if the past we had lots of crashes because of unexpected unwrap failures,
mostly related to string.
this commit avoids them eg. for string-conversions that may panic
eg. when encountering a null-byte or by logical programming errors
where an object is assumed to be set but is not under unexpected circumstances.
* add sticker type
this pr adds the message type 'sticker'.
stickers are handled as normal images
but tagged with the header `Chat-Content: sticker`
it's up to the ui to render these stickers appropriate.
* cargo fmt
This adopts the FFI API to use the new Context::new() and
Contest::drop() Rust-style APIs while preserving the semantics of the
existing FFI API. It introduces a wrapper around the context which
keeps an optional reference to the actual context, changing dc_open()
and dc_close() to create/destroy the actual reference.
This changes the events emitted on closing slightly: they only get
emitted when dc_close() was called while the context was open. While
dc_close() remains idempotent in that it can still be called safely
multiple times, the close events will only occur if the context is
actually closed.
A new context is now created by calling Context::new and therefore you
always have a valid context. This is much more in Rust style and will
allow a lot of furture simplifications on the context itself.
The FFI layer has not yet been adjusted in this commit and thus will
fail.
* refactor(contact): rename and rusty memory allocations
* refactor(contact): use enum to indidcate origin
* refactor(contact): safe blocking and unblocking api
* refactor(contact): only safe and no more cstrings
