fixes JASSIST-256, adding an annotation to a class doesn't work on reflection

Readme.html

@@ -283,7 +283,7 @@ see javassist.Dump.
 
 <p>-version 3.21
 <ul>
-<li>JIRA JASSIST-244, 245, 248, 255
+<li>JIRA JASSIST-244, 245, 248, 255, 256, 259.
 </ul>
 </p>
 

src/main/javassist/bytecode/annotation/Annotation.java

@@ -78,7 +78,7 @@ public class Annotation {
      * Constructs an annotation including no members.  A member can be
      * later added to the created annotation by <code>addMemberValue()</code>. 
      *
-     * @param typeName  the name of the annotation interface type.
+     * @param typeName  the fully-qualified name of the annotation interface type.
      * @param cp        the constant pool table.
      *
      * @see #addMemberValue(String, MemberValue)

src/main/javassist/bytecode/annotation/ArrayMemberValue.java

@@ -130,7 +130,7 @@ public class ArrayMemberValue extends MemberValue {
      * Writes the value.
      */
     public void write(AnnotationsWriter writer) throws IOException {
-        int num = values.length;
+        int num = values == null ? 0 : values.length;
         writer.arrayValue(num);
         for (int i = 0; i < num; ++i)
             values[i].write(writer);

src/test/javassist/JvstTest5.java

@@ -3,7 +3,9 @@ package javassist;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.TypeVariable;
 
+import javassist.bytecode.AnnotationsAttribute;
 import javassist.bytecode.ClassFile;
+import javassist.bytecode.ConstPool;
 import javassist.bytecode.InnerClassesAttribute;
 
 public class JvstTest5 extends JvstTestRoot {
@@ -142,4 +144,28 @@ public class JvstTest5 extends JvstTestRoot {
         for (CtMethod method : c.getDeclaredMethods())
             method.insertAfter(code);
     }
+
+    public void testJIRA256() throws Exception {
+        // CtClass ec = sloader.get("test5.Entity");
+
+        CtClass cc = sloader.makeClass("test5.JIRA256");
+        ClassFile ccFile = cc.getClassFile();
+        ConstPool constpool = ccFile.getConstPool();
+         
+        AnnotationsAttribute attr = new AnnotationsAttribute(constpool, AnnotationsAttribute.visibleTag);
+        javassist.bytecode.annotation.Annotation entityAnno
+            = new javassist.bytecode.annotation.Annotation("test5.Entity", constpool);
+            // = new javassist.bytecode.annotation.Annotation(constpool, ec);
+
+        entityAnno.addMemberValue("value", new javassist.bytecode.annotation.ArrayMemberValue(constpool));
+        attr.addAnnotation(entityAnno);
+        ccFile.addAttribute(attr);
+
+        cc.writeFile();
+        Object o = make(cc.getName());
+        assertTrue(o.getClass().getName().equals("test5.JIRA256"));
+
+        java.lang.annotation.Annotation[] annotations = o.getClass().getDeclaredAnnotations();
+        assertEquals(1, annotations.length); 
+    }
 }

src/test/test5/Entity.java

@@ -0,0 +1,9 @@
+package test5;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Entity {
+    int[] value();
+}