up to now, Chat-Group-Member-Added and -Removed commands
result in a complete recreation of the memberlist
by collecting all addresses from the From: and To: headers.
this easily results in missed and accidentally removed members,
esp. when several people at the same time scan a qr code to join a group.
this commit changes the behavior of adding members by
not removing members on the Chat-Group-Member-Added command.
instead the existing memberlist is conjuncted
with the memberlist seen in the message.
only adding the member from the Chat-Group-Member-Added
seems not to be sufficient - imaging a group of Alice and Bob:
- Alice adds Claire
- Bob adds Dave _before_ seeing that Alice added Claire
- Dave would never get the information that Claire is in the group
wrt Chat-Group-Member-Removed: this command
does no longer recreate the memberlist but just remove _exactly_ the member
mentioned in the header. there are situations, where a just removed member
will be readded by out-of-order-messages, however, compared to missed
members, this is seems to be acceptable - also as this is more visible
and easier to fix (just remove the member again).
might be that, in practise, this is not a big issue. while adding members
is typically done in masses on bootstraping a group,
this is typically not true for removing members.
Instead, use last_insert_rowid() function to find the row.
There is no race condition in using last_insert_rowid(), because
last_insert_rowid() returns row id last inserted in this connection. As
we hold the connection during the whole transaction, it is impossible
that some other thread will execute INSERT statement in parallel.
This commit is part of the effort to get rid of sql::get_rowid hack and
use transactions more for related SQL statements.
Existing public methods that use these functions, like sql::execute, are
only suitable for executing a single statement.
Sometimes it is useful to execute multiple statements within one
connection, for example to begin a transaction, execute mutliple SELECT
and INSERT queries and commit or rollback the whole transaction.
We already have a .strdup() method on AsRef<str>, this adds this
method also to an option of this. In case the option is None a NULL
pointer is returned.
This is done by using a new trait, as the type system otherwise
considers such an implementation conflicting with the existing one.
Now configure module is no longer public. Users should call
Context.configure() and Context.is_configured() methods.
Configure module is completely hidden from documentation unless
--document-private-items option is specified.
