Merge 5.2->5.3

- Re-commit Monty's merge, partially fixed by Igor and SergeyP, 
  but still broken

sql/handler.h

@@ -100,7 +100,10 @@
 #define HA_PRIMARY_KEY_IN_READ_INDEX (1 << 15)
 /*
   If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, it means that to position()
-  uses a primary key. Without primary key, we can't call position().
+  uses a primary key given by the record argument.
+  Without primary key, we can't call position().
+  If not set, the position is returned as the current rows position
+  regardless of what argument is given.
 */ 
 #define HA_PRIMARY_KEY_REQUIRED_FOR_POSITION (1 << 16) 
 #define HA_CAN_RTREEKEYS       (1 << 17)
@@ -1037,7 +1040,7 @@ typedef struct st_ha_create_information
   ulong avg_row_length;
   ulong used_fields;
   ulong key_block_size;
-  SQL_LIST merge_list;
+  SQL_I_List<TABLE_LIST> merge_list;
   handlerton *db_type;
   /**
     Row type of the table definition.
@@ -1448,6 +1451,7 @@ public:
   bool locked;
   bool implicit_emptied;                /* Can be !=0 only if HEAP */
   bool mark_trx_done;
+  bool cloned;                          /* 1 if this was created with clone */
   const COND *pushed_cond;
   Item *pushed_idx_cond;
   uint pushed_idx_cond_keyno;  /* The index which the above condition is for */
@@ -1494,7 +1498,7 @@ public:
     key_used_on_scan(MAX_KEY), active_index(MAX_KEY),
     ref_length(sizeof(my_off_t)),
     ft_handler(0), inited(NONE),
-    locked(FALSE), implicit_emptied(FALSE), mark_trx_done(FALSE), 
+    locked(FALSE), implicit_emptied(FALSE), mark_trx_done(FALSE), cloned(0),
     pushed_cond(0), pushed_idx_cond(NULL),
     pushed_idx_cond_keyno(MAX_KEY),
     next_insert_id(0), insert_id_for_cur_row(0),
@@ -1537,7 +1541,7 @@ public:
   }
   /* This is called after index_init() if we need to do a index scan */
   virtual int prepare_index_scan() { return 0; }
-  int ha_rnd_init(bool scan)
+  int ha_rnd_init(bool scan) __attribute__ ((warn_unused_result))
   {
     int result;
     DBUG_ENTER("ha_rnd_init");
@@ -1552,6 +1556,7 @@ public:
     inited=NONE;
     DBUG_RETURN(rnd_end());
   }
+  int ha_rnd_init_with_error(bool scan) __attribute__ ((warn_unused_result));
   int ha_reset();
   /* Tell handler (not storage engine) this is start of a new statement */
   void ha_start_of_new_statement()
@@ -1591,10 +1596,10 @@ public:
     estimation_rows_to_insert= rows;
     start_bulk_insert(rows);
   }
-  int ha_end_bulk_insert(bool abort)
+  int ha_end_bulk_insert()
   {
     estimation_rows_to_insert= 0;
-    return end_bulk_insert(abort);
+    return end_bulk_insert();
   }
   int ha_bulk_update_row(const uchar *old_data, uchar *new_data,
                          uint *dup_key_found);
@@ -1826,10 +1831,9 @@ private:
   virtual int rnd_next(uchar *buf)=0;
   virtual int rnd_pos(uchar * buf, uchar *pos)=0;
   /**
-    One has to use this method when to find
-    random position by record as the plain
-    position() call doesn't work for some
-    handlers for random position.
+    This function only works for handlers having
+    HA_PRIMARY_KEY_REQUIRED_FOR_POSITION set.
+    It will return the row with the PK given in the record argument.
   */
   virtual int rnd_pos_by_record(uchar *record)
   {
@@ -1860,6 +1864,12 @@ public:
   virtual ha_rows records_in_range(uint inx, key_range *min_key,
                                    key_range *max_key)
     { return (ha_rows) 10; }
+  /*
+    If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, then it sets ref
+    (reference to the row, aka position, with the primary key given in
+    the record).
+    Otherwise it set ref to the current row.
+  */
   virtual void position(const uchar *record)=0;
   virtual int info(uint)=0; // see my_base.h for full description
   virtual void get_dynamic_partition_info(PARTITION_INFO *stat_info,
@@ -2278,7 +2288,7 @@ private:
   virtual int repair(THD* thd, HA_CHECK_OPT* check_opt)
   { return HA_ADMIN_NOT_IMPLEMENTED; }
   virtual void start_bulk_insert(ha_rows rows) {}
-  virtual int end_bulk_insert(bool abort) { return 0; }
+  virtual int end_bulk_insert() { return 0; }
   virtual int index_read(uchar * buf, const uchar * key, uint key_len,
                          enum ha_rkey_function find_flag)
    { return  HA_ERR_WRONG_COMMAND; }