diff --git a/mysql-test/r/ctype_binary.result b/mysql-test/r/ctype_binary.result
index 291dcfdf92a..a80c52ebf9d 100644
--- a/mysql-test/r/ctype_binary.result
+++ b/mysql-test/r/ctype_binary.result
@@ -2046,7 +2046,7 @@ create table t2 as select concat(a) from t1;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `concat(a)` varbinary(2) DEFAULT NULL
+  `concat(a)` varbinary(4) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2;
 create table t1 (a year);
@@ -2355,7 +2355,7 @@ insert into t1 values (1);
 create view v1(a) as select concat(a) from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	varbinary(2)	YES		NULL	
+a	varbinary(4)	YES		NULL	
 select hex(a) from v1;
 hex(a)
 3031
diff --git a/mysql-test/r/ctype_cp1251.result b/mysql-test/r/ctype_cp1251.result
index 58f023b2b79..cff4f6b7442 100644
--- a/mysql-test/r/ctype_cp1251.result
+++ b/mysql-test/r/ctype_cp1251.result
@@ -2438,7 +2438,7 @@ create table t2 as select concat(a) from t1;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `concat(a)` varchar(2) CHARACTER SET cp1251 DEFAULT NULL
+  `concat(a)` varchar(4) CHARACTER SET cp1251 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2;
 create table t1 (a year);
@@ -2747,7 +2747,7 @@ insert into t1 values (1);
 create view v1(a) as select concat(a) from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	varchar(2)	YES		NULL	
+a	varchar(4)	YES		NULL	
 select hex(a) from v1;
 hex(a)
 3031
diff --git a/mysql-test/r/ctype_latin1.result b/mysql-test/r/ctype_latin1.result
index 2ecb9d6aeba..12a76302397 100644
--- a/mysql-test/r/ctype_latin1.result
+++ b/mysql-test/r/ctype_latin1.result
@@ -2465,7 +2465,7 @@ create table t2 as select concat(a) from t1;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `concat(a)` varchar(2) DEFAULT NULL
+  `concat(a)` varchar(4) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2;
 create table t1 (a year);
@@ -2774,7 +2774,7 @@ insert into t1 values (1);
 create view v1(a) as select concat(a) from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	varchar(2)	YES		NULL	
+a	varchar(4)	YES		NULL	
 select hex(a) from v1;
 hex(a)
 3031
diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index e687822c235..dc922f8490a 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -3299,7 +3299,7 @@ create table t2 as select concat(a) from t1;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `concat(a)` varchar(2) CHARACTER SET ucs2 DEFAULT NULL
+  `concat(a)` varchar(4) CHARACTER SET ucs2 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2;
 create table t1 (a year);
@@ -3608,7 +3608,7 @@ insert into t1 values (1);
 create view v1(a) as select concat(a) from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	varchar(2)	YES		NULL	
+a	varchar(4)	YES		NULL	
 select hex(a) from v1;
 hex(a)
 00300031
diff --git a/mysql-test/r/ctype_utf8.result b/mysql-test/r/ctype_utf8.result
index db981fbe298..cfbf6cee3a2 100644
--- a/mysql-test/r/ctype_utf8.result
+++ b/mysql-test/r/ctype_utf8.result
@@ -4177,7 +4177,7 @@ create table t2 as select concat(a) from t1;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
-  `concat(a)` varchar(2) CHARACTER SET utf8 DEFAULT NULL
+  `concat(a)` varchar(4) CHARACTER SET utf8 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1, t2;
 create table t1 (a year);
@@ -4486,7 +4486,7 @@ insert into t1 values (1);
 create view v1(a) as select concat(a) from t1;
 show columns from v1;
 Field	Type	Null	Key	Default	Extra
-a	varchar(2)	YES		NULL	
+a	varchar(4)	YES		NULL	
 select hex(a) from v1;
 hex(a)
 3031
diff --git a/mysql-test/r/distinct.result b/mysql-test/r/distinct.result
index b1cb70fa43c..74f2c19c8fe 100644
--- a/mysql-test/r/distinct.result
+++ b/mysql-test/r/distinct.result
@@ -794,3 +794,14 @@ DROP TABLE t1;
 SET @@sort_buffer_size = @old_sort_buffer_size;
 SET @@max_heap_table_size = @old_max_heap_table_size;
 End of 5.1 tests
+#
+# Bug #11744875: 4082: integer lengths cause truncation with distinct concat and innodb
+#
+CREATE TABLE t1 (a INT(1), b INT(1));
+INSERT INTO t1 VALUES (1111, 2222), (3333, 4444);
+SELECT DISTINCT CONCAT(a,b) AS c FROM t1 ORDER BY 1;
+c
+11112222
+33334444
+DROP TABLE t1;
+End of 5.5 tests
diff --git a/mysql-test/r/metadata.result b/mysql-test/r/metadata.result
index 480cec792c0..3418348854f 100644
