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>

From libavformat/mov.c.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1173

This mapping was added 11 years ago in commit 766b9fd4, but FFmpeg
doesn't appear to support it.

These were added 11 years ago in commit 766b9fd4, but I cannot find
any evidence in the FFmpeg repository that these names were ever
supported.  This commit adds the tags as they are currently present in
libavformat/mov.c.

Upcoming release of game-music-emu will support it, details here: https://bitbucket.org/mpyne/game-music-emu/pull-requests/23/rsn-support

Replaces the static Duplicate() method.

To make things simpler, AllocatedString is now a non-template class.

Regression by commit a22d1c88

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1097