Merge bk@192.168.21.1:mysql-5.0

into  mysql.com:/d2/hf/mrg/mysql-5.0-opt


mysql-test/r/ps.result:
  Auto merged
mysql-test/t/ps.test:
  Auto merged
sql/item.cc:
  Auto merged

mysql-test/r/bigint.result

@@ -352,3 +352,13 @@ select c1 mod 50 as result from t1;
 result
 6
 drop table t1;
+select cast(19999999999999999999 as signed);
+cast(19999999999999999999 as signed)
+9223372036854775807
+Warnings:
+Error	1292	Truncated incorrect DECIMAL value: ''
+select cast(-19999999999999999999 as signed);
+cast(-19999999999999999999 as signed)
+-9223372036854775808
+Warnings:
+Error	1292	Truncated incorrect DECIMAL value: ''

mysql-test/r/func_gconcat.result

@@ -737,4 +737,30 @@ SELECT GROUP_CONCAT(DISTINCT UCASE(b)) FROM t1;
 GROUP_CONCAT(DISTINCT UCASE(b))
 ONE.1,TWO.2,ONE.3
 DROP TABLE t1;
+CREATE TABLE t1( a VARCHAR( 10 ), b INT );
+INSERT INTO t1 VALUES ( repeat( 'a', 10 ), 1), 
+( repeat( 'b', 10 ), 2);
+SET group_concat_max_len = 20;
+SELECT GROUP_CONCAT( a ) FROM t1;
+GROUP_CONCAT( a )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( DISTINCT a ) FROM t1;
+GROUP_CONCAT( DISTINCT a )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( a ORDER BY b ) FROM t1;
+GROUP_CONCAT( a ORDER BY b )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SELECT GROUP_CONCAT( DISTINCT a ORDER BY b ) FROM t1;
+GROUP_CONCAT( DISTINCT a ORDER BY b )
+aaaaaaaaaa,bbbbbbbbb
+Warnings:
+Warning	1260	1 line(s) were cut by GROUP_CONCAT()
+SET group_concat_max_len = DEFAULT;
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/r/func_group.result

@@ -1330,4 +1330,51 @@ SELECT a,AVG(DISTINCT b) AS average FROM t1 GROUP BY a HAVING average > 50;
 a	average
 1	32768.5000
 DROP TABLE t1;
+CREATE TABLE t1 ( a INT, b INT, KEY(a) );
+INSERT INTO t1 VALUES (NULL, 1), (NULL, 2);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT MIN(a), MIN(b) FROM t1;
+MIN(a)	MIN(b)
+NULL	1
+CREATE TABLE t2( a INT, b INT, c INT, KEY(a, b) );
+INSERT INTO t2 ( a, b, c ) VALUES ( 1, NULL, 2 ), ( 1, 3, 4 ), ( 1, 4, 4 );
+EXPLAIN SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ref	a	a	5	const	2	Using where
+SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
+MIN(b)	MIN(c)
+3	2
+CREATE TABLE t3 (a INT, b INT, c int, KEY(a, b));
+INSERT INTO t3 VALUES (1, NULL, 1), (2, NULL, 2),  (2, NULL, 2),  (3, NULL, 3);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t3 where a = 2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+SELECT MIN(a), MIN(b) FROM t3 where a = 2;
+MIN(a)	MIN(b)
+2	NULL
+CREATE TABLE t4 (a INT, b INT, c int, KEY(a, b));
+INSERT INTO t4 VALUES (1, 1, 1), (2, NULL, 2),  (2, NULL, 2),  (3, 1, 3);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t4 where a = 2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+SELECT MIN(a), MIN(b) FROM t4 where a = 2;
+MIN(a)	MIN(b)
+2	NULL
+SELECT MIN(b), min(c) FROM t4 where a = 2;
+MIN(b)	min(c)
+NULL	2
+CREATE TABLE t5( a INT, b INT, KEY( a, b) );
+INSERT INTO t5 VALUES( 1, 1 ), ( 1, 2 );
+EXPLAIN SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
+MIN(a)	MIN(b)
+1	1
+SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1 and b > 1;
+MIN(a)	MIN(b)
+1	2
+DROP TABLE t1, t2, t3, t4, t5;
 End of 5.0 tests

