BUG#26117 "index_merge sort-union over partitioned table crashes"

Before the fix: 
  ha_partition objects had ha_partition::m_part_info==NULL and that caused
  crash
After: 
- The new ha_partition::clone() function makes the clones use parent's
  m_part_info value.
- The parent ha_partition object remains responsible for deallocation of
  m_part_info.

mysql-test/r/partition_innodb.result

@@ -74,3 +74,57 @@ t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1 /*!50100 PARTITION BY LIST (a) (PARTITION p0 VALUES IN (0) ENGINE = InnoDB) */
 drop table t1;
+create table t1
+(
+id int unsigned auto_increment,
+time datetime not null,
+first_name varchar(40),
+last_name varchar(50),
+primary key (id, time),
+index first_index (first_name),
+index last_index (last_name)	
+) engine=Innodb partition by range (to_days(time)) (
+partition p1 values less than (to_days('2007-02-07')),
+partition p2 values less than (to_days('2007-02-08')),
+partition p3 values less than MAXVALUE
+);
+insert into t1 (time, first_name, last_name) values ('2007-02-07', 'Q', 'Robert'),
+('2007-02-07', 'Mark', 'Nate'), ('2007-02-07', 'Nate', 'Oscar'),
+('2007-02-07', 'Zack', 'Alice'), ('2007-02-07', 'Jack', 'Kathy'),
+('2007-02-06', 'Alice', 'Alice'), ('2007-02-06', 'Brian', 'Charles'),
+('2007-02-06', 'Charles', 'David'), ('2007-02-06', 'David', 'Eric'),
+('2007-02-07', 'Hector', 'Isaac'), ('2007-02-07', 'Oscar', 'Patricia'),
+('2007-02-07', 'Patricia', 'Q'), ('2007-02-07', 'X', 'Yuri'),
+('2007-02-07', 'Robert', 'Shawn'), ('2007-02-07', 'Kathy', 'Lois'),
+('2007-02-07', 'Eric', 'Francis'), ('2007-02-06', 'Shawn', 'Theron'),
+('2007-02-06', 'U', 'Vincent'), ('2007-02-06', 'Francis', 'George'),
+('2007-02-06', 'George', 'Hector'), ('2007-02-06', 'Vincent', 'Walter'),
+('2007-02-06', 'Walter', 'X'), ('2007-02-07', 'Lois', 'Mark'),
+('2007-02-07', 'Yuri', 'Zack'), ('2007-02-07', 'Isaac', 'Jack'),
+('2007-02-07', 'Sharon', 'Mark'), ('2007-02-07', 'Michael', 'Michelle'),
+('2007-02-07', 'Derick', 'Nathan'), ('2007-02-07', 'Peter', 'Xavier'),
+('2007-02-07', 'Fred', 'Harold'), ('2007-02-07', 'Katherine', 'Lisa'),
+('2007-02-07', 'Tom', 'Rina'), ('2007-02-07', 'Jerry', 'Victor'),
+('2007-02-07', 'Alexander', 'Terry'), ('2007-02-07', 'Justin', 'John'),
+('2007-02-07', 'Greg', 'Ernest'), ('2007-02-07', 'Robert', 'Q'),
+('2007-02-07', 'Nate', 'Mark'), ('2007-02-07', 'Oscar', 'Nate'),
+('2007-02-07', 'Alice', 'Zack'), ('2007-02-07', 'Kathy', 'Jack'),
+('2007-02-06', 'Alice', 'Alice'), ('2007-02-06', 'Charles', 'Brian'),
+('2007-02-06', 'David', 'Charles'), ('2007-02-06', 'Eric', 'David'),
+('2007-02-07', 'Isaac', 'Hector'), ('2007-02-07', 'Patricia', 'Oscar'),
+('2007-02-07', 'Q', 'Patricia'), ('2007-02-07', 'Yuri', 'X'),
+('2007-02-07', 'Shawn', 'Robert'), ('2007-02-07', 'Lois', 'Kathy'),
+('2007-02-07', 'Francis', 'Eric'), ('2007-02-06', 'Theron', 'Shawn'),
+('2007-02-06', 'Vincent', 'U'), ('2007-02-06', 'George', 'Francis'),
+('2007-02-06', 'Hector', 'George'), ('2007-02-06', 'Walter', 'Vincent'),
+('2007-02-06', 'X', 'Walter'), ('2007-02-07', 'Mark', 'Lois'),
+('2007-02-07', 'Zack', 'Yuri'), ('2007-02-07', 'Jack', 'Isaac'),
+('2007-02-07', 'Mark', 'Sharon'), ('2007-02-07', 'Michelle', 'Michael'),
+('2007-02-07', 'Nathan', 'Derick'), ('2007-02-07', 'Xavier', 'Peter'),
+('2007-02-07', 'Harold', 'Fred'), ('2007-02-07', 'Lisa', 'Katherine'),
+('2007-02-07', 'Rina', 'Tom'), ('2007-02-07', 'Victor', 'Jerry'),
+('2007-02-07', 'Terry', 'Alexander'), ('2007-02-07', 'John', 'Justin'),
+('2007-02-07', 'Ernest', 'Greg');
+SELECT * FROM t1 WHERE first_name='Andy' OR last_name='Jake';
+id	time	first_name	last_name
+drop table t1;

