Crash on r_restart / r_toggle_fullscreen about quetoo HOT 7 CLOSED

r_fullscreen will be changed on r_restart.
Video initialization...
  Trying 1913x1074..
  Setting up OpenGL context..
  Renderer:   NVIDIA GeForce GTX 1080 Ti/PCIe/SSE2
  Vendor:     NVIDIA Corporation
  Version:    3.3.0 NVIDIA 470.94
Video initialized 1920x1080 (1920x1080) fullscreen
r_fullscreen will be changed on r_restart.
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
quetoo: s_mix.c:162: S_MixChannels: Assertion `ch->play.sample->buffer' failed.
--Type <RET> for more, q to quit, c to continue without paging--

Thread 1 "quetoo" received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:49
49	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:49
#1  0x00007ffff7745536 in __GI_abort () at abort.c:79
#2  0x00007ffff774541f in __assert_fail_base (
    fmt=0x7ffff78ab978 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
    assertion=0x5555555c0135 "ch->play.sample->buffer", file=0x5555555c012d "s_mix.c",
    line=162, function=<optimized out>) at assert.c:92
#3  0x00007ffff7754212 in __GI___assert_fail (
    assertion=assertion@entry=0x5555555c0135 "ch->play.sample->buffer",
    file=file@entry=0x5555555c012d "s_mix.c", line=line@entry=162,
    function=function@entry=0x5555555c0198 <__PRETTY_FUNCTION__.3> "S_MixChannels")
    at assert.c:101
#4  0x000055555558cb8f in S_MixChannels (stage=stage@entry=0x5555555dcc40 <cl_stage>)
    at s_mix.c:162
#5  0x000055555558b8e0 in S_RenderStage (stage=stage@entry=0x5555555dcc40 <cl_stage>)
    at s_main.c:237
#6  0x0000555555560d0e in Cl_Frame (msec=msec@entry=1) at cl_main.c:666
#7  0x000055555555f884 in Frame (msec=1) at main.c:410
#8  main (argc=1, argv=0x7fffffffe778) at main.c:459
(gdb) quit
A debugging session is active.

	Inferior 1 [process 129100] will be killed.

if (!ch->play.sample->buffer) {
  Com_Print("entity %d\n", ch->play.entity);
  Com_Print("media %s\n", ch->play.sample->media.name);
}

assert(ch->play.sample->buffer);

entity 1
media #players/common/step_default_2
quetoo: s_mix.c:167: S_MixChannels: Assertion `ch->play.sample->buffer' failed.
Sys_Signal: Received signal 6