mysql-test/r/innodb_mysql.result

@@ -144,6 +144,27 @@ SELECT * FROM t1;
 c1	cnt
 1a	2
 DROP TABLE t1;
+CREATE TABLE t1 (
+a1 decimal(10,0) DEFAULT NULL,
+a2 blob,
+a3 time DEFAULT NULL,
+a4 blob,
+a5 char(175) DEFAULT NULL,
+a6 timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+a7 tinyblob,
+INDEX idx (a6,a7(239),a5)
+) ENGINE=InnoDB;
+EXPLAIN SELECT a4 FROM t1 WHERE
+a6=NULL AND
+a4='UNcT5pIde4I6c2SheTo4gt92OV1jgJCVkXmzyf325R1DwLURkbYHwhydANIZMbKTgdcR5xS';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT t1.a4 FROM t1, t1 t WHERE
+t.a6=t.a6 AND t1.a6=NULL AND
+t1.a4='UNcT5pIde4I6c2SheTo4gt92OV1jgJCVkXmzyf325R1DwLURkbYHwhydANIZMbKTgdcR5xS';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+DROP TABLE t1;
 End of 4.1 tests
 create table t1m (a int) engine=myisam;
 create table t1i (a int) engine=innodb;

mysql-test/r/ps.result

@@ -1114,6 +1114,28 @@ execute stmt;
 show create table t1;
 drop table t1;
 deallocate prepare stmt;
+CREATE TABLE t1(a int);
+INSERT INTO t1 VALUES (2), (3), (1);
+PREPARE st1 FROM
+'(SELECT a FROM t1) UNION (SELECT a+10 FROM t1) ORDER BY RAND()*0+a';
+EXECUTE st1;
+a
+1
+2
+3
+11
+12
+13
+EXECUTE st1;
+a
+1
+2
+3
+11
+12
+13
+DEALLOCATE PREPARE st1;
+DROP TABLE t1;
 End of 4.1 tests.
 create table t1 (a varchar(20));
 insert into t1 values ('foo');

mysql-test/r/subselect.result

@@ -4041,4 +4041,34 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 DROP TABLE t1;
+CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
+INSERT INTO t1 VALUES
+(3,'FL'), (2,'GA'), (4,'FL'), (1,'GA'), (5,'NY'), (7,'FL'), (6,'NY');
+CREATE TABLE t2 (id int NOT NULL, INDEX idx(id));
+INSERT INTO t2 VALUES (7), (5), (1), (3);
+SELECT id, st FROM t1 
+WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
+id	st
+3	FL
+1	GA
+7	FL
+SELECT id, st FROM t1 
+WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
+GROUP BY id;
+id	st
+1	GA
+3	FL
+7	FL
+SELECT id, st FROM t1 
+WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
+id	st
+2	GA
+4	FL
+SELECT id, st FROM t1 
+WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
+GROUP BY id;
+id	st
+2	GA
+4	FL
+DROP TABLE t1,t2;
 End of 5.0 tests.

mysql-test/r/type_datetime.result

@@ -346,3 +346,33 @@ call test27759();
 a	b	a_then_b	b_then_a	c_then_a
 2007-04-10	2007-04-11	2007-04-10	2007-04-10	2004-04-09 00:00:00
 drop procedure test27759;
+create table t1 (f1 date);
+insert into t1 values (curdate());
+select left(f1,10) = curdate() from t1;
+left(f1,10) = curdate()
+1
+drop table t1;
+create table t1(f1 date);
+insert into t1 values('01-01-01'),('02-02-02'),('01-01-01'),('02-02-02');
+set @bug28261='';
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+if(@bug28261 = f1, '', @bug28261:= f1)
+2001-01-01
+2002-02-02
+2001-01-01
+2002-02-02
+Warnings:
+Warning	1292	Incorrect date value: '' for column 'f1' at row 1
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+if(@bug28261 = f1, '', @bug28261:= f1)
+2001-01-01
+2002-02-02
+2001-01-01
+2002-02-02
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+if(@bug28261 = f1, '', @bug28261:= f1)
+2001-01-01
+2002-02-02
+2001-01-01
+2002-02-02
+drop table t1;

mysql-test/t/bigint.test

@@ -288,3 +288,9 @@ insert into t1 values (10000002383263201056);
 select c1 mod 50 as result from t1;
 drop table t1;
 
