From 879878e43d5ffd2bf4d18ffe4d0186f8926e58ca Mon Sep 17 00:00:00 2001
From: Varun Gupta <varun.gupta@mariadb.com>
Date: Thu, 2 May 2019 14:38:43 +0530
Subject: [PATCH] MDEV-18943: Group Concat with limit not working with views

Adjusted the Item_func_group_concat::print function to take into account
limit if present with GROUP_CONCAT
---
 mysql-test/main/func_gconcat.result | 14 ++++++++++++++
 mysql-test/main/func_gconcat.test   | 12 ++++++++++++
 sql/item_sum.cc                     | 14 +++++++++++++-
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/mysql-test/main/func_gconcat.result b/mysql-test/main/func_gconcat.result
index 723a1952d79..1701bb364e8 100644
--- a/mysql-test/main/func_gconcat.result
+++ b/mysql-test/main/func_gconcat.result
@@ -1378,5 +1378,19 @@ group_concat(a,b limit ?)
 1a,1b,2x,2y
 drop table t2;
 #
+# MDEV-18943: Group Concat with limit not working with views
+#
+create table t1 (a int, b varchar(10));
+insert into t1 values(1,'a'),(1,'b'),(NULL,'c'),(2,'x'),(2,'y');
+select group_concat(a,b limit 2) from t1;
+group_concat(a,b limit 2)
+1a,1b
+create view v1 as select group_concat(a,b limit 2) from t1;
+select * from v1;
+group_concat(a,b limit 2)
+1a,1b
+drop view v1;
+drop table t1;
+#
 # End of 10.3 tests
 #
diff --git a/mysql-test/main/func_gconcat.test b/mysql-test/main/func_gconcat.test
index 5cbc6969e02..b8ab96bdea4 100644
--- a/mysql-test/main/func_gconcat.test
+++ b/mysql-test/main/func_gconcat.test
@@ -985,6 +985,18 @@ prepare STMT from 'select group_concat(a,b limit ?) from t2';
 execute STMT using @x;
 drop table t2;
 
+--echo #
+--echo # MDEV-18943: Group Concat with limit not working with views
+--echo #
+
+create table t1 (a int, b varchar(10));
+insert into t1 values(1,'a'),(1,'b'),(NULL,'c'),(2,'x'),(2,'y');
+select group_concat(a,b limit 2) from t1;
+create view v1 as select group_concat(a,b limit 2) from t1;
+select * from v1;
+drop view v1;
+drop table t1;
+
 --echo #
 --echo # End of 10.3 tests
 --echo #
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 4e449198fe0..ce0c9d3e944 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -4172,7 +4172,19 @@ void Item_func_group_concat::print(String *str, enum_query_type query_type)
   }
   str->append(STRING_WITH_LEN(" separator \'"));
   str->append_for_single_quote(separator->ptr(), separator->length());
-  str->append(STRING_WITH_LEN("\')"));
+  str->append(STRING_WITH_LEN("\'"));
+
+  if (limit_clause)
+  {
+    str->append(STRING_WITH_LEN(" limit "));
+    if (offset_limit)
+    {
+      offset_limit->print(str, query_type);
+      str->append(',');
+    }
+    row_limit->print(str, query_type);
+  }
+  str->append(STRING_WITH_LEN(")"));
 }