Bug 81603 [Import/Export] tar import/export does not preserve file permissions
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/TarInputStream.java
while(nextEntry > 0) {
			long ret = in.skip(nextEntry);
			if(ret < 0) {
				throw new IOException("early end of stream"); 
			}
			nextEntry -= ret;
			bytesread += ret;
		}
		int bytestoread = 512;
		while(bytestoread > 0) {
			int ret = super.read(header, 512 - bytestoread, bytestoread);
			if( ret < 0 ) {
				throw new IOException("early end of stream"); 
			}
			bytestoread -= ret;
			bytesread += ret;
		}
		
		if(headerChecksum(header) == 0) {
			
			if(filepos > 0) {
				return null;
			}
			
			
			throw new TarException("not in tar format"); 
		}
		
		
		if(!isValidTarHeader(header)) {