MDEV-19124 Assertion `0' failed in Item::val_native

mysql-test/main/type_timestamp.result

@@ -1194,5 +1194,29 @@ CREATE TABLE t2 SELECT 1 AS f FROM t1 GROUP BY FROM_DAYS(d);
 ERROR 22007: Truncated incorrect date value: '0000-00-00'
 DROP TABLE t1;
 #
+# MDEV-19124 Assertion `0' failed in Item::val_native
+#
+CREATE TABLE t1 (d1 TIMESTAMP(5));
+INSERT INTO t1 VALUES ('2018-10-14 15:31:01');
+SELECT LEAD(d1,1) OVER(ORDER BY d1) FROM t1;
+LEAD(d1,1) OVER(ORDER BY d1)
+NULL
+SELECT LAG(d1,1) OVER(ORDER BY d1) FROM t1;
+LAG(d1,1) OVER(ORDER BY d1)
+NULL
+INSERT INTO t1 VALUES ('2018-10-14 15:31:02');
+INSERT INTO t1 VALUES ('2018-10-14 15:31:03');
+SELECT LEAD(d1,1) OVER(ORDER BY d1) FROM t1;
+LEAD(d1,1) OVER(ORDER BY d1)
+2018-10-14 15:31:02.00000
+2018-10-14 15:31:03.00000
+NULL
+SELECT LAG(d1,1) OVER(ORDER BY d1) FROM t1;
+LAG(d1,1) OVER(ORDER BY d1)
+NULL
+2018-10-14 15:31:01.00000
+2018-10-14 15:31:02.00000
+DROP TABLE t1;
+#
 # End of 10.4 tests
 #

mysql-test/main/type_timestamp.test

@@ -786,6 +786,21 @@ CREATE TABLE t2 SELECT 1 AS f FROM t1 GROUP BY FROM_DAYS(d);
 DROP TABLE t1;
 
 
+--echo #
+--echo # MDEV-19124 Assertion `0' failed in Item::val_native
+--echo #
+
+CREATE TABLE t1 (d1 TIMESTAMP(5));
+INSERT INTO t1 VALUES ('2018-10-14 15:31:01');
+SELECT LEAD(d1,1) OVER(ORDER BY d1) FROM t1;
+SELECT LAG(d1,1) OVER(ORDER BY d1) FROM t1;
+INSERT INTO t1 VALUES ('2018-10-14 15:31:02');
+INSERT INTO t1 VALUES ('2018-10-14 15:31:03');
+SELECT LEAD(d1,1) OVER(ORDER BY d1) FROM t1;
+SELECT LAG(d1,1) OVER(ORDER BY d1) FROM t1;
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.4 tests
 --echo #

sql/item_windowfunc.cc

@@ -439,6 +439,14 @@ Item_sum_hybrid_simple::val_str(String *str)
   return retval;
 }
 
+bool Item_sum_hybrid_simple::val_native(THD *thd, Native *to)
+{
+  DBUG_ASSERT(fixed == 1);
+  if (null_value)
+    return true;
+  return val_native_from_item(thd, value, to);
+}
+
 bool Item_sum_hybrid_simple::get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate)
 {
   DBUG_ASSERT(fixed == 1);

sql/item_windowfunc.h

@@ -318,6 +318,7 @@ class Item_sum_hybrid_simple : public Item_sum,
   my_decimal *val_decimal(my_decimal *);
   void reset_field();
   String *val_str(String *);
+  bool val_native(THD *thd, Native *to);
   bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate);
   const Type_handler *type_handler() const
   { return Type_handler_hybrid_field_type::type_handler(); }
@@ -1250,6 +1251,15 @@ class Item_window_func : public Item_func_or_sum
     return res;
   }
 
+  bool val_native(THD *thd, Native *to)
+  {
+    if (force_return_blank)
+      return null_value= true;
+    if (read_value_from_result_field)
+      return val_native_from_field(result_field, to);
+    return val_native_from_item(thd, window_func(), to);
+  }
+
   my_decimal* val_decimal(my_decimal* dec)
   {
     my_decimal *res;