fix: #1131 - github - add test case

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/plugins/PaginationInterceptor.java

@@ -19,6 +19,7 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Properties;
 
@@ -167,6 +168,12 @@ public class PaginationInterceptor extends SqlParserHandler implements Intercept
         if (CollectionUtils.isEmpty(ascs) && CollectionUtils.isEmpty(descs)) {
             return originalSql;
         }
+        if (ascs == null) {
+            ascs = Collections.EMPTY_LIST;
+        }
+        if (descs == null) {
+            descs = Collections.EMPTY_LIST;
+        }
         int size = ascs.size() + descs.size();
         try {
             Select selectStatement = (Select) CCJSqlParserUtil.parse(originalSql);