Fix for bug#44743: Join in combination with concat does not always work

        bug#44766: valgrind error when using convert() in a subquery

Problem: input and output buffers may be the same 
converting a string to some charset. 
That may lead to wrong results/valgrind warnings.  

Fix: use different buffers.


mysql-test/r/cast.result:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - test result.
mysql-test/r/func_concat.result:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - test result.
mysql-test/t/cast.test:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - test case.
mysql-test/t/func_concat.test:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - test case.
sql/item.cc:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - comment added.
sql/item_strfunc.cc:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - '&args[0]->str_value' used as a parameter of args[0]->val_str(),
      as 'str' may be equal to 'str_value' which we use as the output buffer
      converting strings.
sql/sql_string.cc:
  Fix for bug#44743: Join in combination with concat does not always work
          bug#44766: valgrind error when using convert() in a subquery
    - input and output buffers must NOT be the same.

4 files changed, 93 insertions, 0 deletions

diff --git a/mysql-test/r/cast.result b/mysql-test/r/cast.result
index c1af92c5f8d..dd61396e485 100644
--- a/mysql-test/r/cast.result
+++ b/mysql-test/r/cast.result
@@ -439,3 +439,16 @@ HOUR(NULL)	MINUTE(NULL)	SECOND(NULL)
 NULL	NULL	NULL
 DROP TABLE t1;
 End of 5.0 tests
+#
+#  Bug #44766: valgrind error when using convert() in a subquery
+#
+CREATE TABLE t1(a tinyint);
+INSERT INTO t1 VALUES (127);
+SELECT 1 FROM
+(
+SELECT CONVERT(t2.a USING UTF8) FROM t1, t1 t2 LIMIT 1
+) AS s LIMIT 1;
+1
+1
+DROP TABLE t1;
+End of 5.1 tests
diff --git a/mysql-test/r/func_concat.result b/mysql-test/r/func_concat.result
index 7e7c163716e..75b4888fbb2 100644
--- a/mysql-test/r/func_concat.result
+++ b/mysql-test/r/func_concat.result
@@ -89,3 +89,34 @@ c1	c2
 	First
 DROP TABLE t1;
 # End of 5.0 tests
+#
+# Bug #44743: Join in combination with concat does not always work
+#
+CREATE TABLE t1 (
+a VARCHAR(100) NOT NULL DEFAULT '0',
+b VARCHAR(2) NOT NULL DEFAULT '',
+c VARCHAR(2) NOT NULL DEFAULT '',
+d TEXT NOT NULL,
+PRIMARY KEY (a, b, c),
+KEY (a)
+) DEFAULT CHARSET=utf8;
+INSERT INTO t1 VALUES ('gui_A', 'a', 'b', 'str1'),
+('gui_AB', 'a', 'b', 'str2'), ('gui_ABC', 'a', 'b', 'str3');
+CREATE TABLE t2 (
+a VARCHAR(100) NOT NULL DEFAULT '',
+PRIMARY KEY (a)
+) DEFAULT CHARSET=latin1;
+INSERT INTO t2 VALUES ('A'), ('AB'), ('ABC');
+SELECT CONCAT('gui_', t2.a), t1.d FROM t2 
+LEFT JOIN t1 ON t1.a = CONCAT('gui_', t2.a) AND t1.b = 'a' AND t1.c = 'b';
+CONCAT('gui_', t2.a)	d
+gui_A	str1
+gui_AB	str2
+gui_ABC	str3
+EXPLAIN SELECT CONCAT('gui_', t2.a), t1.d FROM t2 
+LEFT JOIN t1 ON t1.a = CONCAT('gui_', t2.a) AND t1.b = 'a' AND t1.c = 'b';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	index	NULL	PRIMARY	102	NULL	3	Using index
+1	SIMPLE	t1	eq_ref	PRIMARY,a	PRIMARY	318	func,const,const	1	
+DROP TABLE t1, t2;
+# End of 5.1 tests
diff --git a/mysql-test/t/cast.test b/mysql-test/t/cast.test
index 50865215944..8e60d548c2f 100644
--- a/mysql-test/t/cast.test
+++ b/mysql-test/t/cast.test
@@ -269,3 +269,18 @@ SELECT HOUR(NULL),
 DROP TABLE t1;
 
 --echo End of 5.0 tests
+
+--echo #
+--echo #  Bug #44766: valgrind error when using convert() in a subquery
+--echo #
+
+CREATE TABLE t1(a tinyint);
+INSERT INTO t1 VALUES (127);
+SELECT 1 FROM
+(
+ SELECT CONVERT(t2.a USING UTF8) FROM t1, t1 t2 LIMIT 1
+) AS s LIMIT 1;
+DROP TABLE t1;
+
+
+--echo End of 5.1 tests
diff --git a/mysql-test/t/func_concat.test b/mysql-test/t/func_concat.test
index f2aa0d004e5..1c7e5823fb2 100644
--- a/mysql-test/t/func_concat.test
+++ b/mysql-test/t/func_concat.test
@@ -78,3 +78,37 @@ SELECT * FROM t1 WHERE CONCAT(c1,' ',c2) REGEXP 'First.*';
 DROP TABLE t1;
 
 --echo # End of 5.0 tests
+
+
+--echo #
+--echo # Bug #44743: Join in combination with concat does not always work
+--echo #
+CREATE TABLE t1 (
+  a VARCHAR(100) NOT NULL DEFAULT '0',
+  b VARCHAR(2) NOT NULL DEFAULT '',
+  c VARCHAR(2) NOT NULL DEFAULT '',
+  d TEXT NOT NULL,
+  PRIMARY KEY (a, b, c),
+  KEY (a)
+) DEFAULT CHARSET=utf8;
+
+INSERT INTO t1 VALUES ('gui_A', 'a', 'b', 'str1'),
+  ('gui_AB', 'a', 'b', 'str2'), ('gui_ABC', 'a', 'b', 'str3');
+
+CREATE TABLE t2 (
+  a VARCHAR(100) NOT NULL DEFAULT '',
+  PRIMARY KEY (a)
+) DEFAULT CHARSET=latin1;
+
+INSERT INTO t2 VALUES ('A'), ('AB'), ('ABC');
+
+SELECT CONCAT('gui_', t2.a), t1.d FROM t2 
+  LEFT JOIN t1 ON t1.a = CONCAT('gui_', t2.a) AND t1.b = 'a' AND t1.c = 'b';
+
+EXPLAIN SELECT CONCAT('gui_', t2.a), t1.d FROM t2 
+  LEFT JOIN t1 ON t1.a = CONCAT('gui_', t2.a) AND t1.b = 'a' AND t1.c = 'b';
+
+DROP TABLE t1, t2;
+
+
+--echo # End of 5.1 tests