+#
+# Bug #8663 cant use bgint unsigned as input to cast
+#
+
+select cast(19999999999999999999 as signed);
+select cast(-19999999999999999999 as signed);

mysql-test/t/func_gconcat.test

@@ -507,4 +507,18 @@ SELECT GROUP_CONCAT(DISTINCT UCASE(a)) FROM t1;
 SELECT GROUP_CONCAT(DISTINCT UCASE(b)) FROM t1;
 DROP TABLE t1;
 
+#
+# Bug #28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated.
+#
+CREATE TABLE t1( a VARCHAR( 10 ), b INT );
+INSERT INTO t1 VALUES ( repeat( 'a', 10 ), 1), 
+                      ( repeat( 'b', 10 ), 2);
+SET group_concat_max_len = 20;
+SELECT GROUP_CONCAT( a ) FROM t1;
+SELECT GROUP_CONCAT( DISTINCT a ) FROM t1;  
+SELECT GROUP_CONCAT( a ORDER BY b ) FROM t1;          
+SELECT GROUP_CONCAT( DISTINCT a ORDER BY b ) FROM t1; 
+SET group_concat_max_len = DEFAULT;
+DROP TABLE t1;
+
 --echo End of 5.0 tests

mysql-test/t/func_group.test

@@ -827,4 +827,38 @@ SELECT a,AVG(DISTINCT b) AS average FROM t1 GROUP BY a HAVING average > 50;
 
 DROP TABLE t1;
 
+#
+# Bug #27573: MIN() on an indexed column which is always NULL sets _other_ 
+# results to NULL
+#
+CREATE TABLE t1 ( a INT, b INT, KEY(a) );
+INSERT INTO t1 VALUES (NULL, 1), (NULL, 2);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t1;
+SELECT MIN(a), MIN(b) FROM t1;
+
+CREATE TABLE t2( a INT, b INT, c INT, KEY(a, b) );
+INSERT INTO t2 ( a, b, c ) VALUES ( 1, NULL, 2 ), ( 1, 3, 4 ), ( 1, 4, 4 );
+EXPLAIN SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
+SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
+
+CREATE TABLE t3 (a INT, b INT, c int, KEY(a, b));
+INSERT INTO t3 VALUES (1, NULL, 1), (2, NULL, 2),  (2, NULL, 2),  (3, NULL, 3);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t3 where a = 2;
+SELECT MIN(a), MIN(b) FROM t3 where a = 2;
+
+CREATE TABLE t4 (a INT, b INT, c int, KEY(a, b));
+INSERT INTO t4 VALUES (1, 1, 1), (2, NULL, 2),  (2, NULL, 2),  (3, 1, 3);
+EXPLAIN SELECT MIN(a), MIN(b) FROM t4 where a = 2;
+SELECT MIN(a), MIN(b) FROM t4 where a = 2;
+SELECT MIN(b), min(c) FROM t4 where a = 2;
+
+CREATE TABLE t5( a INT, b INT, KEY( a, b) ); 
+INSERT INTO t5 VALUES( 1, 1 ), ( 1, 2 );
+EXPLAIN SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
+SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
+SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1 and b > 1;
+
+DROP TABLE t1, t2, t3, t4, t5;
+
+###
 --echo End of 5.0 tests

mysql-test/t/innodb_mysql.test

@@ -169,6 +169,31 @@ INSERT INTO t1 (c1) VALUES ('1b') ON DUPLICATE KEY UPDATE cnt=cnt+1;
 SELECT * FROM t1;
 DROP TABLE t1;
 
