Fix zip64 reader when file size is < 4GB and 32 bit fields are -1

When CopyFrom writes a zipentry, it strips extra fields and generates
data descriptors. When writing data descriptors, it only writes 64 bit
values if the relevant sizes are >4GB. In some cases, the sizes are <4GB
but 32 bit sizes are set to -1. In this situation, CopyFrom will write
incorrect local file header, resulting in a zip file that can't be
parsed by standard zip tools.

Test: Unit Tests
Bug: 161922066
Change-Id: I64319a80647013eaf7693cf8bf5c6120016913a3

third_party/zip/android.go

@@ -43,6 +43,15 @@ func (w *Writer) CopyFrom(orig *File, newName string) error {
 		offset:     uint64(w.cw.count),
 	}
 	w.dir = append(w.dir, h)
+	if !fh.isZip64() {
+		// Some writers will generate 64 bit sizes and set 32 bit fields to
+		// uint32max even if the actual size fits in 32 bit. So we should
+		// make sure CompressedSize contains the correct value in such
+		// cases. With out the two lines below we would be writing invalid(-1)
+		// sizes in such case.
+		fh.CompressedSize = uint32(fh.CompressedSize64)
+		fh.UncompressedSize = uint32(fh.UncompressedSize64)
+	}
 
 	if err := writeHeader(w.cw, fh); err != nil {
 		return err