Avoid invoking callbacks of a deleted object

diff --git a/source/io/zlibcompressed.h b/source/io/zlibcompressed.h
index feb21c635d406ea567708119fd2c9d467f697f0c..fa7a15315ccb09a7a44a1671e85d26f3ea5b3bc6 100644 (file)
--- a/source/io/zlibcompressed.h
+++ b/source/io/zlibcompressed.h
@@ -3,6 +3,7 @@
 
 #include <stdexcept>
 #include <string>
+#include <sigc++/trackable.h>
 #include "base.h"
 
 namespace Msp {
@@ -27,7 +28,7 @@ operates on top of another I/O object.
 To ensure proper termination of the compressed data stream, the ZlibCompressed
 object must be destroyed before the underlying object is closed.
 */
-class ZlibCompressed: public Base
+class ZlibCompressed: public Base, public sigc::trackable
 {
 private:
        struct Private;