--- zlib.cpp	2014-02-26 16:16:12.664141000 -0500
+++ zlib_new.cpp	2015-06-05 08:24:10.181878064 -0400
@@ -122,6 +122,8 @@
             static_cast<zlib::uint>(next_out - dest_begin);
         if (length > 0)
             crc_ = crc_imp_ = crc32(crc_imp_, buf, length);
+        else
+            crc_ = crc_imp_ = 0;
     }
     total_in_ = s->total_in;
     total_out_ = s->total_out;