internal static void HandlePK00Prefix(Stream s)
{
// in some cases, the zip file begins with "PK00". This is a throwback and is rare,
// but we handle it anyway. We do not change behavior based on it.
uint datum = (uint)SharedUtilities.ReadInt(s);
if (datum != ZipConstants.PackedToRemovableMedia)
{
s.Seek(-4, SeekOrigin.Current); // unread the block
}
}
private static void HandleUnexpectedDataDescriptor(ZipEntry entry)
{
Stream s = entry.ArchiveStream;
// In some cases, the "data descriptor" is present, without a signature, even when
// bit 3 of the BitField is NOT SET. This is the CRC, followed
// by the compressed length and the uncompressed length (4 bytes for each
// of those three elements). Need to check that here.
//
uint datum = (uint)SharedUtilities.ReadInt(s);
if (datum == entry._Crc32)
{
int sz = SharedUtilities.ReadInt(s);
if (sz == entry._CompressedSize)
{
sz = SharedUtilities.ReadInt(s);
if (sz == entry._UncompressedSize)
{
// ignore everything and discard it.
}
else
{
s.Seek(-12, SeekOrigin.Current); // unread the three blocks
}
}
else
{
s.Seek(-8, SeekOrigin.Current); // unread the two blocks
}
}
else
{
s.Seek(-4, SeekOrigin.Current); // unread the block
}
}