Fixes #343 Accessing dynamic variable could cause BindingException when null is bound.

Author: harawata

src/main/java/org/apache/ibatis/scripting/xmltags/DynamicContext.java

@@ -106,7 +106,7 @@ public Object getProperty(Map context, Object target, Object name)
       Map map = (Map) target;
 
       Object result = map.get(name);
-      if (result != null) {
+      if (map.containsKey(name) || result != null) {
         return result;
       }
 

src/test/java/org/apache/ibatis/submitted/dynsql/DynSqlMapper.java

@@ -0,0 +1,23 @@
+/*-
+ *    Copyright 2009-2015 the original author or authors.
+ *
+ *    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.apache.ibatis.submitted.dynsql;
+
+import org.apache.ibatis.annotations.Param;
+
+public interface DynSqlMapper {
+  String selectDescription(@Param("p") String p);
+}

src/test/java/org/apache/ibatis/submitted/dynsql/DynSqlMapper.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+       Copyright 2009-2015 the original author or authors.
+
+       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.
+
+-->
+
+<!DOCTYPE mapper
+    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+
+<mapper namespace="org.apache.ibatis.submitted.dynsql.DynSqlMapper">
+  <select id="selectDescription" resultType="string">
+    <bind name="condition" value="p" />
+    SELECT description
+    FROM ibtest.names
+    <if test="condition == null">
+      WHERE id = 3
+    </if>
+  </select>
+</mapper>

src/test/java/org/apache/ibatis/submitted/dynsql/DynSqlTest.java

@@ -158,4 +158,16 @@ public void testOgnlStaticMethodCall() {
     }
   }
 
+  @Test
+  public void testBindNull() {
+    SqlSession sqlSession = sqlSessionFactory.openSession();
+    try {
+      DynSqlMapper mapper = sqlSession.getMapper(DynSqlMapper.class);
+      String description = mapper.selectDescription(null);
+      assertEquals("Pebbles", description);
+    } finally {
+      sqlSession.close();
+    }
+  }
+
 }

src/test/java/org/apache/ibatis/submitted/dynsql/MapperConfig.xml

@@ -38,6 +38,7 @@
 
   <mappers>
     <mapper resource="org/apache/ibatis/submitted/dynsql/DynSql.xml"/>
+    <mapper class="org.apache.ibatis.submitted.dynsql.DynSqlMapper" />
   </mappers>
 
 </configuration>

src/test/java/org/apache/ibatis/submitted/foreach/ForEachTest.java

@@ -107,4 +107,21 @@ public void shouldHandleMoreComplexNullItem() {
     }
   }
 
+  @Test
+  public void nullItemInContext() {
+    SqlSession sqlSession = sqlSessionFactory.openSession();
+    try {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      User user1 = new User();
+      user1.setId(3);
+      List<User> users = new ArrayList<User>();
+      users.add(user1);
+      users.add(null);
+      String name = mapper.selectWithNullItemCheck(users);
+      Assert.assertEquals("User3", name);
+    } finally {
+      sqlSession.close();
+    }
+  }
+
 }

src/test/java/org/apache/ibatis/submitted/foreach/Mapper.java

@@ -25,4 +25,6 @@ public interface Mapper {
 
   int countByBestFriend(List<User> users);
 
+  String selectWithNullItemCheck(List<User> users);
+
 }

src/test/java/org/apache/ibatis/submitted/foreach/Mapper.xml

@@ -50,4 +50,16 @@
       </where>
   </select>
 
+  <select id="selectWithNullItemCheck" resultType="string">
+    select name from users
+      <where>
+        id in
+        <foreach item="item" collection="list" separator="," open="(" close=")">
+          <if test="item != null">
+            #{item.id, jdbcType=NUMERIC}
+          </if>
+        </foreach>
+      </where>
+  </select>
+
 </mapper>