From f39bad0d137d56603c050d53b09e15743cfaaab6 Mon Sep 17 00:00:00 2001
From: Stephen Williams <stephen.vincent.williams@gmail.com>
Date: Fri, 3 Aug 2012 19:05:48 +0000
Subject: [PATCH] When erasing cached shortcut conditionals in the Bayes Tree,
 only erase the chains of shortcuts that exist instead of the whole tree.

---
 gtsam/inference/BayesTreeCliqueBase-inl.h | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/gtsam/inference/BayesTreeCliqueBase-inl.h b/gtsam/inference/BayesTreeCliqueBase-inl.h
index f96566536..344f845ac 100644
--- a/gtsam/inference/BayesTreeCliqueBase-inl.h
+++ b/gtsam/inference/BayesTreeCliqueBase-inl.h
@@ -268,12 +268,19 @@ namespace gtsam {
 	/* ************************************************************************* */
 	template<class DERIVED, class CONDITIONAL>
 	void BayesTreeCliqueBase<DERIVED, CONDITIONAL>::deleteCachedShorcuts() {
-		//Delete CachedShortcut for this clique
-		this->resetCachedShortcut();
-		// Recursive call over all child cliques
-		BOOST_FOREACH(derived_ptr& child, children_) {
-			child->deleteCachedShorcuts();
-		}
+
+	  // When a shortcut is requested, all of the shortcuts between it and the
+	  // root are also generated. So, if this clique's cached shortcut is set,
+	  // recursively call over all child cliques. Otherwise, it is unnecessary.
+	  if(cachedShortcut_) {
+	    BOOST_FOREACH(derived_ptr& child, children_) {
+	      child->deleteCachedShorcuts();
+	    }
+
+	    //Delete CachedShortcut for this clique
+	    this->resetCachedShortcut();
+	  }
+
 	}
 
 }