lib-imap-client: Change server IP only on connect() failures Also log an warning-level message about it. This is mainly useful to see that a slow connection could be caused by a connect() timeout. Since more IPs are still available, it's not yet an error.

imapc: Fix infinite reconnection when server keeps sending corrupted state When corrupted state was found, imapc_client_mailbox_reconnect() is called to reconnect. This call skipped the normal "is it safe to reconnect?" checks causing potentially infinite reconnections.

lib-imap-client: Remove hardcoded IMAPC_CONNECT_RETRY_WAIT_MSECS We have a setting for it now.

lib-imap-client: Call the public login callback exactly once. Previously it was also called only once, as long as there were only a single imap connection. (The current imapc code wouldn't create more than one connection.) It was a bit confusing what the expectation was, so now the callback is never called more than once.

imapc: Use LOGOUT to cleanly disconnect from server. This makes it clearer in the remote server's logs whether the disconnection was intentional or not. Use a hardcoded 5 second timeout for LOGOUT. It should be enough time for the server to finish sending the tagged reply.

imapc: Fix re-sending retryable commands after reconnect

imapc: Support retrying after connect() failure.

imapc: Prepare for non-mailbox command retrying: Set reconnect_command_count earlier This probably doesn't fix itself anything yet, but is needed for the following changes.

lib-imap-client: Allow reconnecting to IMAP server even if there had been no idle moments.

imapc: Added throttling settings to imapc_features=throttle:a:b:c This change could be reverted once good settings are found.

imapc: Fixed crashes during mailbox close.

Marked functions parameters that are allowed to be NULL. Some APIs were also changed. The non-obvious APIs where NULL parameter was changed to "" are master_service_init() and auth_master_user_list_init(). These checks can currently be enabled only on a patched clang: http://llvm.org/bugs/show_bug.cgi?id=6786

imapc: Fixed reopening a mailbox.

imapc: Support retrying some IMAP commands if we get disconnected.

imapc: Initial support for automatically reconnecting to remote server.

imapc: Changed mailbox opening API to be more extensible.

imapc: Command sending API changed to be more extensible.

Moved imapc-client into its own lib-imap-client library.