From 7fed345f0a95396941d6b0bc6dafaeab0dca1b53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=AB=98=E9=93=81?= <shaojin.wensj@alibaba-inc.com>
Date: Wed, 17 Feb 2021 18:09:05 +0800
Subject: [PATCH] bug fix for WallFilter setLimit, fix #2649

---
 .../com/alibaba/druid/wall/WallProvider.java  | 15 ++++++++++++-
 .../filter/wall/WallSelectLimitTest_2.java    | 22 ++++++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/alibaba/druid/wall/WallProvider.java b/src/main/java/com/alibaba/druid/wall/WallProvider.java
index 95609632e0..854fe88437 100644
--- a/src/main/java/com/alibaba/druid/wall/WallProvider.java
+++ b/src/main/java/com/alibaba/druid/wall/WallProvider.java
@@ -34,6 +34,7 @@ import com.alibaba.druid.DbType;
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
 import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlHintStatement;
 import com.alibaba.druid.sql.parser.Lexer;
@@ -708,7 +709,19 @@ public abstract class WallProvider {
             }
         } else {
             if ((!updateCheckHandlerEnable) && sql.length() < MAX_SQL_LENGTH) {
-                sqlStat = addWhiteSql(sql, tableStat, context.getFunctionStats(), syntaxError);
+                boolean selectLimit = false;
+                if (config.getSelectLimit() > 0) {
+                    for (SQLStatement stmt : statementList) {
+                        if (stmt instanceof SQLSelectStatement) {
+                            selectLimit = true;
+                            break;
+                        }
+                    }
+                }
+
+                if (!selectLimit) {
+                    sqlStat = addWhiteSql(sql, tableStat, context.getFunctionStats(), syntaxError);
+                }
             }
         }
         
diff --git a/src/test/java/com/alibaba/druid/bvt/filter/wall/WallSelectLimitTest_2.java b/src/test/java/com/alibaba/druid/bvt/filter/wall/WallSelectLimitTest_2.java
index f4959f6638..471efe9a88 100644
--- a/src/test/java/com/alibaba/druid/bvt/filter/wall/WallSelectLimitTest_2.java
+++ b/src/test/java/com/alibaba/druid/bvt/filter/wall/WallSelectLimitTest_2.java
@@ -15,7 +15,6 @@
  */
 package com.alibaba.druid.bvt.filter.wall;
 
-import com.alibaba.druid.DbType;
 import com.alibaba.druid.sql.PagerUtils;
 import com.alibaba.druid.util.JdbcConstants;
 import com.alibaba.druid.wall.WallCheckResult;
@@ -42,6 +41,27 @@ public class WallSelectLimitTest_2 extends TestCase {
                 "LIMIT 10", resultSql);
     }
 
+    public void testMySql_0() throws Exception {
+        String sql = "select * from t";
+        WallProvider provider = new MySqlWallProvider(config);
+        {
+            WallCheckResult checkResult = provider.check(sql);
+            String resultSql = checkResult.getSql();
+            System.out.println(resultSql);
+            assertEquals("SELECT *\n" +
+                    "FROM t\n" +
+                    "LIMIT 1000", resultSql);
+        }
+        {
+            WallCheckResult checkResult = provider.check(sql);
+            String resultSql = checkResult.getSql();
+            System.out.println(resultSql);
+            assertEquals("SELECT *\n" +
+                    "FROM t\n" +
+                    "LIMIT 1000", resultSql);
+        }
+    }
+
     public void testPG() throws Exception {
         String sql = "select * from t limit 10";
         WallProvider provider = new PGWallProvider(config);