fix minor bug in HybridConditional and test its serialization

gtsam/hybrid/HybridConditional.cpp

@@ -116,7 +116,6 @@ bool HybridConditional::equals(const HybridFactor &other, double tol) const {
     auto other = e->asDiscrete();
     return other != nullptr && dc->equals(*other, tol);
   }
-  return inner_->equals(*(e->inner_), tol);
 
   return inner_ ? (e->inner_ ? inner_->equals(*(e->inner_), tol) : false)
                 : !(e->inner_);

gtsam/hybrid/tests/testSerializationHybrid.cpp

@@ -19,6 +19,7 @@
 #include <gtsam/base/serializationTestHelpers.h>
 #include <gtsam/hybrid/GaussianMixture.h>
 #include <gtsam/hybrid/GaussianMixtureFactor.h>
+#include <gtsam/hybrid/HybridConditional.h>
 #include <gtsam/hybrid/HybridDiscreteFactor.h>
 #include <gtsam/hybrid/HybridGaussianFactor.h>
 #include <gtsam/inference/Symbol.h>
@@ -105,6 +106,20 @@ TEST(HybridSerialization, GaussianMixtureFactor) {
   EXPECT(equalsBinary<GaussianMixtureFactor>(factor));
 }
 
+/* ****************************************************************************/
+// Test HybridConditional serialization.
+TEST(HybridSerialization, HybridConditional) {
+  const DiscreteKey mode(M(0), 2);
+  Matrix1 I = Matrix1::Identity();
+  const auto conditional = boost::make_shared<GaussianConditional>(
+      GaussianConditional::FromMeanAndStddev(Z(0), I, X(0), Vector1(0), 0.5));
+  const HybridConditional hc(conditional);
+
+  EXPECT(equalsObj<HybridConditional>(hc));
+  EXPECT(equalsXML<HybridConditional>(hc));
+  EXPECT(equalsBinary<HybridConditional>(hc));
+}
+
 /* ****************************************************************************/
 // Test GaussianMixture serialization.
 TEST(HybridSerialization, GaussianMixture) {