1 files changed, 13 insertions, 1 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/MapFieldLite.java b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
index 42640279..a8b3dd88 100644
--- a/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.EnumLite;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.EnumLite;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -88,6 +89,9 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
 
   @Override public V put(K key, V value) {
     ensureMutable();
+    checkNotNull(key);
+
+    checkNotNull(value);
     return super.put(key, value);
   }
 
@@ -97,6 +101,7 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
 
   @Override public void putAll(Map<? extends K, ? extends V> m) {
     ensureMutable();
+    checkForNullKeysAndValues(m);
     super.putAll(m);
   }
 
@@ -105,6 +110,13 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
     return super.remove(key);
   }
 
+  private static void checkForNullKeysAndValues(Map<?, ?> m) {
+    for (Object key : m.keySet()) {
+      checkNotNull(key);
+      checkNotNull(m.get(key));
+    }
+  }
+
   private static boolean equals(Object a, Object b) {
     if (a instanceof byte[] && b instanceof byte[]) {
       return Arrays.equals((byte[]) a, (byte[]) b);