Bug#48052: Valgrind warning - uninitialized value in

           init_read_record() - (records.cc:274)
      
Item_cond::used_tables_cache was accessed in
records.cc#init_read_record() without being initialized. It had
not been initialized because it was wrongly assumed that the
Item's variables would not be accessed, and hence
quick_fix_field() was used instead of fix_fields() to save a few
CPU cycles at creation time.

The fix is to properly initilize the Item by replacing
quick_fix_field() with fix_fields().


mysql-test/r/select.result:
  Add test for BUG#48052
mysql-test/t/select.test:
  Add test for BUG#48052
sql/sql_select.cc:
  Properly initialize Item_cond_and by calling fix_fields (instead of quick_fix_field) when the Item that "ANDs" WHERE clause conditions with HAVING clause conditions is created.

1 files changed, 2 insertions, 6 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 7a4ab1c8365..00080b9b9d9 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -2131,17 +2131,13 @@ JOIN::exec()
 	    DBUG_VOID_RETURN;
 	if (!curr_table->select->cond)
 	  curr_table->select->cond= sort_table_cond;
-	else					// This should never happen
+	else
 	{
 	  if (!(curr_table->select->cond=
 		new Item_cond_and(curr_table->select->cond,
 				  sort_table_cond)))
 	    DBUG_VOID_RETURN;
-	  /*
-	    Item_cond_and do not need fix_fields for execution, its parameters
-	    are fixed or do not need fix_fields, too
-	  */
-	  curr_table->select->cond->quick_fix_field();
+	  curr_table->select->cond->fix_fields(thd, 0);
 	}
 	curr_table->select_cond= curr_table->select->cond;
 	curr_table->select_cond->top_level_item();