ndb - bug#22838

    when doing create unique index which mysql will silently converts to PK, ndb is not informed
    so table will be useless.
  
    change so that we never do online add index wo/ primary key.
    this is not good, but it's better than a useless table

sql/ha_ndbcluster.cc

@@ -10152,6 +10152,8 @@ bool ha_ndbcluster::check_if_incompatible_data(HA_CREATE_INFO *info,
     DBUG_RETURN(COMPATIBLE_DATA_NO);
   }
 
+  int pk= 0;
+  int ai= 0;
   for (i= 0; i < table->s->fields; i++) 
   {
     Field *field= table->field[i];
@@ -10167,10 +10169,33 @@ bool ha_ndbcluster::check_if_incompatible_data(HA_CREATE_INFO *info,
       DBUG_PRINT("info", ("add/drop index not supported for disk stored column"));
       DBUG_RETURN(COMPATIBLE_DATA_NO);
     }
+    
+    if (field->flags & PRI_KEY_FLAG)
+      pk=1;
+    if (field->flags & FIELD_IN_ADD_INDEX)
+      ai=1;
   }
   if (table_changes != IS_EQUAL_YES)
     DBUG_RETURN(COMPATIBLE_DATA_NO);
   
+  /**
+   * Changing from/to primary key
+   *
+   * This is _not_ correct, but check_if_incompatible_data-interface
+   *   doesnt give more info, so I guess that we can't do any
+   *   online add index if not using primary key
+   *
+   *   This as mysql will handle a unique not null index as primary 
+   *     even wo/ user specifiying it... :-(
+   *   
+   */
+  if ((table_share->primary_key == MAX_KEY && pk) ||
+      (table_share->primary_key != MAX_KEY && !pk) ||
+      (table_share->primary_key == MAX_KEY && !pk && ai))
+  {
+    DBUG_RETURN(COMPATIBLE_DATA_NO);
+  }
+  
   /* Check that auto_increment value was not changed */
   if ((info->used_fields & HA_CREATE_USED_AUTO) &&
       info->auto_increment_value != 0)