Deadlock in InputUpdateMeta
In the function InputUpdateMeta, if psz_arturl = 'attachment://' then there will be a deadlock on p_item->lock. This is because the call to input_ExtractAttachmentAndCacheArt will indirectly lock p_item.
To reproduce this, simply use automatic download of art cover, play a song and double-click on it (ie. play, stop and play).
LibVLC fatal error locking mutex (35) in thread 3027622800 at ../../src/misc/threads.c:355 in vlc_mutex_lock
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb80252d9]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb802537b]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1(vlc_mutex_lock+0x4a)[0xb80256aa]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1(input_item_IsArtFetched+0x2b)[0xb7fc735b]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb7fe9755]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb7fe5012]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb7fe6e66]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb7fe967a]
/home/videolan/git/vlc/build-master/src/.libs/libvlccore.so.1[0xb8024cc8]
/lib/libpthread.so.0[0xb7f0b155]
/lib/libc.so.6(clone+0x5e)[0xb7e64a5e]
Error message: Resource deadlock avoided