mysql-test/t/partition_innodb.test

@@ -75,4 +75,62 @@ alter table t1 engine = x;
 show create table t1;
 drop table t1;
 
+# BUG#26117: index_merge sort-union over partitioned table crashes
+
+create table t1
+(
+  id int unsigned auto_increment,
+  time datetime not null,
+  first_name varchar(40),
+  last_name varchar(50),
+  primary key (id, time),
+  index first_index (first_name),
+  index last_index (last_name)	
+) engine=Innodb partition by range (to_days(time)) (
+  partition p1 values less than (to_days('2007-02-07')),
+  partition p2 values less than (to_days('2007-02-08')),
+  partition p3 values less than MAXVALUE
+);
+
+insert into t1 (time, first_name, last_name) values ('2007-02-07', 'Q', 'Robert'),
+('2007-02-07', 'Mark', 'Nate'), ('2007-02-07', 'Nate', 'Oscar'),
+('2007-02-07', 'Zack', 'Alice'), ('2007-02-07', 'Jack', 'Kathy'),
+('2007-02-06', 'Alice', 'Alice'), ('2007-02-06', 'Brian', 'Charles'),
+('2007-02-06', 'Charles', 'David'), ('2007-02-06', 'David', 'Eric'),
+('2007-02-07', 'Hector', 'Isaac'), ('2007-02-07', 'Oscar', 'Patricia'),
+('2007-02-07', 'Patricia', 'Q'), ('2007-02-07', 'X', 'Yuri'),
+('2007-02-07', 'Robert', 'Shawn'), ('2007-02-07', 'Kathy', 'Lois'),
+('2007-02-07', 'Eric', 'Francis'), ('2007-02-06', 'Shawn', 'Theron'),
+('2007-02-06', 'U', 'Vincent'), ('2007-02-06', 'Francis', 'George'),
+('2007-02-06', 'George', 'Hector'), ('2007-02-06', 'Vincent', 'Walter'),
+('2007-02-06', 'Walter', 'X'), ('2007-02-07', 'Lois', 'Mark'),
+('2007-02-07', 'Yuri', 'Zack'), ('2007-02-07', 'Isaac', 'Jack'),
+('2007-02-07', 'Sharon', 'Mark'), ('2007-02-07', 'Michael', 'Michelle'),
+('2007-02-07', 'Derick', 'Nathan'), ('2007-02-07', 'Peter', 'Xavier'),
+('2007-02-07', 'Fred', 'Harold'), ('2007-02-07', 'Katherine', 'Lisa'),
+('2007-02-07', 'Tom', 'Rina'), ('2007-02-07', 'Jerry', 'Victor'),
+('2007-02-07', 'Alexander', 'Terry'), ('2007-02-07', 'Justin', 'John'),
+('2007-02-07', 'Greg', 'Ernest'), ('2007-02-07', 'Robert', 'Q'),
+('2007-02-07', 'Nate', 'Mark'), ('2007-02-07', 'Oscar', 'Nate'),
+('2007-02-07', 'Alice', 'Zack'), ('2007-02-07', 'Kathy', 'Jack'),
+('2007-02-06', 'Alice', 'Alice'), ('2007-02-06', 'Charles', 'Brian'),
+('2007-02-06', 'David', 'Charles'), ('2007-02-06', 'Eric', 'David'),
+('2007-02-07', 'Isaac', 'Hector'), ('2007-02-07', 'Patricia', 'Oscar'),
+('2007-02-07', 'Q', 'Patricia'), ('2007-02-07', 'Yuri', 'X'),
+('2007-02-07', 'Shawn', 'Robert'), ('2007-02-07', 'Lois', 'Kathy'),
+('2007-02-07', 'Francis', 'Eric'), ('2007-02-06', 'Theron', 'Shawn'),
+('2007-02-06', 'Vincent', 'U'), ('2007-02-06', 'George', 'Francis'),
+('2007-02-06', 'Hector', 'George'), ('2007-02-06', 'Walter', 'Vincent'),
+('2007-02-06', 'X', 'Walter'), ('2007-02-07', 'Mark', 'Lois'),
+('2007-02-07', 'Zack', 'Yuri'), ('2007-02-07', 'Jack', 'Isaac'),
+('2007-02-07', 'Mark', 'Sharon'), ('2007-02-07', 'Michelle', 'Michael'),
+('2007-02-07', 'Nathan', 'Derick'), ('2007-02-07', 'Xavier', 'Peter'),
+('2007-02-07', 'Harold', 'Fred'), ('2007-02-07', 'Lisa', 'Katherine'),
+('2007-02-07', 'Rina', 'Tom'), ('2007-02-07', 'Victor', 'Jerry'),
+('2007-02-07', 'Terry', 'Alexander'), ('2007-02-07', 'John', 'Justin'),
+('2007-02-07', 'Ernest', 'Greg');
+
+SELECT * FROM t1 WHERE first_name='Andy' OR last_name='Jake';
+
+drop table t1;
 

