File protobuf-return-no-nonvoid.patch of Package protobuf

Index: protobuf-2.6.1/src/google/protobuf/extension_set.cc
===================================================================
--- protobuf-2.6.1.orig/src/google/protobuf/extension_set.cc
+++ protobuf-2.6.1/src/google/protobuf/extension_set.cc
@@ -71,6 +71,7 @@ inline bool is_packable(WireFormatLite::
     // Do not add a default statement. Let the compiler complain when someone
     // adds a new wire type.
   }
+  return true;
 }
 
 // Registry stuff.