1 files changed, 39 insertions, 1 deletions
diff --git a/java/core/src/test/java/com/google/protobuf/MapTest.java b/java/core/src/test/java/com/google/protobuf/MapTest.java
index e0d3f0cd..45019537 100644
--- a/java/core/src/test/java/com/google/protobuf/MapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
@@ -30,7 +30,7 @@
 
 package com.google.protobuf;
 
-
+import static org.junit.Assert.assertArrayEquals;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
@@ -864,6 +864,7 @@ public class MapTest extends TestCase {
     assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
   }
 
+  // See additional coverage in TextFormatTest.java.
   public void testTextFormat() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
     setMapValuesUsingAccessors(builder);
@@ -1483,4 +1484,41 @@ public class MapTest extends TestCase {
     map.put(key3, value3);
     return map;
   }
+
+  public void testMap_withNulls() {
+    TestMap.Builder builder = TestMap.newBuilder();
+
+    try {
+      builder.putStringToInt32Field(null, 3);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllStringToInt32Field(newMap(null, 3, "hi", 4));
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putInt32ToMessageField(3, null);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllInt32ToMessageField(
+          MapTest.<Integer, MessageValue>newMap(4, null, 5, null));
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllInt32ToMessageField(null);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    assertArrayEquals(new byte[0], builder.build().toByteArray());
+  }
 }