From 0341eeebea854bec13429540b3debb0c030dd253 Mon Sep 17 00:00:00 2001
From: ngocpq <phungquangngoc@gmail.com>
Date: Wed, 12 Dec 2018 17:55:43 +0900
Subject: [PATCH] [fix-bug]: checking attrs is not null in method
 StackFrame:replaceLocalAttr( ) (#166)

* fix-bug in StackFrame.replaceLocalAttr: attrs is null

* add test-case
---
 src/main/gov/nasa/jpf/vm/StackFrame.java      |  2 +-
 src/tests/gov/nasa/jpf/vm/StackFrameTest.java | 57 +++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 src/tests/gov/nasa/jpf/vm/StackFrameTest.java

diff --git a/src/main/gov/nasa/jpf/vm/StackFrame.java b/src/main/gov/nasa/jpf/vm/StackFrame.java
index 0c642af..59c29ae 100644
--- a/src/main/gov/nasa/jpf/vm/StackFrame.java
+++ b/src/main/gov/nasa/jpf/vm/StackFrame.java
@@ -825,7 +825,7 @@ public abstract class StackFrame implements Cloneable {
 
   public void replaceLocalAttr (int index, Object oldAttr, Object newAttr){
     assert index < stackBase && oldAttr != null && newAttr != null;
-    if (attrs == null){
+    if (attrs != null){
       attrs[index] = ObjectList.replace(attrs[index], oldAttr, newAttr);    
     }
   }
diff --git a/src/tests/gov/nasa/jpf/vm/StackFrameTest.java b/src/tests/gov/nasa/jpf/vm/StackFrameTest.java
new file mode 100644
index 0000000..41a020d
--- /dev/null
+++ b/src/tests/gov/nasa/jpf/vm/StackFrameTest.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is licensed under the
+ * Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0. 
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+
+package gov.nasa.jpf.vm;
+
+import gov.nasa.jpf.jvm.JVMStackFrame;
+import gov.nasa.jpf.util.test.TestJPF;
+import java.lang.reflect.Modifier;
+
+import org.junit.Test;
+
+/**
+ * unit test for StackFrame operations
+ */
+public class StackFrameTest extends TestJPF {
+
+	@Test
+	public void testReplaceLocalAttr() {
+
+		MethodInfo mInfo = new MethodInfo("[methodName]", "()V", Modifier.PUBLIC, 2, 10);
+		JVMStackFrame frame = new JVMStackFrame(mInfo);
+		// Initialize local values and the stack frame
+		frame.push(1);
+
+		String obj1 = "Attribute1";
+		Class<?> attrType = obj1.getClass();
+		frame.addLocalAttr(0, obj1);
+
+		final Object oldAttr = frame.getLocalAttr(0, attrType);
+		assertTrue(oldAttr != null && oldAttr == obj1);
+
+		String obj2 = "Attribute2";
+		frame.replaceLocalAttr(0, oldAttr, obj2);
+
+		final Object newAttr = frame.getLocalAttr(0, attrType);
+		assertTrue(newAttr != null && newAttr == obj2);
+	}
+	
+	public static void main(String[] args) {
+		runTestsOfThisClass(null);
+	}
+}
-- 
2.34.1