Panic: index out of bounds: the len is 0 but the index is 0

[joerg-krause]

Running latest librespot sometimes crash when connecting to the device with the official Spotify desktop client (Spotify version 1.0.32.96.g3c8a06e6, Copyright (c) 2016, Spotify Ltd).

[joerg@nzxt librespot]$ RUST_BACKTRACE=1 target/release/librespot -n Desktop --backend pulseaudio
INFO:librespot::main_helper: librespot 5388565 (2016-07-22). Built on 2016-07-31.
INFO:librespot::main_helper: No username provided and no stored credentials, starting discovery ...
WARN:mdns::fsm: couldn't parse packet from V4(192.168.178.46:5353): class 32769 is invalid
DEBUG:librespot::authentication::discovery: Get "/?action=getInfo" {"action": "getInfo"}
DEBUG:librespot::authentication::discovery: Get "/?action=getInfo" {"action": "getInfo"}
DEBUG:librespot::authentication::discovery: Post "/" {"action": "addUser", "blob": "9DR+aUgAXTrSb40qFz/aoVHgNSi41dvNeNomXXW8y0ki2Y6HvsERCANa4AnzxYR0HpZIxoUBibGJUPMIeslXyH6c8sYZM2N7UZFfRG3lmHgIA4ohP8kkZzW8DW9ots1a/OgD9w==", "clientKey": "AUpe7UCv5+mtcQ4hzVytyV2WXGv2zhdJLB64ATS8vst81MwuuZvYejDbqAm7QD66y16jWxGqWmK9MO6MBgvH++3HJyPbJxsqc4w0z5uQKiQlSmbL8hMW3tBkfw7t1v64", "deviceId": "2b2d707a6f6c93c06f97867d5752c01cbd314ce0", "deviceName": "nzxt", "loginId": "b8708f103510272e0b4c09bc7a83e824", "userName": "joerg-krause"}
INFO:librespot::session: Connecting to AP lon3-accesspoint-a6.ap.spotify.com:443
INFO:librespot::session: Authenticated !
DEBUG:librespot::audio_backend::pulseaudio: Using PulseAudio sink
DEBUG:librespot::spirc: kMessageTypeHello "Desktop" 532c67fe1b5afae15d2d08fba7a78de0f63cc4b5 1 1469969488891
DEBUG:librespot::spirc: kMessageTypeNotify "nzxt" 2b2d707a6f6c93c06f97867d5752c01cbd314ce0 1 0
DEBUG:librespot::spirc: kMessageTypeLoad "nzxt" 2b2d707a6f6c93c06f97867d5752c01cbd314ce0 2 0
thread '<unnamed>' panicked at 'index out of bounds: the len is 0 but the index is 0', ../src/libcollections/vec.rs:1246
stack backtrace:
   1:     0x55ba690d9c6f - std::sys::backtrace::tracing::imp::write::h29f5fdb9fc0a7395
   2:     0x55ba690de80b - std::panicking::default_hook::_{{closure}}::h2cc84f0378700526
   3:     0x55ba690dd9f5 - std::panicking::default_hook::hbbe7fa36a995aca0
   4:     0x55ba690ddffe - std::panicking::rust_panic_with_hook::h105c3d42fcd2fb5e
   5:     0x55ba690dde61 - std::panicking::begin_panic::hbf62ea4a5ff3f9de
   6:     0x55ba690ddd8a - std::panicking::begin_panic_fmt::h20f5943904e5791d
   7:     0x55ba690ddcfe - rust_begin_unwind
   8:     0x55ba69118b4f - core::panicking::panic_fmt::h19323e466869c656
   9:     0x55ba69118af2 - core::panicking::panic_bounds_check::ha883fe1527ce6884
  10:     0x55ba68e23b1d - librespot::spirc::SpircManager::run::h915a765a6c3ffa25
  11:     0x55ba68d4e12b - std::panicking::try::call::hdc8e35d6c115351f
  12:     0x55ba690e6396 - __rust_maybe_catch_panic
  13:     0x55ba68d52e07 - _<F as alloc..boxed..FnBox<A>>::call_box::h85d6926563366f2d
  14:     0x55ba690dc544 - std::sys::thread::Thread::new::thread_start::h8f3bd45211e9f5ea
  15:     0x7f2d1c555483 - start_thread
  16:     0x7f2d1cd866dc - clone
  17:                0x0 - <unknown>
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: RecvError', ../src/libcore/result.rs:788
