Prepare to fix cc72ceb3

Also include fade-out time in song length.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/838

This reduces resource waste for resizing the std::vector in most
cases.

Optimizes a few nanoseconds from the common code path.

release v0.21.23

libnfs is compiled with `-D_FILE_OFFSET_BITS=64`, but Meson decides
not to enable this mode.  We could force this mode, but then again,
these days, nobody should be using 32-bit Windows ... so this is a
kludge only for debugging with 32-bit WINE.

Fixes Path::IsNull() checks on Windows.

This fixes a freeze bug in the NFS input/storage plugins: when libnfs
auto-reconnets after a failure, it installs the new socket on the same
file descriptor number.  MPD's attempt to unregister the old socket by
calling SocketMonitor::Steal() from NfsConnection::ScheduleSocket()
fails because the new/old socket number is not registered in epoll, so
epoll_ctl() returns ENOENT.  The problem is that it left
`scheduled_flags`, and so subsequent Schedule() calls will use
`EPOLL_CTL_MOD`, which will fail again and again.  Instead, we need to
use `EPOLL_CTL_ADD` to register the new socket.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/806

Closes https://github.com/MusicPlayerDaemon/MPD/issues/756

This flag is output-only.

These flags are output-only.

These flags are output-only.  Using them here is misleading.

The object's state is `IDLE` when OnNfsCallback() gets invoked, so
let's use the start of the method to reset the `state` field.

Fixes assertion failure if the callback fails.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/832

Closes https://github.com/MusicPlayerDaemon/MPD/issues/833

Using CompareStringEx() and FindNLSStringEx().

Implements a missing piece for
https://github.com/MusicPlayerDaemon/MPD/issues/820

LINGUISTIC_IGNORECASE is unimplemented on Wine, but since we don't
have any locale support (yet), and we're using LOCALE_NAME_INVARIANT,
NORM_IGNORECASE should essentially be the same, so why bother.

Reverts commit fb3564fb

LCMapStringEx() doesn't do what I imagined it would do 5 years ago.
D'oh!

Closes https://github.com/MusicPlayerDaemon/MPD/issues/820

Switching == to >= should be safe here since the next if is the opposite.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

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

Found with modernize-raw-string-literal
Signed-off-by: Rosen Penev <rosenp@gmail.com>

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

Unescape the base path and the path coming from the server (href) to fix the
comparison when the server uses different escaped characters.

The outputted name need to be unescaped. Doing that before or after the
HrefToEscapedName() call should not change the current behavior.

If the file name is "Hello & bye", 3 CharacterData events will be sent with the
State::HREF state:
 - "Hello%20"
 - "&"
 - "%20bye"

Reproduced with files hosted on an apache2 DAV server: 2.4.38-3+deb10u3.

Without this, the Pause() call would drop the ring buffers and would
skip a considerable portion of the end of the song.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/824