Bug #24010: INSERT INTO ... SELECT fails on unique constraint with data

it doesn't select.

This bug was fixed along with bug #16861: User defined variable can 
have a wrong value if a tmp table was used.

There the fix consisted of Item_func_set_user_var overloading the method
Item::save_in_field. Consider the query from the test case:


INSERT INTO foo( bar, baz )
SELECT 
  bar,
  @newBaz := 1 + baz
FROM 
  foo
WHERE 
  quux <= 0.1;

Here the assignment expression '@newBaz := 1 + baz' is represented by an 
Item_func_set_user_var. Its member method save_in_field, which writes the 
value of this assignment into the result field, writes the val_xxx() value, 
which is not updated at this point. In the fix introduced by the patch,
the save_in_field method reads the actual variable value instead.

See also comment for 
ChangeSet@1.2368.1.3, 2007-01-09 23:24:56+03:00, evgen@moonbone.local +4 -0
and comment for
Item_func_set_user_var::save_in_field (item_func.cc)

mysql-test/r/update.result

@@ -434,3 +434,22 @@ Handler_read_prev	0
 Handler_read_rnd	0
 Handler_read_rnd_next	21
 DROP TABLE t1;
+CREATE TABLE t1 (
+a INT(11),
+quux decimal( 31, 30 ),
+UNIQUE KEY bar (a),
+KEY quux (quux)
+);
+INSERT INTO
+t1 ( a, quux )
+VALUES
+( 1,    1 ),
+( 2,  0.1 );
+INSERT INTO t1( a )
+SELECT @newA := 1 + a FROM t1 WHERE quux <= 0.1;
+SELECT * FROM t1;
+a	quux
+1	1.000000000000000000000000000000
+2	0.100000000000000000000000000000
+3	NULL
+DROP TABLE t1;

mysql-test/t/update.test

@@ -342,3 +342,29 @@ UPDATE t1 SET user_id=null WHERE request_id=999999999999999999999999999999;
 show status like '%Handler_read%';
 
 DROP TABLE t1;
+
+#
+# Bug #24010: INSERT INTO ... SELECT fails on unique constraint with data it 
+# doesn't select
+#
+CREATE TABLE t1 (
+
+  a INT(11),
+  quux decimal( 31, 30 ),
+
+  UNIQUE KEY bar (a),
+  KEY quux (quux)
+);
+
+INSERT INTO
+ t1 ( a, quux )
+VALUES
+    ( 1,    1 ),
+    ( 2,  0.1 );
+
+INSERT INTO t1( a )
+  SELECT @newA := 1 + a FROM t1 WHERE quux <= 0.1;
+
+SELECT * FROM t1;
+
+DROP TABLE t1;