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`.
dc_configure() spawns a background configuration process.
It should increase the number of context references
so even if we unref the context, it is not dropped
until the end of the configuration process.
Currently running the test
with `pytest tests/test_1_online.py::test_configure_unref`
results in segmentation fault.
`<meta name="color-scheme" content="light dark" />` is a hint to the browsers
that the page can be rendered in light as well as in dark mode
and that the browser can apply corresponding defaults.
as we do not add css colors on our own,
this is sufficient for letting generated html messasge being rendered
in dark mode.
cmp. https://drafts.csswg.org/css-color-adjust/#color-scheme-propcloses#4146
standard footers meanwhile go the "contact status",
so they are no longer a reason to trigger "full message view".
this was already discussed when the HTML view was introduced at #2125
however, forgotten to change when the "contact status" was added at #2218
this pr will result in a cleaner chat view
with less "Show Full Message..." buttons
and will also save some storage
(in fact, i came over that when reviewing #4129 )
the contrast was decreased at
https://github.com/deltachat/deltachat-core-rust/pull/4136 ,
there were also suggestions to fix it there,
but it was probably just forgotten :)
this pr increases the contrast
between code background and code font again to the level it was before
and also to what similar themes are doing.
We are currently using libsqlite3-sys 0.25.2,
corresponding to SQLcipher 4.5.2
and SQLite 3.39.2.
SQLite supports ALTER TABLE DROP COLUMN since version 3.35.0,
and it has received critical database corruption bugfixes in 3.35.5.
There have been no fixes to it between SQLite 3.36.0 and 3.41.0,
so it appears stable now.
Explicit `prepare_msg` corresponding to `dc_prepare_msg`
is intended only for the case where the message is prepared
before the file is ready. It is not indented for calling
right before send_msg and requires that file path in the blobdir.
With explicit `prepare_msg` removed
all the tests still pass but there is no requirement
that the file is put into blobdir beforehand.
This adds more configuration to cargo-deny so that the output is not a
giant list of warnings hiding new entries. Instead the config now
lists the things that would emit warnings. It also adds -Dwarnings to
the CI job so that new warnings will be cleaned up: they can be added
to the config easily to fix the warnings.
We do not make all transactions
[IMMEDIATE](https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions)
for more parallelism -- at least read transactions can be made DEFERRED to run in parallel
w/o any drawbacks. But if we make write transactions DEFERRED also w/o any external locking,
then they are upgraded from read to write ones on the first write statement. This has some
drawbacks:
- If there are other write transactions, we block the thread and the db connection until
upgraded. Also if some reader comes then, it has to get next, less used connection with a
worse per-connection page cache.
- If a transaction is blocked for more than busy_timeout, it fails with SQLITE_BUSY.
- Configuring busy_timeout is not the best way to manage transaction timeouts, we would
prefer it to be integrated with Rust/tokio asyncs. Moreover, SQLite implements waiting
using sleeps.
- If upon a successful upgrade to a write transaction the db has been modified by another
one, the transaction has to be rolled back and retried. It is an extra work in terms of
CPU/battery.
- Maybe minor, but we lose some fairness in servicing write transactions, i.e. we service
them in the order of the first write statement, not in the order they come.
The only pro of making write transactions DEFERRED w/o the external locking is some
parallelism between them. Also we have an option to make write transactions IMMEDIATE, also
w/o the external locking. But then the most of cons above are still valid. Instead, if we
perform all write transactions under an async mutex, the only cons is losing some
parallelism for write transactions.
