Parser: no implicit NOT NULL for system fields [fixes #163]

mysql-test/suite/versioning/r/alter.result

@@ -53,8 +53,8 @@ show create table t;
 Table	Create Table
 t	CREATE TABLE `t` (
   `a` int(11) DEFAULT NULL,
-  `trx_start` timestamp(6) NOT NULL GENERATED ALWAYS AS ROW START,
-  `trx_end` timestamp(6) NOT NULL GENERATED ALWAYS AS ROW END,
+  `trx_start` timestamp(6) GENERATED ALWAYS AS ROW START,
+  `trx_end` timestamp(6) GENERATED ALWAYS AS ROW END,
   PERIOD FOR SYSTEM_TIME (`trx_start`, `trx_end`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 WITH SYSTEM VERSIONING
 alter table t without system versioning;

mysql-test/suite/versioning/r/create.result

@@ -9,8 +9,8 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `XNo` int(10) unsigned DEFAULT NULL,
-  `Sys_start` timestamp(6) NOT NULL GENERATED ALWAYS AS ROW START,
-  `Sys_end` timestamp(6) NOT NULL GENERATED ALWAYS AS ROW END,
+  `Sys_start` timestamp(6) GENERATED ALWAYS AS ROW START,
+  `Sys_end` timestamp(6) GENERATED ALWAYS AS ROW END,
   PERIOD FOR SYSTEM_TIME (`Sys_start`, `Sys_end`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1 WITH SYSTEM VERSIONING
 # Implicit fields test

sql/field.cc

@@ -10630,6 +10630,8 @@ Column_definition::Column_definition(THD *thd, Field *old_field,
   check_constraint= orig_field ? orig_field->check_constraint : 0;
   option_list= old_field->option_list;
   pack_flag= 0;
+  versioning= VERSIONING_NOT_SET;
+  implicit_not_null= false;
 
   switch (sql_type) {
   case MYSQL_TYPE_BLOB:

sql/field.h

@@ -3871,6 +3871,7 @@ class Column_definition: public Sql_alloc
     *check_constraint;               // Check constraint
 
   enum_column_versioning versioning;
+  bool implicit_not_null;
 
   Column_definition():
     comment(null_lex_str),
@@ -3880,7 +3881,8 @@ class Column_definition: public Sql_alloc
     srid(0), geom_type(Field::GEOM_GEOMETRY),
     option_list(NULL), pack_flag(0),
     vcol_info(0), default_value(0), check_constraint(0),
-    versioning(VERSIONING_NOT_SET)
+    versioning(VERSIONING_NOT_SET),
+    implicit_not_null(false)
   {
     interval_list.empty();
   }

sql/sql_yacc.yy

@@ -6305,6 +6305,11 @@ field_def:
               my_yyabort_error((ER_VERS_WRONG_PARAMS, MYF(0), table_name, err));
             }
             *p= field_name;
+            if (lex->last_field->implicit_not_null)
+            {
+              lex->last_field->flags&= ~NOT_NULL_FLAG;
+              lex->last_field->implicit_not_null= false;
+            }
           }
         ;
 
@@ -6517,7 +6522,10 @@ field_type:
                 Unless --explicit-defaults-for-timestamp is given.
               */
               if (!opt_explicit_defaults_for_timestamp)
+              {
                 Lex->last_field->flags|= NOT_NULL_FLAG;
+                Lex->last_field->implicit_not_null= true;
+              }
               $$.set(opt_mysql56_temporal_format ? MYSQL_TYPE_TIMESTAMP2
                                                  : MYSQL_TYPE_TIMESTAMP, $2);
             }
@@ -6704,7 +6712,11 @@ opt_attribute_list:
         ;
 
 attribute:
-          NULL_SYM { Lex->last_field->flags&= ~ NOT_NULL_FLAG; }
+          NULL_SYM
+          {
+            Lex->last_field->flags&= ~ NOT_NULL_FLAG;
+            Lex->last_field->implicit_not_null= false;
+          }
         | DEFAULT column_default_expr { Lex->last_field->default_value= $2; }
         | ON UPDATE_SYM NOW_SYM opt_default_time_precision
           {
@@ -6731,7 +6743,11 @@ attribute:
         ;
 
 serial_attribute:
-          not NULL_SYM { Lex->last_field->flags|= NOT_NULL_FLAG; }
+          not NULL_SYM
+          {
+            Lex->last_field->flags|= NOT_NULL_FLAG;
+            Lex->last_field->implicit_not_null= false;
+          }
         | opt_primary KEY_SYM
           {
             LEX *lex=Lex;