stack backtrace:
   1:     0x55ba690d9c6f - std::sys::backtrace::tracing::imp::write::h29f5fdb9fc0a7395
   2:     0x55ba690de80b - std::panicking::default_hook::_{{closure}}::h2cc84f0378700526
   3:     0x55ba690dd9f5 - std::panicking::default_hook::hbbe7fa36a995aca0
   4:     0x55ba690ddffe - std::panicking::rust_panic_with_hook::h105c3d42fcd2fb5e
   5:     0x55ba690dde61 - std::panicking::begin_panic::hbf62ea4a5ff3f9de
   6:     0x55ba690ddd8a - std::panicking::begin_panic_fmt::h20f5943904e5791d
   7:     0x55ba690ddcfe - rust_begin_unwind
   8:     0x55ba69118b4f - core::panicking::panic_fmt::h19323e466869c656
   9:     0x55ba68da9e7d - core::result::unwrap_failed::h9d665ebb0f2c6724
  10:     0x55ba68e0fddf - librespot::player::PlayerInternal::run::h0b3e74fd404db001
  11:     0x55ba68d8a2c9 - std::panicking::try::call::h313344cf7abfc55c
  12:     0x55ba690e6396 - __rust_maybe_catch_panic
  13:     0x55ba68dbe2c5 - _<F as alloc..boxed..FnBox<A>>::call_box::hb87e9d8ded216cda
  14:     0x55ba690dc544 - std::sys::thread::Thread::new::thread_start::h8f3bd45211e9f5ea
  15:     0x7f2d1c555483 - start_thread
  16:     0x7f2d1cd866dc - clone
  17:                0x0 - <unknown>
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', ../src/libcore/result.rs:788
stack backtrace:
   1:     0x55ba690d9c6f - std::sys::backtrace::tracing::imp::write::h29f5fdb9fc0a7395
   2:     0x55ba690de80b - std::panicking::default_hook::_{{closure}}::h2cc84f0378700526
   3:     0x55ba690dd9f5 - std::panicking::default_hook::hbbe7fa36a995aca0
   4:     0x55ba690ddffe - std::panicking::rust_panic_with_hook::h105c3d42fcd2fb5e
   5:     0x55ba690dde61 - std::panicking::begin_panic::hbf62ea4a5ff3f9de
   6:     0x55ba690ddd8a - std::panicking::begin_panic_fmt::h20f5943904e5791d
   7:     0x55ba690ddcfe - rust_begin_unwind
   8:     0x55ba69118b4f - core::panicking::panic_fmt::h19323e466869c656
   9:     0x55ba68da9fc4 - core::result::unwrap_failed::hafef74ad5c6462b9
  10:     0x55ba68e05faa - librespot::mercury::MercuryManager::complete_request::h6be47c826ea1ea33
  11:     0x55ba68e07332 - _<librespot..mercury..MercuryManager as librespot..session..PacketHandler>::handle::hd64808e03aeb80de
  12:     0x55ba68e1add9 - librespot::session::Session::poll::ha7c2b664c9f26a0d
  13:     0x55ba68d56a17 - librespot::main::h4c8ffcc1bb2b23f0
  14:     0x55ba690ddc78 - std::panicking::try::call::h5df3ac2979db3c90
  15:     0x55ba690e6396 - __rust_maybe_catch_panic
  16:     0x55ba690dd06e - std::rt::lang_start::hfe9ab243c60ffb9b
  17:     0x7f2d1ccbf740 - __libc_start_main
  18:     0x55ba68d4bde8 - _start
  19:                0x0 - <unknown>

[plietar]

Probably a duplicate of #71
Does it happen when you select the device but no songs are active in the client ?

This is cause by this line :
https://github.com/plietar/librespot/blob/master/src/spirc.rs#L214

The code should take into account the case where an empty list of tracks is received

[joerg-krause]

Does it happen when you select the device but no songs are active in the client ?

Yes, it happens if the queue is empty. If I add songs to the queue before I select the device running librespot it works.

As it looks like this in a duplicate of #71 I'll close this for now.