Merge 4.1->5.0

client/mysqlimport.c:
  Auto merged
configure.in:
  Auto merged
include/my_global.h:
  Auto merged
mysql-test/r/connect.result:
  Auto merged
mysql-test/r/func_gconcat.result:
  Auto merged
mysql-test/t/connect.test:
  Auto merged
mysql-test/t/func_gconcat.test:
  Auto merged
ndb/src/kernel/blocks/backup/Backup.cpp:
  Auto merged
ndb/src/kernel/blocks/backup/Backup.hpp:
  Auto merged
ndb/src/kernel/main.cpp:
  Auto merged
ndb/src/mgmsrv/MgmtSrvr.cpp:
  Auto merged
ndb/src/mgmsrv/MgmtSrvr.hpp:
  Auto merged
ndb/src/ndbapi/Makefile.am:
  Auto merged
ndb/test/src/NdbBackup.cpp:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/item_cmpfunc.h:
  Auto merged
sql/sql_select.cc:
  Auto merged

5 files changed, 23 insertions, 8 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 3bbc78f5db8..09a0fa8c357 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -910,7 +910,7 @@ public:
     else
     {
       args[0]->update_used_tables();
-      if (!(used_tables_cache=args[0]->used_tables()))
+      if ((const_item_cache= !(used_tables_cache= args[0]->used_tables())))
       {
 	/* Remember if the value is always NULL or never NULL */
 	cached_value= (longlong) args[0]->is_null();
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 17d82e3fc98..4f991615bfa 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -2740,7 +2740,9 @@ int dump_leaf_key(byte* key, element_count count __attribute__((unused)),
   String *result= &item->result;
   Item **arg= item->args, **arg_end= item->args + item->arg_count_field;
 
-  if (result->length())
+  if (item->no_appended)
+    item->no_appended= FALSE;
+  else
     result->append(*item->separator);
 
   tmp.length(0);
@@ -2925,6 +2927,7 @@ void Item_func_group_concat::clear()
   result.copy();
   null_value= TRUE;
   warning_for_row= FALSE;
+  no_appended= TRUE;
   if (tree)
     reset_tree(tree);
   /* No need to reset the table as we never call write_row */
diff --git a/sql/item_sum.h b/sql/item_sum.h
index 0da9178eabf..8c31cc5952c 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -898,6 +898,7 @@ class Item_func_group_concat : public Item_sum
                            element_count count __attribute__((unused)),
 			   Item_func_group_concat *group_concat_item);
 
+  bool no_appended;
 public:
   Item_func_group_concat(Name_resolution_context *context_arg,
                          bool is_distinct, List<Item> *is_select,
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 2ff0413e05e..4ed8d61a2be 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -377,14 +377,14 @@ void THD::cleanup(void)
   mysql_ha_flush(this, (TABLE_LIST*) 0,
                  MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL);
   hash_free(&handler_tables_hash);
+  delete_dynamic(&user_var_events);
+  hash_free(&user_vars);
   close_temporary_tables(this);
   my_free((char*) variables.time_format, MYF(MY_ALLOW_ZERO_PTR));
   my_free((char*) variables.date_format, MYF(MY_ALLOW_ZERO_PTR));
   my_free((char*) variables.datetime_format, MYF(MY_ALLOW_ZERO_PTR));
-  delete_dynamic(&user_var_events);
-  hash_free(&user_vars);
   sp_cache_clear(&sp_proc_cache);
-  sp_cache_clear(&sp_func_cache);
+  sp_cache_clear(&sp_func_cache); /*psergey: move to ~THD? */
   if (global_read_lock)
     unlock_global_read_lock(this);
   if (ull)
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index bf06599b25e..28afec2f688 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -13043,6 +13043,8 @@ void free_underlaid_joins(THD *thd, SELECT_LEX *select)
     The function replaces occurrences of group by fields in expr
     by ref objects for these fields unless they are under aggregate
     functions.
+    The function also corrects value of the the maybe_null attribute
+    for the items of all subexpressions containing group by fields.
 
   IMPLEMENTATION
     The function recursively traverses the tree of the expr expression,
@@ -13053,6 +13055,9 @@ void free_underlaid_joins(THD *thd, SELECT_LEX *select)
     This substitution is needed GROUP BY queries with ROLLUP if
     SELECT list contains expressions over group by attributes.
 
+  TODO: Some functions are not null-preserving. For those functions
+    updating of the maybe_null attribute is an overkill. 
+
   EXAMPLES
     SELECT a+1 FROM t1 GROUP BY a WITH ROLLUP
     SELECT SUM(a)+a FROM t1 GROUP BY a WITH ROLLUP 
@@ -13074,6 +13079,7 @@ static bool change_group_ref(THD *thd, Item_func *expr, ORDER *group_list,
          arg != arg_end; arg++)
     {
       Item *item= *arg;
+      bool arg_changed= FALSE;
       if (item->type() == Item::FIELD_ITEM || item->type() == Item::REF_ITEM)
       {
         ORDER *group_tmp;
@@ -13086,15 +13092,20 @@ static bool change_group_ref(THD *thd, Item_func *expr, ORDER *group_list,
                                         item->name)))
               return 1;                                 // fatal_error is set
             thd->change_item_tree(arg, new_item);
-            *changed= TRUE;
+            arg_changed= TRUE;
           }
         }
       }
       else if (item->type() == Item::FUNC_ITEM)
       {
-        if (change_group_ref(thd, (Item_func *) item, group_list, changed))
+        if (change_group_ref(thd, (Item_func *) item, group_list, &arg_changed))
           return 1;
       }
+      if (arg_changed)
+      {
+        expr->maybe_null= 1;
+        *changed= TRUE;
+      }
     }
   }
   return 0;
@@ -13157,7 +13168,7 @@ bool JOIN::rollup_init()
     }
     if (item->type() == Item::FUNC_ITEM)
     {
-      bool changed= 0;
+      bool changed= FALSE;
       if (change_group_ref(thd, (Item_func *) item, group_list, &changed))
         return 1;
       /*