From d4920687047dbf8b9fdbc353d993ca9fc85faf4e Mon Sep 17 00:00:00 2001
From: Varun Agrawal <varagrawal@gmail.com>
Date: Fri, 11 Apr 2025 16:46:11 -0400
Subject: [PATCH] first restrict before checking numer of keys

---
 gtsam/hybrid/HybridNonlinearFactorGraph.cpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/gtsam/hybrid/HybridNonlinearFactorGraph.cpp b/gtsam/hybrid/HybridNonlinearFactorGraph.cpp
index 4f8cf45ee..6ab28ccb4 100644
--- a/gtsam/hybrid/HybridNonlinearFactorGraph.cpp
+++ b/gtsam/hybrid/HybridNonlinearFactorGraph.cpp
@@ -23,7 +23,6 @@
 #include <gtsam/hybrid/HybridNonlinearFactor.h>
 #include <gtsam/hybrid/HybridNonlinearFactorGraph.h>
 #include <gtsam/nonlinear/NonlinearFactor.h>
-
 namespace gtsam {
 
 /* ************************************************************************* */
@@ -237,10 +236,11 @@ HybridNonlinearFactorGraph HybridNonlinearFactorGraph::restrict(
     if (auto hf = dynamic_pointer_cast<HybridFactor>(f)) {
       result.push_back(hf->restrict(discreteValues));
     } else if (auto df = dynamic_pointer_cast<DiscreteFactor>(f)) {
-      // In the case where all the values have been selected, we ignore the
-      // factor since it doesn't add any information
-      if (df->discreteKeys().size() > 0) {
-        result.push_back(df->restrict(discreteValues));
+      auto restricted_df = df->restrict(discreteValues);
+      // In the case where all the discrete values have been selected,
+      // we ignore the factor since it doesn't add any information
+      if (restricted_df->discreteKeys().size() > 0) {
+        result.push_back(restricted_df);
       }
     } else {
       result.push_back(f);  // Everything else is just added as is