Bug#20548 Events: crash if InnoDB, multiple events, busy procedures, partitions

setup 'share' struct for all partiton file elements. It's neccessary because we use
m_file[0]->update_create_info(create_info) during ha_partition::update_create_info
and 'share' for m_file[0] should be valid


sql/ha_partition.h:
  Bug#20548 Events: crash if InnoDB, multiple events, busy procedures, partitions
sql/handler.h:
  Bug#20548 Events: crash if InnoDB, multiple events, busy procedures, partitions

sql/ha_partition.cc

@@ -1579,6 +1579,17 @@ void ha_partition::update_create_info(HA_CREATE_INFO *create_info)
 }
 
 
+void ha_partition::change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
+{
+  handler **file_array= m_file;
+  table= table_arg;
+  table_share= share;
+  do
+  {
+    (*file_array)->change_table_ptr(table_arg, share);
+  } while (*(++file_array));
+}
+
 /*
   Change comments specific to handler
 

sql/ha_partition.h

@@ -199,6 +199,7 @@ class ha_partition :public handler
     *no_parts= m_tot_parts;
     DBUG_RETURN(0);
   }
+  virtual void change_table_ptr(TABLE *table_arg, TABLE_SHARE *share);
 private:
   int prepare_for_delete();
   int copy_partitions(ulonglong *copied, ulonglong *deleted);

sql/handler.h

@@ -983,7 +983,7 @@ class handler :public Sql_alloc
   virtual void print_error(int error, myf errflag);
   virtual bool get_error_message(int error, String *buf);
   uint get_dup_key(int error);
-  void change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
+  virtual void change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
   {
     table= table_arg;
     table_share= share;