--- a/mysql-test/r/metadata.result
+++ b/mysql-test/r/metadata.result
@@ -126,7 +126,7 @@ renamed
 1
 select * from v3 where renamed=1 group by renamed;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def		v3	v3	renamed	renamed	8	11	0	Y	32896	0	63
+def		v3	v3	renamed	renamed	8	12	0	Y	32896	0	63
 renamed
 drop table t1;
 drop view v1,v2,v3;
diff --git a/mysql-test/r/type_ranges.result b/mysql-test/r/type_ranges.result
index ac3d52b9ead..d99c2363d62 100644
--- a/mysql-test/r/type_ranges.result
+++ b/mysql-test/r/type_ranges.result
@@ -271,7 +271,7 @@ drop table t2;
 create table t2 (primary key (auto)) select auto+1 as auto,1 as t1, 'a' as t2, repeat('a',256) as t3, binary repeat('b',256) as t4, repeat('a',4096) as t5, binary repeat('b',4096) as t6, '' as t7, binary '' as t8 from t1;
 show full columns from t2;
 Field	Type	Collation	Null	Key	Default	Extra	Privileges	Comment
-auto	int(6) unsigned	NULL	NO	PRI	0		#	
+auto	int(11) unsigned	NULL	NO	PRI	0		#	
 t1	int(1)	NULL	NO		0		#	
 t2	varchar(1)	latin1_swedish_ci	NO				#	
 t3	varchar(256)	latin1_swedish_ci	NO				#	
diff --git a/mysql-test/t/distinct.test b/mysql-test/t/distinct.test
index bf4c23562cf..84073d15109 100644
--- a/mysql-test/t/distinct.test
+++ b/mysql-test/t/distinct.test
@@ -614,3 +614,16 @@ SET @@sort_buffer_size = @old_sort_buffer_size;
 SET @@max_heap_table_size = @old_max_heap_table_size;
 
 --echo End of 5.1 tests
+
+
+--echo #
+--echo # Bug #11744875: 4082: integer lengths cause truncation with distinct concat and innodb
+--echo #
+
+CREATE TABLE t1 (a INT(1), b INT(1));
+INSERT INTO t1 VALUES (1111, 2222), (3333, 4444);
+SELECT DISTINCT CONCAT(a,b) AS c FROM t1 ORDER BY 1;
+DROP TABLE t1;
+
+
+--echo End of 5.5 tests
diff --git a/sql/item.cc b/sql/item.cc
index 5e5e07203f9..2c0da80b43b 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -2011,6 +2011,61 @@ Item_field::Item_field(THD *thd, Item_field *item)
   collation.set(DERIVATION_IMPLICIT);
 }
 
+
+/**
+  Calculate the max column length not taking into account the
+  limitations over integer types.
+
+  When storing data into fields the server currently just ignores the
+  limits specified on integer types, e.g. 1234 can safely be stored in
+  an int(2) and will not cause an error.
+  Thus when creating temporary tables and doing transformations
+  we must adjust the maximum field length to reflect this fact.
+  We take the un-restricted maximum length and adjust it similarly to
+  how the declared length is adjusted wrt unsignedness etc.
+  TODO: this all needs to go when we disable storing 1234 in int(2).
+
+  @param field_par   Original field the use to calculate the lengths
+  @param max_length  Item's calculated explicit max length
+  @return            The adjusted max length
+*/
+
+inline static uint32
+adjust_max_effective_column_length(Field *field_par, uint32 max_length)
+{
+  uint32 new_max_length= field_par->max_display_length();
+  uint32 sign_length= (field_par->flags & UNSIGNED_FLAG) ? 0 : 1;
+
+  switch (field_par->type())
+  {
+  case MYSQL_TYPE_INT24:
+    /*
+      Compensate for MAX_MEDIUMINT_WIDTH being 1 too long (8)
+      compared to the actual number of digits that can fit into
+      the column.
+    */
+    new_max_length+= 1;
+    /* fall through */
+  case MYSQL_TYPE_LONG:
+  case MYSQL_TYPE_TINY:
+  case MYSQL_TYPE_SHORT:
+
+    /* Take out the sign and add a conditional sign */
+    new_max_length= new_max_length - 1 + sign_length;
+    break;
+
+  /* BINGINT is always 20 no matter the sign */
+  case MYSQL_TYPE_LONGLONG:
+  /* make gcc happy */
+  default:
+    break;
+  }
+
+  /* Adjust only if the actual precision based one is bigger than specified */
+  return new_max_length > max_length ? new_max_length : max_length;
+}
+
+
 void Item_field::set_field(Field *field_par)
 {
   field=result_field=field_par;			// for easy coding with fields
@@ -2024,6 +2079,9 @@ void Item_field::set_field(Field *field_par)
   collation.set(field_par->charset(), field_par->derivation(),
                 field_par->repertoire());
   fix_char_length(field_par->char_length());
+
+  max_length= adjust_max_effective_column_length(field_par, max_length);
+
   fixed= 1;
   if (field->table->s->tmp_table == SYSTEM_TMP_TABLE)
     any_privileges= 0;