Assertion `res <= (int)in->sz' failed in dav1d_decode() src/lib.c

Found with commit acd90b71

Steps to reproduce:

1. run attached testcase with dav1d executable ./dav1d -i testcase.ivf -o out.ivf

testcase.ivf

dav1d: ../src/lib.c:196: int dav1d_decode(Dav1dContext *const, Dav1dData *const, Dav1dPicture *const): Assertion `res <= (int)in->sz' failed.
    #0 0x7f5996d2c427 in gsignal /build/glibc-Cl5G7W/glibc-2.23/signal/../sysdeps/unix/sysv/linux/raise.c:54
    #1 0x7f5996d2e029 in abort /build/glibc-Cl5G7W/glibc-2.23/stdlib/abort.c:89
    #2 0x7f5996d24bd6 in __assert_fail_base /build/glibc-Cl5G7W/glibc-2.23/assert/assert.c:92
    #3 0x7f5996d24c81 in __assert_fail /build/glibc-Cl5G7W/glibc-2.23/assert/assert.c:101
    #4 0x4f672e in dav1d_decode src/lib.c:196:9
    #5 0x4eaa77 in main tools/dav1d.c:108:20
    #6 0x7f5996d1782f in __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/libc-start.c:291
    #7 0x418d38 in _start (dav1d+0x418d38)