sql/ha_partition.cc

@@ -158,7 +158,7 @@ static uint alter_table_flags(uint flags __attribute__((unused)))
 
 ha_partition::ha_partition(handlerton *hton, TABLE_SHARE *share)
   :handler(hton, share), m_part_info(NULL), m_create_handler(FALSE),
-   m_is_sub_partitioned(0)
+   m_is_sub_partitioned(0), is_clone(FALSE)
 {
   DBUG_ENTER("ha_partition::ha_partition(table)");
   init_handler_variables();
@@ -180,8 +180,7 @@ ha_partition::ha_partition(handlerton *hton, TABLE_SHARE *share)
 ha_partition::ha_partition(handlerton *hton, partition_info *part_info)
   :handler(hton, NULL), m_part_info(part_info),
    m_create_handler(TRUE),
-   m_is_sub_partitioned(m_part_info->is_sub_partitioned())
-
+   m_is_sub_partitioned(m_part_info->is_sub_partitioned()), is_clone(FALSE)
 {
   DBUG_ENTER("ha_partition::ha_partition(part_info)");
   init_handler_variables();
@@ -2320,6 +2319,19 @@ err_handler:
   DBUG_RETURN(error);
 }
 
+handler *ha_partition::clone(MEM_ROOT *mem_root)
+{
+  handler *new_handler= get_new_handler(table->s, mem_root, table->s->db_type);
+  ((ha_partition*)new_handler)->m_part_info= m_part_info;
+  ((ha_partition*)new_handler)->is_clone= TRUE;
+  if (new_handler && !new_handler->ha_open(table,
+                                           table->s->normalized_path.str,
+                                           table->db_stat,
+                                           HA_OPEN_IGNORE_IF_LOCKED))
+    return new_handler;
+  return NULL;
+}
+
 
 /*
   Close handler object
@@ -2346,7 +2358,8 @@ int ha_partition::close(void)
   DBUG_ENTER("ha_partition::close");
 
   delete_queue(&m_queue);
-  bitmap_free(&(m_part_info->used_partitions));
+  if (!is_clone)
+    bitmap_free(&(m_part_info->used_partitions));
   file= m_file;
 
 repeat:

sql/ha_partition.h

@@ -132,7 +132,13 @@ private:
   THR_LOCK_DATA lock;                   /* MySQL lock */
   PARTITION_SHARE *share;               /* Shared lock info */
 
+  /* 
+    TRUE <=> this object was created with ha_partition::clone and doesn't
+    "own" the m_part_info structure.
+  */
+  bool is_clone;
 public:
+  handler *clone(MEM_ROOT *mem_root);
   virtual void set_part_info(partition_info *part_info)
   {
      m_part_info= part_info;