+#
+# Bug #28272: EXPLAIN for SELECT from an empty InnoDB table
+#
+
+CREATE TABLE t1 (
+  a1 decimal(10,0) DEFAULT NULL,
+  a2 blob,
+  a3 time DEFAULT NULL,
+  a4 blob,
+  a5 char(175) DEFAULT NULL,
+  a6 timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+  a7 tinyblob,
+  INDEX idx (a6,a7(239),a5)
+) ENGINE=InnoDB;
+
+EXPLAIN SELECT a4 FROM t1 WHERE
+a6=NULL AND
+a4='UNcT5pIde4I6c2SheTo4gt92OV1jgJCVkXmzyf325R1DwLURkbYHwhydANIZMbKTgdcR5xS';
+
+EXPLAIN SELECT t1.a4 FROM t1, t1 t WHERE
+t.a6=t.a6 AND t1.a6=NULL AND
+t1.a4='UNcT5pIde4I6c2SheTo4gt92OV1jgJCVkXmzyf325R1DwLURkbYHwhydANIZMbKTgdcR5xS';
+
+DROP TABLE t1;
+
 --echo End of 4.1 tests
 #
 # Bug #12882  	min/max inconsistent on empty table

mysql-test/t/ps.test

@@ -1194,6 +1194,24 @@ show create table t1;
 --enable_warnings
 drop table t1;
 deallocate prepare stmt;
+#
+
+#
+# Bug #27937: crash on the second execution for prepared statement 
+#             from UNION with ORDER BY an expression containing RAND()
+#
+
+CREATE TABLE t1(a int);
+INSERT INTO t1 VALUES (2), (3), (1);
+
+PREPARE st1 FROM
+  '(SELECT a FROM t1) UNION (SELECT a+10 FROM t1) ORDER BY RAND()*0+a';
+
+EXECUTE st1;
+EXECUTE st1;
+
+DEALLOCATE PREPARE st1;
+DROP TABLE t1;
 
 --echo End of 4.1 tests.
 

mysql-test/t/subselect.test

@@ -2882,4 +2882,28 @@ INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 DROP TABLE t1;
 
+#
+# Bug #28377: grouping query with a correlated subquery in WHERE condition
+#  
+
+CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
+INSERT INTO t1 VALUES
+  (3,'FL'), (2,'GA'), (4,'FL'), (1,'GA'), (5,'NY'), (7,'FL'), (6,'NY');
+CREATE TABLE t2 (id int NOT NULL, INDEX idx(id));
+INSERT INTO t2 VALUES (7), (5), (1), (3);
+
+SELECT id, st FROM t1 
+  WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
+SELECT id, st FROM t1 
+  WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
+    GROUP BY id;
+
+SELECT id, st FROM t1 
+  WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
+SELECT id, st FROM t1 
+  WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
+    GROUP BY id;
+
+DROP TABLE t1,t2;
+
 --echo End of 5.0 tests.

mysql-test/t/type_datetime.test

@@ -225,3 +225,24 @@ END;|
 DELIMITER ;|
 call test27759();
 drop procedure test27759;
+
+#
+# Bug#28208: Wrong result of a non-const STRING function with a const
+#            DATETIME function.
+#
+create table t1 (f1 date);
+insert into t1 values (curdate());
+select left(f1,10) = curdate() from t1;
+drop table t1;
+
+#
+# Bug#28261: Wrong DATETIME comparison result when the GET_USER_VAR function
+#            is involved.
+#
+create table t1(f1 date);
+insert into t1 values('01-01-01'),('02-02-02'),('01-01-01'),('02-02-02');
+set @bug28261='';
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+select if(@bug28261 = f1, '', @bug28261:= f1) from t1;
+drop table t1;

sql/item.cc

@@ -3503,7 +3503,8 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
           prev_subselect_item->const_item_cache= 0;
           set_field(*from_field);
           if (!last_checked_context->select_lex->having_fix_field &&
-              select->group_list.elements)
+              select->group_list.elements &&
+              (place == SELECT_LIST || place == IN_HAVING))
           {
             Item_outer_ref *rf;
             /*

sql/item_cmpfunc.cc

@@ -633,7 +633,13 @@ Arg_comparator::can_compare_as_dates(Item *a, Item *b, ulonglong *const_value)
 
   if (cmp_type != CMP_DATE_DFLT)
   {
-    if (cmp_type != CMP_DATE_WITH_DATE && str_arg->const_item())
+    /*
+      Do not cache GET_USER_VAR() function as its const_item() may return TRUE
+      for the current thread but it still may change during the execution.
+    */
+    if (cmp_type != CMP_DATE_WITH_DATE && str_arg->const_item() &&
+        (str_arg->type() != Item::FUNC_ITEM ||
+        ((Item_func*)str_arg)->functype() != Item_func::GUSERVAR_FUNC))
     {
       THD *thd= current_thd;
       ulonglong value;
@@ -661,7 +667,7 @@ int Arg_comparator::set_cmp_func(Item_bool_func2 *owner_arg,
                                         Item_result type)
 {
   enum enum_date_cmp_type cmp_type;
-  ulonglong const_value;
+  ulonglong const_value= (ulonglong)-1;
   a= a1;
   b= a2;
 
