Fixed iSAM2 deep copy of empty tree

gtsam/inference/BayesTree-inl.h

@@ -582,6 +582,13 @@ namespace gtsam {
 	  }
 	}
 
+  /* ************************************************************************* */
+	template<class CONDITIONAL, class CLIQUE>
+	void BayesTree<CONDITIONAL,CLIQUE>::cloneTo(This& newTree) const {
+	  if(root())
+	    cloneTo(newTree, root(), sharedClique());
+	}
+
 	/* ************************************************************************* */
   template<class CONDITIONAL, class CLIQUE>
 	void BayesTree<CONDITIONAL,CLIQUE>::cloneTo(

gtsam/inference/BayesTree.h

@@ -283,9 +283,7 @@ namespace gtsam {
   private:
 
     /** deep copy to another tree */
-		void cloneTo(This& newTree) const {
+		void cloneTo(This& newTree) const;
-		  cloneTo(newTree, root(), sharedClique());
-		}
 
 		/** deep copy to another tree */
 		void cloneTo(This& newTree, const sharedClique& subtree, const sharedClique& parent) const;

tests/testGaussianISAM2.cpp

@@ -898,6 +898,11 @@ TEST(ISAM2, clone) {
 
   CHECK(assert_equal(createSlamlikeISAM2(), clone1));
   CHECK(assert_equal(clone1, temp));
+
+  // Check clone empty
+  ISAM2 isam;
+  clone1 = isam;
+  CHECK(assert_equal(ISAM2(), clone1));
 }
 
 /* ************************************************************************* */