Google code should not be depending on this bug in the JDK, which is

martinrb · ejona86 · commit bec59eabee16 · 2015-11-06T14:37:59.000-08:00
due to be fixed in jdk9: (coll) Arrays.asList(x).toArray().getClass() should be Object[].class https://bugs.openjdk.java.net/browse/JDK-6260652 This change is not 100% compatible. If we have list = Arrays.asList("a", "b", "c"); then ((List)list).set(0, 1) will fail with ArrayStoreException, but this will not be true of its clone. Trying to patch that nano-bug via reflection or serialization will be slow and land you in different kind of hot water - not worth it. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=100143653
diff --git a/google-http-client/src/main/java/com/google/api/client/util/Data.java b/google-http-client/src/main/java/com/google/api/client/util/Data.java
@@ -219,8 +219,8 @@ public static <T> T clone(T data) {
       copy = (T) ((ArrayMap<?, ?>) data).clone();
     } else if ("java.util.Arrays$ArrayList".equals(dataClass.getName())) {
       // Arrays$ArrayList does not have a zero-arg constructor, so it has to handled specially.
-      // Although it appears as an Object[], arrayCopy shares the same type as the array originally
-      // passed to Arrays.asList() because Arrays$ArrayList uses clone() to create it.
+      // Arrays.asList(x).toArray() may or may not have the same runtime type as x.
+      // https://bugs.openjdk.java.net/browse/JDK-6260652
       Object[] arrayCopy = ((List<?>) data).toArray();
       deepCopy(arrayCopy, arrayCopy);
       copy = (T) Arrays.asList(arrayCopy);
diff --git a/google-http-client/src/test/java/com/google/api/client/util/DataTest.java b/google-http-client/src/test/java/com/google/api/client/util/DataTest.java
@@ -117,18 +117,19 @@ public void testClone_arrayMap() {
   }
 
   public void testClone_ArraysAsList() {
-    List<Object> orig = Arrays.<Object>asList("a", "b", "c", new ArrayList<Object>());
-    List<Object> result = Data.clone(orig);
-    assertTrue(orig != result);
-    assertEquals(orig, result);
-    assertTrue(orig.get(3) != result.get(3));
+    {
+      List<Object> orig = Arrays.<Object>asList("a", "b", "c", new ArrayList<Object>());
+      List<Object> result = Data.clone(orig);
+      assertTrue(orig != result);
+      assertEquals(orig, result);
+      assertTrue(orig.get(3) != result.get(3));
+    }
 
-    List list = Data.clone(Arrays.asList(new String[] {"a", "b", "c"}));
-    try {
-      list.set(0, new Object());
-      fail("Cloned list should be backed by String[], not Object[]");
-    } catch (ArrayStoreException e) {
-      // expected
+    {
+      List<String> orig = Arrays.asList(new String[] {"a", "b", "c"});
+      List<String> result = Data.clone(orig);
+      assertTrue(orig != result);
+      assertEquals(orig, result);
     }
   }
 
