pub fn get_return_data() -> Option<ReturnData>Expand description
Read return data from the most recent CPI.
The 1 KiB snapshot buffer is not zero-filled before the syscall, the
syscall initializes exactly the reported prefix, and None is returned
before any read when the runtime reports zero bytes. This is the bug class
behind Quasar #238/#234 (an assume_init over a buffer the syscall never
wrote, exposing uninitialized stack bytes as return data); Hopper’s shape
is immune because uninitialized bytes can never escape: empty return data
short-circuits to None, and every accessor reads only the
syscall-initialized data_len prefix.