Fixes out of array access
Fixes: 24d05e8b84676799c735c9e27d97895e/asan_heap-oob_1b70f6a_2955_7c3652a7f370f9f3ef40642bc2c99bb2.bit
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 93f30f825c)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
tags/n2.8.2