BUG#16613004 PARTITIONING DDL, CRASH IN FIELD_VARSTRING::CMP_MAX

Problem :
---------
The specific issue reported in this bug is with range/list column
value that is allocated and initialized by evaluating partition
expression(item tree) during execution. After evaluation the range
list value is marked fixed [part_column_list_val]. During next
execution, we don't re-evaluate the expression and use the old value
since it is marked fixed.

Solution :
----------
One way to solve the issue is to mark all column values as not fixed
during clone so that the expression is always re-evaluated once we
attempt partition_info::fix_column_value_functions() after cloning
the part_info object during execution of DDL on partitioned table.

Reviewed-by: Jimmy Yang <[email protected]>
Reviewed-by: Mattias Jonsson <[email protected]>

RB: 9424

Author: Debarun Banerjee

sql/partition_info.cc

@@ -31,7 +31,7 @@
 #include "ha_partition.h"
 
 
-partition_info *partition_info::get_clone()
+partition_info *partition_info::get_clone(bool reset /* = false */)
 {
   if (!this)
     return 0;
@@ -57,6 +57,26 @@ partition_info *partition_info::get_clone()
       return NULL;
     }
     memcpy(part_clone, part, sizeof(partition_element));
+
+    /*
+      Mark that RANGE and LIST values needs to be fixed so that we don't
+      use old values. fix_column_value_functions would evaluate the values
+      from Item expression.
+    */
+    if (reset)
+    {
+      clone->defined_max_value = false;
+      List_iterator<part_elem_value> list_it(part_clone->list_val_list);
+      while (part_elem_value *list_value= list_it++)
+      {
+        part_column_list_val *col_val= list_value->col_val_array;
+        for (uint i= 0; i < num_columns; col_val++, i++)
+        {
+          col_val->fixed= 0;
+        }
+      }
+    }
+
     part_clone->subpartitions.empty();
     while ((subpart= (subpart_it++)))
     {

sql/partition_info.h

@@ -1,7 +1,7 @@
 #ifndef PARTITION_INFO_INCLUDED
 #define PARTITION_INFO_INCLUDED
 
-/* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -265,7 +265,7 @@ class partition_info : public Sql_alloc
   }
   ~partition_info() {}
 
-  partition_info *get_clone();
+  partition_info *get_clone(bool reset = false);
   /* Answers the question if subpartitioning is used for a certain table */
   bool is_sub_partitioned()
   {

sql/sql_parse.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -2428,7 +2428,7 @@ case SQLCOM_PREPARE:
 #ifdef WITH_PARTITION_STORAGE_ENGINE
     {
       partition_info *part_info= thd->lex->part_info;
-      if (part_info && !(part_info= thd->lex->part_info->get_clone()))
+      if (part_info && !(part_info= thd->lex->part_info->get_clone(true)))
       {
         res= -1;
         goto end_with_restore_list;

sql/sql_partition.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -4718,7 +4718,7 @@ uint prep_alter_part_table(THD *thd, TABLE *table, Alter_info *alter_info,
   thd->work_part_info= thd->lex->part_info;
 
   if (thd->work_part_info &&
-      !(thd->work_part_info= thd->lex->part_info->get_clone()))
+      !(thd->work_part_info= thd->lex->part_info->get_clone(true)))
     DBUG_RETURN(TRUE);
 
   /* ALTER_ADMIN_PARTITION is handled in mysql_admin_table */