diff -dur 1/bzip2.cpp 2/bzip2.cpp
--- 1/bzip2.cpp	2008-03-23 03:53:35.000000000 +0600
+++ 2/bzip2.cpp	2009-08-17 22:27:56.000000000 +0700
@@ -100,6 +100,7 @@
 
 void bzip2_base::end(bool compress)
 {
+    if (!ready_) return;
     ready_ = false;
     bz_stream* s = static_cast<bz_stream*>(stream_);
     bzip2_error::check(