JAVA-891: Added an additional check for NULL character to BasicBSONEncoder.

Author: jyemin

src/main/org/bson/BasicBSONEncoder.java

@@ -480,6 +480,11 @@ protected int _put( String str ){
         for ( int i=0; i<len; ){
             int c = Character.codePointAt( str , i );
 
+            if (c == 0x0) {
+                throw new BSONException(
+                        String.format("BSON cstring '%s' is not valid because it contains a null character at index %d", str, i));
+            }
+
             if ( c < 0x80 ){
                 _buf.write( (byte)c );
                 total += 1;

src/test/org/bson/BasicBSONEncoderTest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2008 - 2013 10gen, Inc. <http://10gen.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.bson;
+
+import org.bson.io.BasicOutputBuffer;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+public class BasicBSONEncoderTest extends Assert {
+
+    @Test(expectedExceptions = BSONException.class)
+    public void testNullCharacterInCString() {
+        BasicBSONEncoder encoder = new BasicBSONEncoder();
+        encoder.set(new BasicOutputBuffer());
+        encoder.writeCString("hell\u0000world");
+    }
+}