CVE-2024-10573: Out-of-bounds write during PCM decoding of crafted streams
could lead to heap corruption and potential arbitrary code execution; decode
the MPEG header into a temporary copy that is only applied to the live
handle after the frame body is validated (upstream svn-r5442, main fix), and
gate decodetheframe() behind a FRAMEDECODERLIVE state bit so it cannot
run with stale state when decode_update() failed (upstream svn-r4991 plus
the bug-324 precedence fix from 1.29.2, follow-up safeguard).