Merge "Make dumpHexString() tolerate null arrays."

am: a917c1db32

Change-Id: Ib0160e232cab0a713853a65eef26f7a02d65c1f1

core/java/com/android/internal/util/HexDump.java

@@ -16,18 +16,21 @@
 
 package com.android.internal.util;
 
+import android.annotation.Nullable;
+
 public class HexDump
 {
     private final static char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
     private final static char[] HEX_LOWER_CASE_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
 
-    public static String dumpHexString(byte[] array)
-    {
+    public static String dumpHexString(@Nullable byte[] array) {
+        if (array == null) return "(null)";
         return dumpHexString(array, 0, array.length);
     }
 
-    public static String dumpHexString(byte[] array, int offset, int length)
+    public static String dumpHexString(@Nullable byte[] array, int offset, int length)
     {
+        if (array == null) return "(null)";
         StringBuilder result = new StringBuilder();
 
         byte[] line = new byte[16];

core/tests/coretests/src/com/android/internal/util/HexDumpTest.java

@@ -25,4 +25,7 @@ public final class HexDumpTest extends TestCase {
         assertEquals("ABCDEF", HexDump.toHexString(
                 new byte[] { (byte) 0xab, (byte) 0xcd, (byte) 0xef }, true));
     }
+    public void testNullArray() {
+        assertEquals("(null)", HexDump.toHexString(null));
+    }
 }