By default, if the parent of a process dies, the process gets SIGHUP
and is supposed to shut down.  This however doesn't work for MPD,
because MPD redefines SIGHUP with a different meaning (like most
daemons do).

To work around this, we configure the kernel to send SIGTERM instead
of SIGHUP.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1706

Fixes a busy loop in BufferingInputStream::RunThreadLocked() because
the method never learns that seeking is ignored, even though the HTTP
stream is already broken and can never be read; nobody cared to check
for errors.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1727

When drop_start_samples and drop_end_samples overlap and are greater
than the actual number of samples, the `num_samples` calculation in
SubmitPCM() could underflow.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1712

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1721

For CURLINFO_CONTENT_LENGTH_DOWNLOAD_T (commit 4efd0a9f).

This compile-time option is not about debug logging, but about
curl_easy_strerror().

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1670

The function spl_valid_name() should verify playlist names and prevent
path traversal, but it failed to do so on Windows, because it forgot
to check for backslashes.

This buggy piece of code was already present when stored playlists
were initially implemented in 2006 by commit 08003904, and
even during the many rounds of code refactoring, nobody ever bothered
to verify it.  D'oh!

(Thanks, Paul Arzelier)

snprintf() does not return the (truncated) length actually written,
but the length that would be needed if the buffer were large enough.
This API usage mistake in FormatLastError() can lead to overflow of
the stack buffer, crashing the process (Windows only).

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1676

If no archive library was found, return from the "plugins" directory
without creating "libarchive_plugins.a".  Empty static libraries are
unsupported on some operating systems such as macOS.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1650

Punycode hooray!

It is not explicitly documented whether snd_pcm_name() is allowed to
return NULL:
https://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#ga5031edc0422df8db1f70af056a12dd77

But apparently this is legal:
https://github.com/alsa-project/alsa-lib/blob/0222f45d11e8b71bf651b985b00fdb0addbf3eed/src/pcm/pcm.c#L2761-L2762

That's ... surprising!

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1645

Fixes compiler warning because formatting unscoped enums is deprecated
since libfmt 9.

Don't require "log_file" setting, for "--no-config" operation.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1600

See also https://github.com/MusicPlayerDaemon/MPD/issues/1061

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1570

This ensures that Partition::OnMixerVolumeChanged() invokes
MixerMemento::InvalidateHardwareVolume(), clearing the cached volume
level.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1526

Eliminate global variables, convert them to MixerMemento fields.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1583

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1529

This PR provides forward and backward compatibility at macos SDK 12.0. At SDK 12.0, API function names were changed essentially replacing
occurrences of the word Master/master with Main/main. This change was test built on two different systems.

1. macos 10.15.7 with Xcode 12.4 and clang 12.0.0 on x86_64
2. macos 12.5 with Xcode 13.4.1 and clang 13.1.6 on arm64 (Apple silicon M1)

It should be noted that on macos 10.15.7 with Xcode 11.2 and clang 11.0, MPD will not build.
The MPD documentation states that clang 11.0 is the minimum requirement,
but clang 11.0 produces compile errors. Apparently the macos version
of clang 11.0 is not fully compliant.

Commit ebae25d1 added that #include, but forgot to wrap it in
"extern C", so the linker tried to look up C++ symbols, causing linker
failure.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1582

Properly deals with iconv, unlike the current solution. have_iconv fails
when libiconv CFLAGS are passed to the compiler. Tested under OpenWrt
with its CONFIG_BUILD_NLS, which adds libiconv include flags.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Closes #1564

Deactivate the stream in Cancel().  This fixes stuttering after a
manual song change by refilling the whole ring buffer before
reactivating the stream.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1354

Clear not only MPD's ring buffer, but also libpipewire's buffers, to
avoid playing some audio from the previous song after a manual song
change.

Fixes part 1 of https://github.com/MusicPlayerDaemon/MPD/issues/1354