!366 修复当条件满足忽略规则，when又设置为true，NPE异常

Merge pull request !366 from 简单风/fix-bug-I86T6H

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryCondition.java

@@ -46,9 +46,22 @@ public class QueryCondition implements CloneSupport<QueryCondition> {
     //两个条件直接的连接符
     protected SqlConnector connector;
 
+    /**
+     * 是否为空条件，默认false
+     */
+    private boolean empty = false;
+
+    protected boolean notEmpty() {
+        return !empty;
+    }
+
+    protected QueryCondition setEmpty(boolean empty) {
+        this.empty = empty;
+        return this;
+    }
 
     public static QueryCondition createEmpty() {
-        return new QueryCondition().when(false);
+        return new QueryCondition().when(false).setEmpty(true);
     }
 
 
@@ -111,7 +124,9 @@ public class QueryCondition implements CloneSupport<QueryCondition> {
      * @return {@link QueryCondition}
      */
     public QueryCondition when(boolean effective) {
+        if (notEmpty()) {
             this.effective = effective;
+        }
         return this;
     }
 
@@ -123,7 +138,9 @@ public class QueryCondition implements CloneSupport<QueryCondition> {
      * @return {@link QueryCondition}
      */
     public QueryCondition when(BooleanSupplier fn) {
+        if (notEmpty()) {
             this.effective = fn.getAsBoolean();
+        }
         return this;
     }
 

mybatis-flex-core/src/test/java/com/mybatisflex/coretest/DynamicConditionTest.java

@@ -20,7 +20,6 @@ import com.mybatisflex.core.constant.SqlConnector;
 import com.mybatisflex.core.query.*;
 import com.mybatisflex.core.util.StringUtil;
 import org.junit.Test;
-
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
@@ -173,4 +172,16 @@ public class DynamicConditionTest {
         QueryColumnBehavior.setIgnoreFunction(Objects::isNull);
     }
 
+    @Test
+    public void test10() {
+        QueryWrapper queryWrapper = QueryWrapper.create()
+            .select()
+            .from(ACCOUNT)
+            // 满足忽略规则，但动态条件又是true
+            .where(ACCOUNT.USER_NAME.eq(null).when(true));
+        String sql = queryWrapper.toSQL();
+        System.out.println(sql);
+        assertEquals("SELECT * FROM `tb_account`", sql);
+    }
+
 }