Shorter.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Add cacert option for curl plugin

    add cacert option for Curl plugin. Allows to set cacert for curl lib
    Added documentation line into doc/plugins.rst with explanation for cacert option

I havn't yet figured out how to use Android's system CA certificates
with CURL/OpenSSL, so a temporary workaround is to disable verify_peer
by default.  The data MPD transfers isn't extremely important, so the
servers's authenticity isn't extremely important either.

Found with cppcoreguidelines-interfaces-global-init
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Shorter.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

My concept with `class CancellableOperation` doesn't work properly,
because the kernel may continue to write to the given buffer as soon
as the read finishes.

To fix this, this commit adds `class ReadOperation` which owns the
buffer and the `struct iovec`.  Instances of this class persist until
the read really finishes, even if the operation is canceled.

Same as e10b867f but it got lost in
the merge, because the v0.22 branch uses a different way to detect
supported protocols at runtime.

FFmpeg implements RTSP as a demuxer, not as a protocol handler.  Thus,
avio_open() cannot be used, and our input plugin cannot handle RTSP.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/930

This is no longer necessary with the new API.

As a side effect, the input plugin closes the SMB/CIFS connection
after closing the file.

This solves one part of
https://github.com/MusicPlayerDaemon/MPD/issues/916

`LogLevel::INFO` is logged by default, but this message shall only
appear with `--verbose`.

This finally solves https://github.com/MusicPlayerDaemon/MPD/issues/430

Stop bothering people about the Tidal/Qobuz plugins.

A bug report (https://github.com/MusicPlayerDaemon/MPD/issues/912)
suggests that on Linux, reading on `cifs` files may rarely return 0 (=
end of file) before the end of the file has really been reached.  But
that's just a theory which I need to validate, so this runtime check
shall catch this condition before the assertion in
DecoderBridge::Read() crashes MPD.  Let's see.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/912

The ones in std have overloads for const char/char.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Some more `-Wpedantic` fixups.

This is the final piece of the series to establish io_uring support on
Linux.

MPD doesn't need io_uring for its efficient bulk I/O support, but to
allow file I/O to be cancelled.  This is a big problem on CIFS/NFS
mounts where processes sleep uninterruptable if the file server
disappears, deadlocking MPD.

With io_uring, a flaky NFS connection allows MPD to continue to work
(even though there are still deadlocks inside MPD which need to be
addressed).

This plugin does not yet use cancellable `open()` using
`IORING_OP_OPENAT`.  This will be implemented later.

Lots of other optimization opportunities for io_uring are still
missing as well - for example the database update could benefit a lot,
but unfortunately, io_uring doesn't have `readdir()` support just yet.

This makes ccache more efficient when recompiling with different
plugins.

Fixes regression by commit 015cbff9 causing a crash bug because the
iterators of two different temporaries were used.

std::all_of becomes constexpr in C++20. I'm not sure it results in better
performance.

Found with useStlAlgorithm
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with readability-uppercase-literal-suffix
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Signed-off-by: Rosen Penev <rosenp@gmail.com>