine to the disconnect functions so that the
logout / quit functions are only responsible for sending the actual
command needed to logout or quit.
Additionally removed the hard return on failure.
Some state changes would be performed after a failure test that
performed a hard return, whilst others would be performed within a test
for success. Updated the code, for consistency, so all instances are
performed within a success test.
Removed this pointer to a downloaded bytes counter because it was set in
pop3_init() to point to the same variable the transfer functions keep
the count in (k->bytecount), effectively making the code in transfer.c
"*k->bytecountp = k->bytecount" a no-op.
Updated the mailbox variable to correctly reflect it's purpose. The
name mailbox was a leftover from when IMAP and POP3 support was
initially added to curl.
Removed user and passwd from the POP3 struct as these cannot be set on
a per-request basis and are leftover from legacy FTP code.
Changed some comments still using FTP terminology.
Moved the mailbox and custom request variables from the per-connection
struct pop3_conn to the new per-request struct and fixed references
accordingly.
... since they're not used by the easy interface really, I wanted to
remove the association. Also, I unified the pingpong statemachine driver
into a single function with a 'wait' argument: Curl_pp_statemach.
A call to Curl_ssl_connect() was accidentally left in when the SSL/TLS
connection layer was reworked in 7.29. Not only would this cause the
connection to block but had the additional overhead of calling the
non-blocking connect a little bit later.
