fn shortened_at(body: &[u8], descend: bool) -> Option<Vec<u8>>Expand description
signature_shortened, the signatures embedded in the unhashed area
looked into only when descend: one level, never more. An embedded
signature’s own embedded ones stay as they came: Sequoia refuses a
signature embedded in an embedded one, and each level looked into would
take the stack of the thread reading a file from outside (a phone’s
import runs on Qt’s own, about 1 MiB), a crafted one nesting thousands.