From 6d0705c5dc41031bc3f4a143027dbe09f8d1c48e Mon Sep 17 00:00:00 2001
From: Fan Jiang <prof.fan@foxmail.com>
Date: Sun, 8 Dec 2019 00:50:30 -0500
Subject: [PATCH] Workaround for boost serialization bug for NULL shared_ptrs
 version < 1.66.0

---
 gtsam/linear/JacobianFactor.h | 42 ++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/gtsam/linear/JacobianFactor.h b/gtsam/linear/JacobianFactor.h
index c8d77c554..53ce4b9ca 100644
--- a/gtsam/linear/JacobianFactor.h
+++ b/gtsam/linear/JacobianFactor.h
@@ -25,6 +25,8 @@
 #include <gtsam/inference/VariableSlots.h>
 
 #include <boost/make_shared.hpp>
+#include <boost/serialization/version.hpp>
+#include <boost/serialization/split_member.hpp>
 
 namespace gtsam {
 
@@ -406,13 +408,41 @@ namespace gtsam {
     /** Serialization function */
     friend class boost::serialization::access;
     template<class ARCHIVE>
-    void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
-      ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
-      ar & BOOST_SERIALIZATION_NVP(Ab_);
-      ar & BOOST_SERIALIZATION_NVP(model_);
+    void save(ARCHIVE & ar, const unsigned int version) const {
+      // TODO(fan): This is a hack for Boost < 1.66
+      // We really need to introduce proper versioning in the archives
+      // As otherwise this will not read objects serialized by older
+      // versions of GTSAM
+      ar << BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+      ar << BOOST_SERIALIZATION_NVP(Ab_);
+      bool model_null = false;
+      if(model_.get() == nullptr) {
+        model_null = true;
+        ar << boost::serialization::make_nvp("model_null", model_null);
+      } else {
+        ar << boost::serialization::make_nvp("model_null", model_null);
+        ar << BOOST_SERIALIZATION_NVP(model_);
+      }
     }
-  }; // JacobianFactor
 
+    template<class ARCHIVE>
+    void load(ARCHIVE & ar, const unsigned int version) {
+      // invoke serialization of the base class
+      ar >> BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+      ar >> BOOST_SERIALIZATION_NVP(Ab_);
+      if (version < 1) {
+        ar >> BOOST_SERIALIZATION_NVP(model_);
+      } else {
+        bool model_null;
+        ar >> BOOST_SERIALIZATION_NVP(model_null);
+        if (!model_null) {
+          ar >> BOOST_SERIALIZATION_NVP(model_);
+        }
+      }
+    }
+
+    BOOST_SERIALIZATION_SPLIT_MEMBER()
+  }; // JacobianFactor
 /// traits
 template<>
 struct traits<JacobianFactor> : public Testable<JacobianFactor> {
@@ -420,6 +450,8 @@ struct traits<JacobianFactor> : public Testable<JacobianFactor> {
 
 } // \ namespace gtsam
 
+BOOST_CLASS_VERSION(gtsam::JacobianFactor, 1)
+
 #include <gtsam/linear/JacobianFactor-inl.h>