Binary plist object tables may list one object offset more than once;
plistlib reads each entry independently. The scalar scanner marked any
repeated offset as incomplete metadata, which made the number projection
drop every exact decimal in the archive. A keyed archive whose entries
10 and 11 share an Int64 9007199254740993 reported both as observed
9007199254740992 and rounded an unrelated 2^60+3 sibling, with only the
generic incomplete-metadata caveat.
A repeated valid offset carries the same source facts as its first
visit, so observe it once and continue. Offsets that fail to parse still
mark metadata incomplete. Shared 16-byte integers and dates are rewritten
once in the decoder copy, which every entry then reads; the overlap plan
already treats one shared offset as one span. Keyed archives and
Interface Builder decoding share this scanner.
Shreyash Patange