BUG #16806: ALTER TABLE fails when creating new field not last in table

Moved some code to else path to avoid delete, create, delete, create scenarios.
Fixed up the partition info object for some cases where we move from default
partitioning in NDB to default partitioning using partitioning.


sql/sql_partition.cc:
  Added a new parameter for partition default handling
  This is to avoid calling get_no_parts on tables not yet
  created.
  Ensure that we don't reuse the old part_info object for
  any other operation than CREATE TABLE after reading up
  the frm file.
sql/sql_table.cc:
  Moved some code to else path to avoid delete, create, delete, create scenarios.
  Fixed up the partition info object for some cases where we move from default
  partitioning in NDB to default partitioning using partitioning.

sql/sql_partition.cc

@@ -199,13 +199,15 @@ bool is_name_in_list(char *name,
 */
 
 bool partition_default_handling(TABLE *table, partition_info *part_info,
+                                bool is_create_table_ind,
                                 const char *normalized_path)
 {
   DBUG_ENTER("partition_default_handling");
 
   if (part_info->use_default_no_partitions)
   {
-    if (table->file->get_no_parts(normalized_path, &part_info->no_parts))
+    if (!is_create_table_ind &&
+        table->file->get_no_parts(normalized_path, &part_info->no_parts))
     {
       DBUG_RETURN(TRUE);
     }
@@ -214,7 +216,8 @@ bool partition_default_handling(TABLE *table, partition_info *part_info,
            part_info->use_default_no_subpartitions)
   {
     uint no_parts;
-    if (table->file->get_no_parts(normalized_path, &no_parts))
+    if (!is_create_table_ind &&
+        (table->file->get_no_parts(normalized_path, &no_parts)))
     {
       DBUG_RETURN(TRUE);
     }
@@ -1737,9 +1740,12 @@ bool fix_partition_func(THD *thd, const char* name, TABLE *table,
   db_name= &db_name_string[home_dir_length];
   tables.db= db_name;
 
-  if (!is_create_table_ind)
+  if (!is_create_table_ind ||
+      (is_create_table_ind &&
+       thd->lex->sql_command != SQLCOM_CREATE_TABLE))
   {
     if (partition_default_handling(table, part_info,
+                                   is_create_table_ind,
                                    table->s->normalized_path.str))
     {
       DBUG_RETURN(TRUE);
@@ -3742,7 +3748,7 @@ bool mysql_unpack_partition(THD *thd, const uchar *part_buf,
   DBUG_PRINT("info", ("default engine = %d, default_db_type = %d",
              ha_legacy_type(part_info->default_engine_type),
              ha_legacy_type(default_db_type)));
-  if (is_create_table_ind)
+  if (is_create_table_ind && old_lex->sql_command == SQLCOM_CREATE_TABLE)
   {
     if (old_lex->like_name)
     {
@@ -3756,7 +3762,8 @@ bool mysql_unpack_partition(THD *thd, const uchar *part_buf,
       char *src_table= table_ident->table.str;
       char buf[FN_REFLEN];
       build_table_filename(buf, sizeof(buf), src_db, src_table, "");
-      if (partition_default_handling(table, part_info, buf))
+      if (partition_default_handling(table, part_info,
+                                     FALSE, buf))
       {
         result= TRUE;
         goto end;

sql/sql_table.cc

@@ -2130,15 +2130,6 @@ bool mysql_create_table_internal(THD *thd,
       goto err;
     part_info->part_info_string= part_syntax_buf;
     part_info->part_info_len= syntax_len;
-    if (create_info->db_type != engine_type)
-    {
-      delete file;
-      if (!(file= get_new_handler((TABLE_SHARE*) 0, thd->mem_root, engine_type)))
-      {
-        mem_alloc_error(sizeof(handler));
-        DBUG_RETURN(TRUE);
-      }
-    }
     if ((!(engine_type->partition_flags &&
            engine_type->partition_flags() & HA_CAN_PARTITION)) ||
         create_info->db_type == &partition_hton)
@@ -2155,6 +2146,43 @@ bool mysql_create_table_internal(THD *thd,
       {
         DBUG_RETURN(TRUE);
       }
+      /*
+        If we have default number of partitions or subpartitions we
+        might require to set-up the part_info object such that it
+        creates a proper .par file. The current part_info object is
+        only used to create the frm-file and .par-file.
+      */
+      if (part_info->use_default_no_partitions &&
+          part_info->no_parts &&
+          part_info->no_parts != file->get_default_no_partitions(0ULL))
+      {
+        uint i= 0;
+        bool first= TRUE;
+        List_iterator<partition_element> part_it(part_info->partitions);
+        do
+        {
+          partition_element *part_elem= part_it++;
+          if (!first)
+            part_elem->part_state= PART_TO_BE_DROPPED;
+          first= FALSE;
+        } while (++i < part_info->partitions.elements);
+      }
+      else if (part_info->is_sub_partitioned() &&
+               part_info->use_default_no_subpartitions &&
+               part_info->no_subparts &&
+               part_info->no_subparts != file->get_default_no_partitions(0ULL))
+      {
+        part_info->no_subparts= file->get_default_no_partitions(0ULL);
+      }
+    }
+    else if (create_info->db_type != engine_type)
+    {
+      delete file;
+      if (!(file= get_new_handler((TABLE_SHARE*) 0, thd->mem_root, engine_type)))
+      {
+        mem_alloc_error(sizeof(handler));
+        DBUG_RETURN(TRUE);
+      }
     }
   }
 #endif