This is a long running process and there has been at lease one crash
in this function. By owning both the context and the provider when
waiting we can avoid them being deallocated while we are still using
them.
To make the BackupProvider clonable this transforms all the errors
from it into Strings. These are clonable and how we report most our
errors anyway. The Future impl of BackupProvider then turns this into
an anyhow::Error so all other code can keep using anyhow as usual.
The documentation says this blocks. This should block because it also
means the error reporting is more accurate by calling set_last_error
just before returning.
Otherwise it is possible for the context that is used in the spawn to
be unreferenced. Really this should be caught by the borrow checker
that ensures we only spawn things with a 'static lifetime, but we're
handling raw pointers so it doesn't.
This adds a result extension trait to explicitly set the last error,
which *should* be the default for the FFI. Currently not touching all
APIs since that's potentially disruptive and we're close to a release.
The logging story is messy, as described in the doc comment. We
should further clean this up and tidy up these APIs so it's more
obvious to people how to do the right thing.
This fixes use-after-free in case dc_context_unref() is called
while the background process spawned by dc_configure() is still
running.
Corresponding regression test in Python can be run with
`pytest tests/test_1_online.py::test_configure_unref`.
This also removes BackupProvider::join in favour of implementing
Future directly. I wondered about implementing a FusedFutre to make
this a little safer but it would introduce a dependency on the futures
crate in deltachat-ffi which did not exist yet, so I didn't do that.
get_chat_msgs() function is split into new get_chat_msgs() without flags
and get_chat_msgs_ex() which accepts booleans instead of bitflags.
FFI call dc_get_chat_msgs() is still using bitflags for compatibility.
JSON-RPC calls get_message_ids() and get_message_list_items()
accept booleans instead of bitflags now.
This adds functionality to send and receive a backup over the network
using a QR code.
The sender or provider prepares the backup, sets up a server that
waits for clients. It provides a ticket in the form of a QR code
which contains connection and authentication information.
The receiver uses the QR code to connect to the provider and fetches
backup, restoring it locally.
