Fixed nested conditions for condition pushdown to storage engine

sql/ha_ndbcluster.h

@@ -64,7 +64,8 @@ typedef struct st_ndbcluster_share {
 typedef enum ndb_item_type {
   NDB_VALUE = 0,   // Qualified more with Item::Type
   NDB_FIELD = 1,   // Qualified from table definition
-  NDB_FUNCTION = 2 // Qualified from Item_func::Functype
+  NDB_FUNCTION = 2,// Qualified from Item_func::Functype
+  NDB_END_COND = 3 // End marker for condition group
 } NDB_ITEM_TYPE;
 
 typedef union ndb_item_qualification {
@@ -93,12 +94,12 @@ typedef union ndb_item_value {
 
 class Ndb_item {
  public:
+  Ndb_item(NDB_ITEM_TYPE item_type);
   Ndb_item(NDB_ITEM_TYPE item_type, 
 	   NDB_ITEM_QUALIFICATION item_qualification,
 	   const Item *item_value);
   Ndb_item(longlong int_value);
   Ndb_item(double real_value);
-  Ndb_item();
   Ndb_item(Field *field, int column_no);
   Ndb_item(Item_func::Functype func_type);
   ~Ndb_item();
@@ -376,12 +377,12 @@ class ha_ndbcluster: public handler
   */
   void cond_clear();
   bool serialize_cond(const COND *cond, Ndb_cond_stack *ndb_cond);
-  Ndb_cond * build_scan_filter_predicate(Ndb_cond* cond, 
+  int build_scan_filter_predicate(Ndb_cond* &cond, 
 				  NdbScanFilter* filter);
-  Ndb_cond * build_scan_filter_group(Ndb_cond* cond, 
+  int build_scan_filter_group(Ndb_cond* &cond, 
 			      NdbScanFilter* filter);
-  void build_scan_filter(Ndb_cond* cond, NdbScanFilter* filter);
-  void generate_scan_filter(Ndb_cond_stack* cond_stack, 
+  int build_scan_filter(Ndb_cond* &cond, NdbScanFilter* filter);
+  int generate_scan_filter(Ndb_cond_stack* cond_stack, 
 			   NdbScanOperation* op);
 
   friend int execute_commit(ha_ndbcluster*, NdbTransaction*);

sql/item_cmpfunc.cc

@@ -2086,6 +2086,7 @@ void Item_cond::traverse_cond(Item_cond_traverser traverser,
     {
       item->traverse_cond(traverser, arg, order);
     }
+    (*traverser)(NULL, arg);
     break;
   case(POSTFIX):
     while ((item= li++))