From 4d66ef589058bdfe0ba215107c0fc841a81aa385 Mon Sep 17 00:00:00 2001
From: jjenista <jjenista>
Date: Wed, 4 Mar 2009 00:02:51 +0000
Subject: [PATCH] Return empty sets instead of null

---
 Robust/src/Analysis/CallGraph/CallGraph.java | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Robust/src/Analysis/CallGraph/CallGraph.java b/Robust/src/Analysis/CallGraph/CallGraph.java
index ee148c81..7b011300 100644
--- a/Robust/src/Analysis/CallGraph/CallGraph.java
+++ b/Robust/src/Analysis/CallGraph/CallGraph.java
@@ -37,7 +37,12 @@ public class CallGraph {
   // (MethodDescriptors and/or TaskDescriptors)
   //  that call the given method
   public Set getCallerSet(MethodDescriptor md) {
-    return (Set) mapCallee2CallerSet.get(md);
+    Set s = (Set) mapCallee2CallerSet.get(md);
+    
+    if( s == null ) {
+      return new HashSet();
+    }
+    return s;
   }
 
   // this method returns the set of MethodDescriptors that
@@ -46,7 +51,12 @@ public class CallGraph {
     assert(d instanceof MethodDescriptor) ||
     (d instanceof TaskDescriptor);
 
-    return (Set) mapCaller2CalleeSet.get(d);
+    Set s = (Set) mapCaller2CalleeSet.get(d);
+
+    if( s == null ) {
+      return new HashSet();
+    }
+    return s;
   }
 
   // build a mapping of virtual methods to all
-- 
2.34.1