Backport #29297 by @KN4CK3R
Fixes#29101
Related #29298
Discard all read data to prevent misinterpreting existing data. Some
discard calls were missing in error cases.
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: yp05327 <576951401@qq.com>