merged a fix in trunk

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/jinmei-dnsrdata2@776 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/dns/cpp/rdata/generic/rrsig_46.cc

@@ -124,7 +124,7 @@ RRSIG::operator=(const RRSIG& source)
         return (*this);
     }
 
-    RRSIGImpl* newimpl = new RRSIGImpl(*impl_);
+    RRSIGImpl* newimpl = new RRSIGImpl(*source.impl_);
     delete impl_;
     impl_ = newimpl;