=== modified file 'mysql-test/r/func_gconcat.result'
--- mysql-test/r/func_gconcat.result	2013-01-08 20:21:28 +0000
+++ mysql-test/r/func_gconcat.result	2014-03-14 10:20:33 +0000
@@ -1091,3 +1091,85 @@ insert into t1 values ('a'),('b');
 select 1 from t1 where a in (select group_concat(a) from t1);
 1
 drop table t1;
+#
+#  WL#6098 Eliminate GROUP_CONCAT intermediate result limitation.
+#  Bug#13387020 GROUP_CONCAT WITH ORDER BY RESULTS ARE TRUNCATED.
+#
+SET group_concat_max_len= 9999999;
+CREATE TABLE t1 (f1 LONGTEXT , f2  INTEGER);
+INSERT INTO t1 VALUES (REPEAT('a', 500000), 0), (REPEAT('b', 500000), 1), (REPEAT('c', 500000), 2);
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1;
+LENGTH(GROUP_CONCAT(f1 ORDER BY f2))
+1500002
+SELECT LENGTH(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC)) FROM t1;
+LENGTH(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC))
+1500002
+SELECT SUBSTRING(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC), 1, 5) FROM t1;
+SUBSTRING(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC), 1, 5)
+ccccc
+SELECT LENGTH(GROUP_CONCAT(DISTINCT f1)) FROM t1;
+LENGTH(GROUP_CONCAT(DISTINCT f1))
+1500002
+SELECT LENGTH(GROUP_CONCAT(UPPER(f1) ORDER BY f2)) FROM t1;
+LENGTH(GROUP_CONCAT(UPPER(f1) ORDER BY f2))
+1500002
+SELECT LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1)) FROM t1;
+LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1))
+1500002
+SELECT SUBSTRING(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1), 1, 5) FROM t1;
+SUBSTRING(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1), 1, 5)
+AAAAA
+SELECT LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1))) FROM t1;
+LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1)))
+1500002
+CREATE TABLE t2 SELECT GROUP_CONCAT(f1 order by f2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `GROUP_CONCAT(f1 order by f2)` mediumtext
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+CREATE TABLE t2 SELECT GROUP_CONCAT(UPPER(f1) ORDER BY f2) FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `GROUP_CONCAT(UPPER(f1) ORDER BY f2)` mediumtext
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t2;
+SET group_concat_max_len= DEFAULT;
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1;
+LENGTH(GROUP_CONCAT(f1 ORDER BY f2))
+1024
+Warnings:
+Warning	1260	Row 2 was cut by GROUP_CONCAT()
+SET group_concat_max_len= 499999;
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 WHERE f2 = 0;
+LENGTH(GROUP_CONCAT(f1 ORDER BY f2))
+499999
+Warnings:
+Warning	1260	Row 1 was cut by GROUP_CONCAT()
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 GROUP BY f2;
+LENGTH(GROUP_CONCAT(f1 ORDER BY f2))
+499999
+499999
+499999
+Warnings:
+Warning	1260	Row 1 was cut by GROUP_CONCAT()
+Warning	1260	Row 2 was cut by GROUP_CONCAT()
+Warning	1260	Row 3 was cut by GROUP_CONCAT()
+INSERT INTO t1 VALUES (REPEAT('a', 499999), 3), (REPEAT('b', 500000), 4);
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 GROUP BY f2;
+LENGTH(GROUP_CONCAT(f1 ORDER BY f2))
+499999
+499999
+499999
+499999
+499999
+Warnings:
+Warning	1260	Row 1 was cut by GROUP_CONCAT()
+Warning	1260	Row 2 was cut by GROUP_CONCAT()
+Warning	1260	Row 3 was cut by GROUP_CONCAT()
+Warning	1260	Row 5 was cut by GROUP_CONCAT()
+DROP TABLE t1;
+SET group_concat_max_len= DEFAULT;
+End of 5.6 tests

=== modified file 'mysql-test/t/func_gconcat.test'
--- mysql-test/t/func_gconcat.test	2014-02-27 11:00:16 +0000
+++ mysql-test/t/func_gconcat.test	2014-03-14 10:20:12 +0000
@@ -803,3 +803,46 @@ create table t1 (a char(1) character set
 insert into t1 values ('a'),('b');
 select 1 from t1 where a in (select group_concat(a) from t1);
 drop table t1;
+
+--echo #
+--echo #  WL#6098 Eliminate GROUP_CONCAT intermediate result limitation.
+--echo #  Bug#13387020 GROUP_CONCAT WITH ORDER BY RESULTS ARE TRUNCATED.
+--echo #
+
+
+SET group_concat_max_len= 9999999;
+CREATE TABLE t1 (f1 LONGTEXT , f2  INTEGER);
+INSERT INTO t1 VALUES (REPEAT('a', 500000), 0), (REPEAT('b', 500000), 1), (REPEAT('c', 500000), 2);
+
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1;
+SELECT LENGTH(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC)) FROM t1;
+SELECT SUBSTRING(GROUP_CONCAT(DISTINCT f1 ORDER BY f1 DESC), 1, 5) FROM t1;
+SELECT LENGTH(GROUP_CONCAT(DISTINCT f1)) FROM t1;
+
+SELECT LENGTH(GROUP_CONCAT(UPPER(f1) ORDER BY f2)) FROM t1;
+SELECT LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1)) FROM t1;
+SELECT SUBSTRING(GROUP_CONCAT(DISTINCT UPPER(f1) ORDER BY f1), 1, 5) FROM t1;
+SELECT LENGTH(GROUP_CONCAT(DISTINCT UPPER(f1))) FROM t1;
+
+CREATE TABLE t2 SELECT GROUP_CONCAT(f1 order by f2) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+CREATE TABLE t2 SELECT GROUP_CONCAT(UPPER(f1) ORDER BY f2) FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t2;
+
+SET group_concat_max_len= DEFAULT;
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1;
+
+SET group_concat_max_len= 499999;
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 WHERE f2 = 0;
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 GROUP BY f2;
+
+INSERT INTO t1 VALUES (REPEAT('a', 499999), 3), (REPEAT('b', 500000), 4);
+SELECT LENGTH(GROUP_CONCAT(f1 ORDER BY f2)) FROM t1 GROUP BY f2;
+
+DROP TABLE t1;
+SET group_concat_max_len= DEFAULT;
+
+--echo End of 5.6 tests