bk commit into 5.1 tree (kaa:1.2562) BUG#33969

[Alexey Kopytov]

Below is the list of changes that have just been committed into a local
5.1 repository of kaa.  When kaa does a push these changes
will be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2008-04-23 09:52:53+04:00, kaa@kaamos.(none) +4 -0
  Fix for bug #33969: Updating a text field via a left join
  
  When creating a temporary TEXT/BLOB field from an Item in
  Item::make_string_field(), the field's type was unconditionally set
  to the one corresponding to the maximum length (i.e. LONGTEXT/
  LONGBLOB). This resulted in problems when exactly the same TEXT/BLOB
  is type required in cases like CREATE ... SELECT or creating internal
  temporary tables for joins.
  
  Fixed by calling a different constructor for Field_blob so that an
  appropriate type is used depending on the Item's max_length value.

  mysql-test/r/type_blob.result@stripped, 2008-04-23 09:52:52+04:00, kaa@kaamos.(none) +18 -0
    Added a test case for bug #33969.

  mysql-test/r/type_ranges.result@stripped, 2008-04-23 09:52:52+04:00, kaa@kaamos.(none) +2 -2
    Fixed a test that relied on the old behavior.

  mysql-test/t/type_blob.test@stripped, 2008-04-23 09:52:52+04:00, kaa@kaamos.(none) +20 -0
    Added a test case for bug #33969.

  sql/item.cc@stripped, 2008-04-23 09:52:52+04:00, kaa@kaamos.(none) +1 -1
    Use a different constructor for Field_blob in
    Item::make_string_field() so that set_packlength is set to adjust the
    type of the TEXT/BLOB field being created.

diff -Nrup a/mysql-test/r/type_blob.result b/mysql-test/r/type_blob.result
--- a/mysql-test/r/type_blob.result	2008-02-12 22:09:14 +03:00
+++ b/mysql-test/r/type_blob.result	2008-04-23 09:52:52 +04:00
@@ -822,3 +822,21 @@ LENGTH(c)	CHAR_LENGTH(c)
 65535	65535
 DROP TABLE t;
 End of 5.0 tests
+CREATE TABLE t1(id INT NOT NULL);
+CREATE TABLE t2(id INT NOT NULL, c TEXT NOT NULL);
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (1, '');
+UPDATE t2 SET c = REPEAT('1', 70000);
+Warnings:
+Warning	1265	Data truncated for column 'c' at row 1
+SELECT LENGTH(c) FROM t2;
+LENGTH(c)
+65535
+UPDATE t1 LEFT JOIN t2 USING(id) SET t2.c = REPEAT('1', 70000) WHERE t1.id = 1;
+Warnings:
+Warning	1265	Data truncated for column 'c' at row 1
+SELECT LENGTH(c) FROM t2;
+LENGTH(c)
+65535
+DROP TABLE t1, t2;
+End of 5.1 tests
diff -Nrup a/mysql-test/r/type_ranges.result b/mysql-test/r/type_ranges.result
--- a/mysql-test/r/type_ranges.result	2007-11-13 16:22:36 +03:00
+++ b/mysql-test/r/type_ranges.result	2008-04-23 09:52:52 +04:00
@@ -276,8 +276,8 @@ t1	int(1)	NULL	NO		0		#	
 t2	varchar(1)	latin1_swedish_ci	NO				#	
 t3	varchar(256)	latin1_swedish_ci	NO				#	
 t4	varbinary(256)	NULL	NO				#	
-t5	longtext	latin1_swedish_ci	NO		NULL		#	
-t6	longblob	NULL	NO		NULL		#	
+t5	text	latin1_swedish_ci	NO		NULL		#	
+t6	blob	NULL	NO		NULL		#	
 t7	char(0)	latin1_swedish_ci	NO				#	
 t8	binary(0)	NULL	NO				#	
 select t1,t2,length(t3),length(t4),length(t5),length(t6),t7,t8 from t2;
diff -Nrup a/mysql-test/t/type_blob.test b/mysql-test/t/type_blob.test
--- a/mysql-test/t/type_blob.test	2007-11-23 12:53:27 +03:00
+++ b/mysql-test/t/type_blob.test	2008-04-23 09:52:52 +04:00
@@ -448,3 +448,23 @@ SELECT LENGTH(c), CHAR_LENGTH(c) FROM t;
 DROP TABLE t;
 
 --echo End of 5.0 tests
+
+#
+# Bug #33969: Updating a text field via a left join
+#
+
+CREATE TABLE t1(id INT NOT NULL);
+CREATE TABLE t2(id INT NOT NULL, c TEXT NOT NULL);
+
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (1, '');
+
+UPDATE t2 SET c = REPEAT('1', 70000);
+SELECT LENGTH(c) FROM t2;
+
+UPDATE t1 LEFT JOIN t2 USING(id) SET t2.c = REPEAT('1', 70000) WHERE t1.id = 1;
+SELECT LENGTH(c) FROM t2;
+
+DROP TABLE t1, t2;
+
+--echo End of 5.1 tests
diff -Nrup a/sql/item.cc b/sql/item.cc
--- a/sql/item.cc	2008-03-12 11:21:09 +03:00
+++ b/sql/item.cc	2008-04-23 09:52:52 +04:00
@@ -4519,7 +4519,7 @@ Field *Item::make_string_field(TABLE *ta
   DBUG_ASSERT(collation.collation);
   if (max_length/collation.collation->mbmaxlen > CONVERT_IF_BIGGER_TO_BLOB)
     field= new Field_blob(max_length, maybe_null, name,
-                          collation.collation);
+                          collation.collation, TRUE);
   /* Item_type_holder holds the exact type, do not change it */
   else if (max_length > 0 &&
       (type() != Item::TYPE_HOLDER || field_type() != MYSQL_TYPE_STRING))