Another attempt to fix bug mdev-10785 + cleanup for the previous attempt.

sql/sql_derived.cc

@@ -1242,18 +1242,11 @@ bool pushdown_cond_for_derived(THD *thd, Item *cond, TABLE_LIST *derived)
                          (uchar*) sl);
     if (!extracted_cond_copy)
       continue;
-    /*
-      Create the conjunction of the existing having condition of sl
-      and the pushed condition, take it as the new having condition of sl
-      and fix this new condition
-    */
+
     extracted_cond_copy->walk(&Item::cleanup_processor, 0, 0);
     sl->cond_pushed_into_having= extracted_cond_copy;
   }
   thd->lex->current_select= save_curr_select;
   return false;
-err:
-  thd->lex->current_select= save_curr_select;
-  return true;
 }
 

sql/sql_lex.cc

@@ -4923,6 +4923,7 @@ void binlog_unsafe_map_init()
 
 void st_select_lex::collect_grouping_fields(THD *thd) 
 {
+  grouping_tmp_fields.empty();
   List_iterator<Item> li(join->fields_list);
   Item *item= li++;
   for (uint i= 0; i < master_unit()->derived->table->s->fields; i++, (item=li++))