Merge with MySQL 5.1.55

- Fixed some issues with partitions and connection_string, which also fixed lp:716890 "Pre- and post-recovery crash in Aria"
- Fixed wrong assert in Aria

Now need to merge with latest xtradb before pushing 

sql/ha_partition.cc:
  Ensure that m_ordered_rec_buffer is not freed before close.
sql/mysqld.cc:
  Changed to use opt_stack_trace instead of opt_pstack.
  Removed references to pstack
sql/partition_element.h:
  Ensure that connect_string is initialized
storage/maria/ma_key_recover.c:
  Fixed wrong assert

sql/sql_base.cc

@@ -1,4 +1,4 @@
-/* Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc.
+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates.
 
    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
@@ -3002,6 +3002,11 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
   table->insert_values= 0;
   table->fulltext_searched= 0;
   table->file->ft_handler= 0;
+  /*
+    Check that there is no reference to a condtion from an earlier query
+    (cf. Bug#58553). 
+  */
+  DBUG_ASSERT(table->file->pushed_cond == NULL);
   table->reginfo.impossible_range= 0;
   /* Catch wrong handling of the auto_increment_field_not_null. */
   DBUG_ASSERT(!table->auto_increment_field_not_null);
@@ -5982,6 +5987,8 @@ find_field_in_natural_join(THD *thd, TABLE_LIST *table_ref, const char *name,
 /*
   Find field by name in a base table or a view with temp table algorithm.
 
+  The caller is expected to check column-level privileges.
+
   SYNOPSIS
     find_field_in_table()
     thd				thread handler
@@ -6089,6 +6096,8 @@ find_field_in_table(THD *thd, TABLE *table, const char *name, uint length,
     This procedure detects the type of the table reference 'table_list'
     and calls the corresponding search routine.
 
+    The routine checks column-level privieleges for the found field.
+
   RETURN
     0			field is not found
     view_ref_found	found value in VIEW (real result is in *ref)
@@ -6362,8 +6371,16 @@ find_field_in_tables(THD *thd, Item_ident *item,
       when table_ref->field_translation != NULL.
       */
     if (table_ref->table && !table_ref->view)
+    {
       found= find_field_in_table(thd, table_ref->table, name, length,
                                  TRUE, &(item->cached_field_index));
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+      /* Check if there are sufficient access rights to the found field. */
+      if (found && check_privileges &&
+          check_column_grant_in_table_ref(thd, table_ref, name, length))
+        found= WRONG_GRANT;
+#endif
+    }
     else
       found= find_field_in_table_ref(thd, table_ref, name, length, item->name,
                                      NULL, NULL, ref, check_privileges,