then you wrote a bad extractor. Scanning forward is against the format. Zipping up a zip file is a perfectly valid thing to do. If the inner zip is stored uncom

then you wrote a bad extractor. Scanning forward is against the format. Zipping up a zip file is a perfectly valid thing to do. If the inner zip is stored uncompressed you'll have 2 headers at the end. If you scan forward you'll fail.