return an empty set rather than null, to avoid uses having to handle …

…null
wuxiaoxue · Feb 15, 2021 · 7d84a0f · 7d84a0f
1 parent 90fe713
commit 7d84a0f
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/com.ibm.wala.util/src/main/java/com/ibm/wala/util/graph/impl/SparseNumberedEdgeManager.java b/com.ibm.wala.util/src/main/java/com/ibm/wala/util/graph/impl/SparseNumberedEdgeManager.java
@@ -15,6 +15,7 @@
 import com.ibm.wala.util.graph.NumberedNodeManager;
 import com.ibm.wala.util.intset.BasicNaturalRelation;
 import com.ibm.wala.util.intset.BitVector;
+import com.ibm.wala.util.intset.EmptyIntSet;
 import com.ibm.wala.util.intset.IBinaryNaturalRelation;
 import com.ibm.wala.util.intset.IntSet;
 import java.io.Serializable;
@@ -129,7 +130,12 @@ public IntSet getSuccNodeNumbers(T node) throws IllegalArgumentException {
     if (nodeManager.getNumber(node) < 0) {
       throw new IllegalArgumentException("Node not in graph " + node);
     }
-    return successors.getRelated(nodeManager.getNumber(node));
+    IntSet x = successors.getRelated(nodeManager.getNumber(node));
+    if (x == null) {
+      return EmptyIntSet.instance;
+    } else {
+      return x;
+    }
   }
 
   @Override