Fix bug in CompareMatchingResultSize

include/aidge/graph/Matching.hpp

@@ -197,12 +197,19 @@ private:
 
     struct CompareMatchingResultSize {
         bool operator()(const MatchingResult& lhs, const MatchingResult& rhs) const {
+            // Some matches size could be the same
+            if (lhs.graph->getNodes().size() == rhs.graph->getNodes().size()) {
+                // In this case, use rootNode which is garanteed to be different!
+                return lhs.graph->rootNode() < rhs.graph->rootNode();
+            }
+
             return lhs.graph->getNodes().size() > rhs.graph->getNodes().size();
         }
     };
 };
 
 inline bool operator<(const Aidge::SinglePassGraphMatching::MatchingResult& lhs, const Aidge::SinglePassGraphMatching::MatchingResult& rhs) {
+    // Matches rootNode are garanteed to be different!
     return lhs.graph->rootNode() < rhs.graph->rootNode();
 }
 }  // namespace Aidge