Merge fix for Bug#59211 to mysql-5.5-security

mysql-test/r/type_year.result

@@ -341,4 +341,18 @@ ta_y	s	tb_y	s
 2001	2001	2001	2001
 DROP TABLE t1;
 #
+# Bug #59211: Select Returns Different Value for min(year) Function
+#
+CREATE TABLE t1(c1 YEAR(4));
+INSERT INTO t1 VALUES (1901),(2155),(0000);
+SELECT * FROM t1;
+c1
+1901
+2155
+0000
+SELECT COUNT(*) AS total_rows, MIN(c1) AS min_value, MAX(c1) FROM t1;
+total_rows	min_value	MAX(c1)
+3	0	2155
+DROP TABLE t1;
+#
 End of 5.1 tests

mysql-test/t/type_year.test

@@ -149,6 +149,16 @@ SELECT ta.y AS ta_y, ta.s, tb.y AS tb_y, tb.s FROM t1 ta, t1 tb HAVING ta_y = tb
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #59211: Select Returns Different Value for min(year) Function
+--echo #
+
+CREATE TABLE t1(c1 YEAR(4));
+INSERT INTO t1 VALUES (1901),(2155),(0000);
+SELECT * FROM t1;
+SELECT COUNT(*) AS total_rows, MIN(c1) AS min_value, MAX(c1) FROM t1;
+DROP TABLE t1;
+
 --echo #
 
 --echo End of 5.1 tests

sql/item.h

@@ -3203,11 +3203,10 @@ class Item_cache: public Item_basic_constant
 protected:
   Item *example;
   table_map used_table_map;
-  /*
-    Field that this object will get value from. This is set/used by 
+  /**
+    Field that this object will get value from. This is used by 
     index-based subquery engines to detect and remove the equality injected 
     by IN->EXISTS transformation.
-    For all other uses of Item_cache, cached_field doesn't matter.
   */  
   Field *cached_field;
   enum enum_field_types cached_field_type;
@@ -3275,6 +3274,14 @@ class Item_cache: public Item_basic_constant
   {
     return (value_cached || cache_value()) && !null_value;
   }
+
+  /** 
+    If this item caches a field value, return pointer to underlying field.
+
+    @return Pointer to field, or NULL if this is not a cache for a field value.
+  */
+  Field* field() { return cached_field; }
+
   virtual void store(Item *item);
   virtual bool cache_value()= 0;
   bool basic_const_item() const

sql/item_cmpfunc.cc

@@ -1208,9 +1208,12 @@ get_year_value(THD *thd, Item ***item_arg, Item **cache_arg,
          value of 2000.
   */
   Item *real_item= item->real_item();
-  if (!(real_item->type() == Item::FIELD_ITEM &&
-        ((Item_field *)real_item)->field->type() == MYSQL_TYPE_YEAR &&
-        ((Item_field *)real_item)->field->field_length == 4))
+  Field *field= NULL;
+  if (real_item->type() == Item::FIELD_ITEM)
+    field= ((Item_field *)real_item)->field;
+  else if (real_item->type() == Item::CACHE_ITEM)
+    field= ((Item_cache *)real_item)->field();
+  if (!(field && field->type() == MYSQL_TYPE_YEAR && field->field_length == 4))
   {
     if (value < 70)
       value+= 100;