demux/playlist/xspf: crash on empty vlc:id tag
Playing an .xspf
containing <vlc:id></vlc:id>
will crash
due to a null-pointer dereference. See attached sample.
AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7f900c837d45 bp 0x7f8fef408690 sp 0x7f8fef407db0 T4)
[#0](https://code.videolan.org/videolan/vlc/-/issues/0) 0x7f900c837d44 in __GI_____strtoll_l_internal (/usr/lib/libc.so.6+0x36d44)
[#1](https://code.videolan.org/videolan/vlc/-/issues/1) 0x4311f8 in __interceptor_atoi.part.47 (/home/refp/work/videolan/vlc/git/builds/branches/trunk/asan/bin/vlc-static+0x4311f8)
[#2](https://code.videolan.org/videolan/vlc/-/issues/2) 0x7f9002ed3f87 in parse_extension_node /home/refp/work/videolan/vlc/git/modules/demux/playlist/xspf.c:746:50
[#3](https://code.videolan.org/videolan/vlc/-/issues/3) 0x7f9002ed4d11 in parse_track_node /home/refp/work/videolan/vlc/git/modules/demux/playlist/xspf.c:407:18
[#4](https://code.videolan.org/videolan/vlc/-/issues/4) 0x7f9002ed4361 in parse_tracklist_node /home/refp/work/videolan/vlc/git/modules/demux/playlist/xspf.c:325:17
[#5](https://code.videolan.org/videolan/vlc/-/issues/5) 0x7f9002ed340e in parse_playlist_node /home/refp/work/videolan/vlc/git/modules/demux/playlist/xspf.c:260:18
[#6](https://code.videolan.org/videolan/vlc/-/issues/6) 0x7f9002ed2a9d in Demux /home/refp/work/videolan/vlc/git/modules/demux/playlist/xspf.c:148:13
[#7](https://code.videolan.org/videolan/vlc/-/issues/7) 0x7f900deba288 in MainLoopDemux /home/refp/work/videolan/vlc/git/src/input/input.c:559:17
[#8](https://code.videolan.org/videolan/vlc/-/issues/8) 0x7f900deb7266 in MainLoop /home/refp/work/videolan/vlc/git/src/input/input.c:705:17
[#9](https://code.videolan.org/videolan/vlc/-/issues/9) 0x7f900deb8623 in Preparse /home/refp/work/videolan/vlc/git/src/input/input.c:522:13
[#10](https://code.videolan.org/videolan/vlc/-/issues/10) 0x7f900cfc5453 in start_thread (/usr/lib/libpthread.so.0+0x7453)
[#11](https://code.videolan.org/videolan/vlc/-/issues/11) 0x7f900c8e97de in __GI___clone (/usr/lib/libc.so.6+0xe87de)