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

1 files changed, 2 insertions, 1 deletions

diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index 782589f7d0f..3214c756bc7 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -147,10 +147,11 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *orig_table_list)
     if (!(derived_result= new select_union))
       DBUG_RETURN(TRUE); // out of memory
 
+    lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_DERIVED;
     // st_select_lex_unit::prepare correctly work for single select
     if ((res= unit->prepare(thd, derived_result, 0)))
       goto exit;
-
+    lex->context_analysis_only&= ~CONTEXT_ANALYSIS_ONLY_DERIVED;
     if ((res= check_duplicate_names(unit->types, 0)))
       goto exit;