diff --git a/mysql-test/r/func_gconcat.result b/mysql-test/r/func_gconcat.result
index 71419b5b2c3..20df776ec1b 100644
--- a/mysql-test/r/func_gconcat.result
+++ b/mysql-test/r/func_gconcat.result
@@ -737,4 +737,30 @@ SELECT GROUP_CONCAT(DISTINCT UCASE(b)) FROM t1;
 GROUP_CONCAT(DISTINCT UCASE(b))
 ONE.1,TWO.2,ONE.3
 DROP TABLE t1;
+CREATE TABLE t1( a VARCHAR( 10 ), b INT );
+INSERT INTO t1 VALUES ( repeat( 'a', 10 ), 1), 
+( repeat( 'b', 10 ), 2);
+SET group_concat_max_len = 20;
+SELECT GROUP_CONCAT( a ) FROM t1;
+GROUP_CONCAT( a )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( DISTINCT a ) FROM t1;
+GROUP_CONCAT( DISTINCT a )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( a ORDER BY b ) FROM t1;
+GROUP_CONCAT( a ORDER BY b )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( DISTINCT a ORDER BY b ) FROM t1;
+GROUP_CONCAT( DISTINCT a ORDER BY b )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SET group_concat_max_len = DEFAULT;
+DROP TABLE t1;
 End of 5.0 tests
diff --git a/mysql-test/t/func_gconcat.test b/mysql-test/t/func_gconcat.test
index 0dd82864520..7771f216f69 100644
--- a/mysql-test/t/func_gconcat.test
+++ b/mysql-test/t/func_gconcat.test
@@ -507,4 +507,18 @@ SELECT GROUP_CONCAT(DISTINCT UCASE(a)) FROM t1;
 SELECT GROUP_CONCAT(DISTINCT UCASE(b)) FROM t1;
 DROP TABLE t1;
 
+#
+# Bug #28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated.
+#
+CREATE TABLE t1( a VARCHAR( 10 ), b INT );
+INSERT INTO t1 VALUES ( repeat( 'a', 10 ), 1), 
+                      ( repeat( 'b', 10 ), 2);
+SET group_concat_max_len = 20;
+SELECT GROUP_CONCAT( a ) FROM t1;
+SELECT GROUP_CONCAT( DISTINCT a ) FROM t1;  
+SELECT GROUP_CONCAT( a ORDER BY b ) FROM t1;          
+SELECT GROUP_CONCAT( DISTINCT a ORDER BY b ) FROM t1; 
+SET group_concat_max_len = DEFAULT;
+DROP TABLE t1;
+
 --echo End of 5.0 tests
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 4579ecd48ae..d6b31d43389 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -3339,6 +3339,10 @@ String* Item_func_group_concat::val_str(String* str)
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0;
+  if (!result.length() && tree)
+    /* Tree is used for sorting as in ORDER BY */
+    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
+              left_root_right);
   if (count_cut_values && !warning)
   {
     /*
@@ -3350,11 +3354,6 @@ String* Item_func_group_concat::val_str(String* str)
                           ER_CUT_VALUE_GROUP_CONCAT,
                           ER(ER_CUT_VALUE_GROUP_CONCAT));
   }
-  if (result.length())
-    return &result;
-  if (tree)
-    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
-              left_root_right);
   return &result;
 }