added test for this issue

gtsam/nonlinear/tests/testLinearContainerFactor.cpp

@@ -363,6 +363,34 @@ TEST(TestLinearContainerFactor, Rekey) {
   CHECK(assert_equal(linearization_pt_rekeyed.keys()[0], lcf_factor_rekey_ptr->keys()[1]));
 }
 
+/* ************************************************************************* */
+TEST(TestLinearContainerFactor, Rekey2) {
+  // Make an example factor
+  auto nonlinear_factor =
+      boost::make_shared<gtsam::BetweenFactor<gtsam::Point3>>(
+          gtsam::Symbol('x', 0), gtsam::Symbol('l', 0), gtsam::Point3(0, 0, 0),
+          gtsam::noiseModel::Isotropic::Sigma(3, 1));
+
+  // Linearize and create an LCF
+  gtsam::Values linearization_pt;
+  linearization_pt.insert(gtsam::Symbol('x', 0), gtsam::Point3(0, 0, 0));
+  linearization_pt.insert(gtsam::Symbol('l', 0), gtsam::Point3(0, 0, 0));
+
+  LinearContainerFactor lcf_factor(
+      nonlinear_factor->linearize(linearization_pt), linearization_pt);
+
+  // Define a key mapping with only a single key remapped.
+  // This should throw an exception if there is a bug.
+  std::map<gtsam::Key, gtsam::Key> key_map;
+  key_map[gtsam::Symbol('x', 0)] = gtsam::Symbol('x', 4);
+
+  // Cast back to LCF ptr
+  LinearContainerFactor::shared_ptr lcf_factor_rekey_ptr =
+      boost::static_pointer_cast<LinearContainerFactor>(
+          lcf_factor.rekey(key_map));
+  CHECK(lcf_factor_rekey_ptr);
+}
+
 /* ************************************************************************* */
 int main() { TestResult tr; return TestRegistry::runAllTests(tr); }
 /* ************************************************************************* */