From 2ac1473a84f1785cefe1a12008cd370548e6cd5c Mon Sep 17 00:00:00 2001
From: Richard Roberts <richard.jw.roberts@gmail.com>
Date: Mon, 9 Apr 2012 03:02:11 +0000
Subject: [PATCH] Fixed iSAM2 deep copy of empty tree

---
 gtsam/inference/BayesTree-inl.h | 7 +++++++
 gtsam/inference/BayesTree.h     | 4 +---
 tests/testGaussianISAM2.cpp     | 5 +++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/gtsam/inference/BayesTree-inl.h b/gtsam/inference/BayesTree-inl.h
index 6881e9a69..95b070739 100644
--- a/gtsam/inference/BayesTree-inl.h
+++ b/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(
diff --git a/gtsam/inference/BayesTree.h b/gtsam/inference/BayesTree.h
index 3df697a48..aba7181ff 100644
--- a/gtsam/inference/BayesTree.h
+++ b/gtsam/inference/BayesTree.h
@@ -283,9 +283,7 @@ namespace gtsam {
   private:
 
     /** deep copy to another tree */
-		void cloneTo(This& newTree) const {
-		  cloneTo(newTree, root(), sharedClique());
-		}
+		void cloneTo(This& newTree) const;
 
 		/** deep copy to another tree */
 		void cloneTo(This& newTree, const sharedClique& subtree, const sharedClique& parent) const;
diff --git a/tests/testGaussianISAM2.cpp b/tests/testGaussianISAM2.cpp
index 5ff24070c..9b1bd546f 100644
--- a/tests/testGaussianISAM2.cpp
+++ b/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));
 }
 
 /* ************************************************************************* */