@@ -674,8 +680,7 @@ int Arg_comparator::set_cmp_func(Item_bool_func2 *owner_arg,
     a_cache= 0;
     b_cache= 0;
 
-    if (cmp_type != CMP_DATE_WITH_DATE &&
-        ((*b)->const_item() || (*a)->const_item()))
+    if (const_value != (ulonglong)-1)
     {
       Item_cache_int *cache= new Item_cache_int();
       /* Mark the cache as non-const to prevent re-caching. */
@@ -781,7 +786,12 @@ get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg,
       MYSQL_TYPE_DATE ? MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME;
     value= get_date_from_str(thd, str, t_type, warn_item->name, &error);
   }
-  if (item->const_item() && cache_arg)
+  /*
+    Do not cache GET_USER_VAR() function as its const_item() may return TRUE
+    for the current thread but it still may change during the execution.
+  */
+  if (item->const_item() && cache_arg && (item->type() != Item::FUNC_ITEM ||
+      ((Item_func*)item)->functype() != Item_func::GUSERVAR_FUNC))
   {
     Item_cache_int *cache= new Item_cache_int();
     /* Mark the cache as non-const to prevent re-caching. */

sql/item_sum.cc

@@ -3339,6 +3339,10 @@ String* Item_func_group_concat::val_str(String* str)
   DBUG_ASSERT(fixed == 1);
   if (null_value)
     return 0;
+  if (!result.length() && tree)
+    /* Tree is used for sorting as in ORDER BY */
+    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
+              left_root_right);
   if (count_cut_values && !warning)
   {
     /*
@@ -3350,11 +3354,6 @@ String* Item_func_group_concat::val_str(String* str)
                           ER_CUT_VALUE_GROUP_CONCAT,
                           ER(ER_CUT_VALUE_GROUP_CONCAT));
   }
-  if (result.length())
-    return &result;
-  if (tree)
-    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
-              left_root_right);
   return &result;
 }
 

