From d8ec011d770e1e04ef4f87fba673f3748f363278 Mon Sep 17 00:00:00 2001
From: Dmitry Ovchinnikov <d.ovchinnikow@gmail.com>
Date: Sun, 12 Nov 2017 21:49:07 +0300
Subject: [PATCH] LANG-1371: Fix TypeUtils.parameterize to work correctly with
 narrower-typed varargs array (closes #307)

---
 .../org/apache/commons/lang3/reflect/TypeUtils.java    |  2 +-
 .../apache/commons/lang3/reflect/TypeUtilsTest.java    | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java b/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
index 3a7ac1780..efb630c62 100644
--- a/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
+++ b/src/main/java/org/apache/commons/lang3/reflect/TypeUtils.java
@@ -157,7 +157,7 @@ public class TypeUtils {
         private ParameterizedTypeImpl(final Class<?> raw, final Type useOwner, final Type[] typeArguments) {
             this.raw = raw;
             this.useOwner = useOwner;
-            this.typeArguments = typeArguments.clone();
+            this.typeArguments = Arrays.copyOf(typeArguments, typeArguments.length, Type[].class);
         }
 
         /**
diff --git a/src/test/java/org/apache/commons/lang3/reflect/TypeUtilsTest.java b/src/test/java/org/apache/commons/lang3/reflect/TypeUtilsTest.java
index acdf77c86..a9bb9fab6 100644
--- a/src/test/java/org/apache/commons/lang3/reflect/TypeUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/reflect/TypeUtilsTest.java
@@ -34,6 +34,7 @@ import java.net.URI;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -690,6 +691,15 @@ public class TypeUtilsTest<B> {
         assertEquals("java.lang.Comparable<java.lang.String>", stringComparableType.toString());
     }
 
+    @Test
+    public void testParameterizeNarrowerTypeArray() {
+        final TypeVariable<?>[] variables = ArrayList.class.getTypeParameters();
+        final ParameterizedType parameterizedType = TypeUtils.parameterize(ArrayList.class, variables);
+        final Map<TypeVariable<?>, Type> mapping = Collections.<TypeVariable<?>, Type>singletonMap(variables[0], String.class);
+        final Type unrolled = TypeUtils.unrollVariables(mapping, parameterizedType);
+        assertEquals(TypeUtils.parameterize(ArrayList.class, String.class), unrolled);
+    }
+
     @Test
     public void testParameterizeWithOwner() throws Exception {
         final Type owner = TypeUtils.parameterize(TypeUtilsTest.class, String.class);