From d2b5e0bb940dbcf4dae0000a745cab58a351408e Mon Sep 17 00:00:00 2001
From: Sergey Glukhov <Sergey.Glukhov@sun.com>
Date: Tue, 9 Dec 2008 16:38:52 +0400
Subject: [PATCH] Bug#31291 ALTER TABLE CONVERT TO CHARACTER SET does not
 change some data types added ability for TINY[MEDIUM] text fields to be
 converted to greater subtype during alter if necessary(altered charset)

---
 mysql-test/r/alter_table.result | 16 ++++++++++++++++
 mysql-test/t/alter_table.test   | 13 +++++++++++++
 sql/sql_table.cc                |  4 +++-
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/alter_table.result b/mysql-test/r/alter_table.result
index 95c652055ec..d81086682f1 100644
--- a/mysql-test/r/alter_table.result
+++ b/mysql-test/r/alter_table.result
@@ -915,3 +915,19 @@ check table t1;
 Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
 drop table t1;
+create table t1 (a tinytext character set latin1);
+alter table t1 convert to character set utf8;
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` text
+) ENGINE=MyISAM DEFAULT CHARSET=utf8
+drop table t1;
+create table t1 (a mediumtext character set latin1);
+alter table t1 convert to character set utf8;
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` longtext
+) ENGINE=MyISAM DEFAULT CHARSET=utf8
+drop table t1;
diff --git a/mysql-test/t/alter_table.test b/mysql-test/t/alter_table.test
index bcca122f9f8..18481291bba 100644
--- a/mysql-test/t/alter_table.test
+++ b/mysql-test/t/alter_table.test
@@ -696,3 +696,16 @@ unlock tables;
 select * from t1;
 check table t1;
 drop table t1;
+
+
+#
+# Bug#31291 ALTER TABLE CONVERT TO CHARACTER SET does not change some data types
+#
+create table t1 (a tinytext character set latin1);
+alter table t1 convert to character set utf8;
+show create table t1;
+drop table t1;
+create table t1 (a mediumtext character set latin1);
+alter table t1 convert to character set utf8;
+show create table t1;
+drop table t1;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 8baeca9ccf7..eefe2a5596e 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -1535,7 +1535,9 @@ static bool prepare_blob_field(THD *thd, create_field *sql_field)
     
   if ((sql_field->flags & BLOB_FLAG) && sql_field->length)
   {
-    if (sql_field->sql_type == FIELD_TYPE_BLOB)
+    if (sql_field->sql_type == FIELD_TYPE_BLOB ||
+        sql_field->sql_type == FIELD_TYPE_TINY_BLOB ||
+        sql_field->sql_type == FIELD_TYPE_MEDIUM_BLOB)
     {
       /* The user has given a length to the blob column */
       sql_field->sql_type= get_blob_type_from_length(sql_field->length);