Bug #16051817 GOT ERROR 124 FROM STORAGE ENGINE

               ON DELETE FROM A PARTITIONED TABLE

PROBLEM
-------

The user first disables all the non unique indexes
in the table and then rebuilds one partition.
During rebuild the indexes on that particular
partition are enabled. Now when we give a query 
the optimizer is unaware that on one partition 
indexes are enabled and if the optimizer selects
that index,myisam thinks that the index is not 
active and gives an error.

FIX
---

Before rebuilding a partition check whether non
unique indexes are disabled on the partitons.
If they are disabled then after rebuild disable
the index on the partition. 

[Approved by Mattiasj #rb3469]

sql/ha_partition.cc

@@ -1337,7 +1337,8 @@ bool ha_partition::is_crashed() const
 int ha_partition::prepare_new_partition(TABLE *tbl,
                                         HA_CREATE_INFO *create_info,
                                         handler *file, const char *part_name,
-                                        partition_element *p_elem)
+                                        partition_element *p_elem,
+                                        uint disable_non_uniq_indexes)
 {
   int error;
   DBUG_ENTER("prepare_new_partition");
@@ -1362,6 +1363,7 @@ int ha_partition::prepare_new_partition(TABLE *tbl,
   if ((error= file->ha_open(tbl, part_name, m_mode, m_open_test_lock)))
     goto error_open;
   DBUG_PRINT("info", ("partition %s opened", part_name));
+
   /*
     Note: if you plan to add another call that may return failure,
     better to do it before external_lock() as cleanup_new_partition()
@@ -1372,6 +1374,9 @@ int ha_partition::prepare_new_partition(TABLE *tbl,
     goto error_external_lock;
   DBUG_PRINT("info", ("partition %s external locked", part_name));
 
+  if (disable_non_uniq_indexes)
+    file->ha_disable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE);
+
   DBUG_RETURN(0);
 error_external_lock:
   (void) file->close();
@@ -1649,6 +1654,14 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
       on them to prepare them for copy phase and also for later close
       calls
   */
+
+  /*
+     Before creating new partitions check whether indexes are disabled
+     in the  partitions.
+  */
+
+  uint disable_non_uniq_indexes = indexes_are_disabled();
+
   i= 0;
   part_count= 0;
   part_it.rewind();
@@ -1683,11 +1696,13 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
           if ((error= prepare_new_partition(table, create_info,
                                             new_file_array[part],
                                             (const char *)part_name_buff,
-                                            sub_elem)))
+                                            sub_elem,
+                                            disable_non_uniq_indexes)))
           {
             cleanup_new_partition(part_count);
             DBUG_RETURN(error);
           }
+
           m_added_file[part_count++]= new_file_array[part];
         } while (++j < num_subparts);
       }
@@ -1700,11 +1715,13 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
         if ((error= prepare_new_partition(table, create_info,
                                           new_file_array[i],
                                           (const char *)part_name_buff,
-                                          part_elem)))
+                                          part_elem,
+                                          disable_non_uniq_indexes)))
         {
           cleanup_new_partition(part_count);
           DBUG_RETURN(error);
         }
+
         m_added_file[part_count++]= new_file_array[i];
       }
     }

sql/ha_partition.h

@@ -270,7 +270,8 @@ class ha_partition :public handler
   void cleanup_new_partition(uint part_count);
   int prepare_new_partition(TABLE *table, HA_CREATE_INFO *create_info,
                             handler *file, const char *part_name,
-                            partition_element *p_elem);
+                            partition_element *p_elem,
+                            uint disable_non_uniq_indexes);
   /*
     delete_table, rename_table and create uses very similar logic which
     is packed into this routine.