ffmpeg from current git master no longer exposes
av_malloc() nor av_free() through other included
headers. directly include libavutil/mem.h to fix
compilation with (as-yet-unreleased) ffmpeg.

This part of the AVIOContext API is not documented :-(

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1448

Don't return early from ScanOpusTags() if only
TagHandler::WantPicture() is set.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1413

Fixes MixRamp failures when a MP3 file has two ID3 tags, one of them
without MixRamp.

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

SonarLint reports the latter to be better:

std::scoped_lock basically provides the same feature as std::lock_guard,
but is more generic: It can lock several mutexes at the same time, with a
deadlock prevention mechanism (see {rule:cpp:S5524}). The equivalent code
to perform simultaneous locking with std::lock_guard is significantly more
complex. Therefore, it is simpler to use std::scoped_lock all the time,
even when locking only one mutex (there will be no performance impact).
Signed-off-by: Rosen Penev <rosenp@gmail.com>

C arrays can be used with make_unique in C++17.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

For libavcodec 59 support.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1333

Unlike GetFilenameSuffix(), uri_get_suffix() removes the query string
first, which breaks file names with question marks in the name.
Therefore, uri_get_suffix() shall only be applied to remote URIs.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1316

The wrong variable was used.  This has been broken by commit
4eeea640 seven years ago - and nobody as noticed, d'oh!

Fixes crash bug.

make_pair is an old C++98 function that can be replaced by modern
shorter constructs.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

These should be equivalent anyway.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

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

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

Found with cppcoreguidelines-avoid-non-const-global-variables
Signed-off-by: Rosen Penev <rosenp@gmail.com>

If UpdateStreamTag() gets called while an initial seek is pending, the
result will never be submitted to a MusicChunk.  By avoiding the
UpdateStreamTag() call in that case (by moving UpdateStreamTag() to
after the PrepareInitialSeek() check), the song_tag is preserved until
UpdateStreamTag() is called again from SubmitData().

This fixes missing tags in the "httpd" output.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1137

av_demuxer_iterate() was added in libavformat 58.9.100.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1178

Found with cppcoreguidelines-special-member-functions
Signed-off-by: Rosen Penev <rosenp@gmail.com>