sql/opt_sum.cc

@@ -206,12 +206,68 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
 
           if (!ref.key_length)
             error= table->file->index_first(table->record[0]);
-          else
-	    error= table->file->index_read(table->record[0],key_buff,
-					   ref.key_length,
-					   range_fl & NEAR_MIN ?
-					   HA_READ_AFTER_KEY :
-					   HA_READ_KEY_OR_NEXT);
+          else 
+          {
+            /*
+              Use index to replace MIN/MAX functions with their values
+              according to the following rules:
+           
+              1) Insert the minimum non-null values where the WHERE clause still
+                 matches, or
+              2) a NULL value if there are only NULL values for key_part_k.
+              3) Fail, producing a row of nulls
+
+              Implementation: Read the smallest value using the search key. If
+              the interval is open, read the next value after the search
+              key. If read fails, and we're looking for a MIN() value for a
+              nullable column, test if there is an exact match for the key.
+            */
+            if (!(range_fl & NEAR_MIN))
+              /* 
+                 Closed interval: Either The MIN argument is non-nullable, or
+                 we have a >= predicate for the MIN argument.
+              */
+              error= table->file->index_read(table->record[0], ref.key_buff,
+                                             ref.key_length, 
+                                             HA_READ_KEY_OR_NEXT);
+            else
+            {
+              /*
+                Open interval: There are two cases:
+                1) We have only MIN() and the argument column is nullable, or
+                2) there is a > predicate on it, nullability is irrelevant.
+                We need to scan the next bigger record first.
+              */
+              error= table->file->index_read(table->record[0], ref.key_buff, 
+                                             ref.key_length, HA_READ_AFTER_KEY);
+              /* 
+                 If the found record is outside the group formed by the search
+                 prefix, or there is no such record at all, check if all
+                 records in that group have NULL in the MIN argument
+                 column. If that is the case return that NULL.
+
+                 Check if case 1 from above holds. If it does, we should read
+                 the skipped tuple.
+              */
+              if (ref.key_buff[prefix_len] == 1 && 
+                  /* 
+                     Last keypart (i.e. the argument to MIN) is set to NULL by
+                     find_key_for_maxmin only if all other keyparts are bound
+                     to constants in a conjunction of equalities. Hence, we
+                     can detect this by checking only if the last keypart is
+                     NULL.
+                  */                     
+                  (error == HA_ERR_KEY_NOT_FOUND ||
+                   key_cmp_if_same(table, ref.key_buff, ref.key, prefix_len)))
+              {
+                DBUG_ASSERT(item_field->field->real_maybe_null());
+                error= table->file->index_read(table->record[0], ref.key_buff,
+                                               ref.key_length, 
+                                               HA_READ_KEY_EXACT);
+              }
+            }
+          }
+          /* Verify that the read tuple indeed matches the search key */
 	  if (!error && reckey_in_range(0, &ref, item_field->field, 
 			                conds, range_fl, prefix_len))
 	    error= HA_ERR_KEY_NOT_FOUND;
@@ -739,14 +795,24 @@ static bool find_key_for_maxmin(bool max_fl, TABLE_REF *ref,
           if (!max_fl && key_part_used == key_part_to_use && part->null_bit)
           {
             /*
-              SELECT MIN(key_part2) FROM t1 WHERE key_part1=const
-              If key_part2 may be NULL, then we want to find the first row
-              that is not null
+              The query is on this form:
+
+              SELECT MIN(key_part_k) 
+              FROM t1 
+              WHERE key_part_1 = const and ... and key_part_k-1 = const
+
+              If key_part_k is nullable, we want to find the first matching row
+              where key_part_k is not null. The key buffer is now {const, ...,
+              NULL}. This will be passed to the handler along with a flag
+              indicating open interval. If a tuple is read that does not match
+              these search criteria, an attempt will be made to read an exact
+              match for the key buffer.
             */
+            /* Set the first byte of key_part_k to 1, that means NULL */
             ref->key_buff[ref->key_length]= 1;
             ref->key_length+= part->store_length;
             *range_fl&= ~NO_MIN_RANGE;
-            *range_fl|= NEAR_MIN;                // > NULL
+            *range_fl|= NEAR_MIN; // Open interval
           }
           /*
             The following test is false when the key in the key tree is

sql/sql_select.cc

@@ -976,6 +976,12 @@ JOIN::optimize()
     }
   }
 
+  if (conds &&!outer_join && const_table_map != found_const_table_map && 
+      (select_options & SELECT_DESCRIBE) &&
+      select_lex->master_unit() == &thd->lex->unit) // upper level SELECT
+  {
+    conds=new Item_int((longlong) 0,1);	// Always false
+  }
   if (make_join_select(this, select, conds))
   {
     zero_result_cause=

sql/sql_union.cc

@@ -147,8 +147,16 @@ st_select_lex_unit::init_prepare_fake_select_lex(THD *thd_arg)
   fake_select_lex->table_list.link_in_list((byte *)&result_table_list,
 					   (byte **)
 					   &result_table_list.next_local);
-  fake_select_lex->context.table_list= fake_select_lex->context.first_name_resolution_table= 
+  fake_select_lex->context.table_list= 
+    fake_select_lex->context.first_name_resolution_table= 
     fake_select_lex->get_table_list();
+  if (!fake_select_lex->first_execution)
+  {
+    for (ORDER *order= (ORDER *) global_parameters->order_list.first;
+         order;
+         order= order->next)
+      order->item= &order->item_ptr;
+  }
   for (ORDER *order= (ORDER *)global_parameters->order_list.first;
        order;
        order=order->next)

strings/decimal.c

@@ -1083,7 +1083,11 @@ int decimal2longlong(decimal_t *from, longlong *to)
     x=x*DIG_BASE - *buf++;
     if (unlikely(y < (LONGLONG_MIN/DIG_BASE) || x > y))
     {
-      *to= from->sign ? y : -y;
+      /*
+        the decimal is bigger than any possible integer
+        return border integer depending on the sign
+      */
+      *to= from->sign ? LONGLONG_MIN : LONGLONG_MAX;
       return E_DEC_OVERFLOW;
     }
   }