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.

3 files changed, 53 insertions, 6 deletions

diff --git a/mysql-test/r/select.result b/mysql-test/r/select.result
index e528b63ddb7..d0b2a575a32 100644
--- a/mysql-test/r/select.result
+++ b/mysql-test/r/select.result
@@ -4591,4 +4591,22 @@ field2
 15:13:38
 drop table A,AA,B,BB;
 #end of test for bug#45266
+# 
+# BUG#48052: Valgrind warning - uninitialized value in init_read_record()
+# 
+CREATE TABLE t1 (
+pk int(11) NOT NULL,
+i int(11) DEFAULT NULL,
+v varchar(1) DEFAULT NULL,
+PRIMARY KEY (pk)
+);
+INSERT INTO t1 VALUES (2,7,'m');
+INSERT INTO t1 VALUES (3,9,'m');
+SELECT  v
+FROM t1
+WHERE NOT pk > 0  
+HAVING v <= 't' 
+ORDER BY pk;
+v
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/mysql-test/t/select.test b/mysql-test/t/select.test
index 7502f451b69..ac65e5cbaf5 100644
--- a/mysql-test/t/select.test
+++ b/mysql-test/t/select.test
@@ -3931,4 +3931,37 @@ SELECT table1 .`time_key` field2  FROM B table1  LEFT JOIN  BB JOIN A table5 ON
 
 drop table A,AA,B,BB;
 --echo #end of test for bug#45266
+
+--echo # 
+--echo # BUG#48052: Valgrind warning - uninitialized value in init_read_record()
+--echo # 
+
+# Needed in 6.0 codebase
+#--echo # Disable Index condition pushdown
+#--replace_column 1 #
+#SELECT @old_icp:=@@engine_condition_pushdown;
+#SET SESSION engine_condition_pushdown = 'OFF';
+
+CREATE TABLE t1 (
+  pk int(11) NOT NULL,
+  i int(11) DEFAULT NULL,
+  v varchar(1) DEFAULT NULL,
+  PRIMARY KEY (pk)
+);
+
+INSERT INTO t1 VALUES (2,7,'m');
+INSERT INTO t1 VALUES (3,9,'m');
+
+SELECT  v
+FROM t1
+WHERE NOT pk > 0  
+HAVING v <= 't' 
+ORDER BY pk;
+
+# Needed in 6.0 codebase
+#--echo # Restore old value for Index condition pushdown
+#SET SESSION engine_condition_pushdown=@old_icp;
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests
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();