From bb6cf7c00bcc55cd55fd28f86ce6add355badc52 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@bnl.gov>
Date: Tue, 15 Feb 2011 11:39:38 -0500
Subject: [PATCH] avoid method resolution problem from diamond inheritance

Serializable -> SerializableArray
Serializable -> PVField
SerializableArray -> PVArray
PVField -> PVArray

Thus for PVArray the members of SerializeSerializable are reachable
by two paths.  This means that The vtable for PVArray has two seperate
entries for serialize.

Correct resolution is to use virtual inheritance to avoid the
ambiguity.
---
 pvDataApp/misc/serialize.h | 2 +-
 pvDataApp/pv/pvData.h      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pvDataApp/misc/serialize.h b/pvDataApp/misc/serialize.h
index effc763..7fa7559 100644
--- a/pvDataApp/misc/serialize.h
+++ b/pvDataApp/misc/serialize.h
@@ -44,7 +44,7 @@ namespace epics { namespace pvData {
     };
 
 
-    class SerializableArray : public Serializable {
+    class SerializableArray : virtual public Serializable {
     public:
         virtual void serialize(ByteBuffer *buffer,
             SerializableControl *flusher, int offset, int count) = 0;
diff --git a/pvDataApp/pv/pvData.h b/pvDataApp/pv/pvData.h
index 22bade9..639cbc8 100644
--- a/pvDataApp/pv/pvData.h
+++ b/pvDataApp/pv/pvData.h
@@ -58,7 +58,7 @@ public:
 
 class PVField
 : public Requester,
-  public Serializable,
+  virtual public Serializable,
   private NoDefaultMethods
 {
 public: