MDEV-16490: It's possible to make a system versioned table without any versioning field

* do not allow versioned table to be without versioned (non-system) fields
* prohibit changing field versioning, when removing table versioning
* handle CREATE...SELECT as well

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

@@ -639,3 +639,45 @@ create or replace table t1 (f1 int) with system versioning;
 alter table t1 drop system versioning, add f2 int with system versioning;
 ERROR HY000: Table `t1` is not system-versioned
 drop table t1;
+# MDEV-16490 It's possible to make a system versioned table without any versioning field
+set @@system_versioning_alter_history=keep;
+create or replace table t (a int) with system versioning engine=innodb;
+alter table t change column a a int without system versioning;
+ERROR HY000: Table `t` must have at least one versioned column
+alter table t
+change column a a int without system versioning,
+add column b int with system versioning;
+show create table t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` int(11) DEFAULT NULL WITHOUT SYSTEM VERSIONING,
+  `b` int(11) DEFAULT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=latin1 WITH SYSTEM VERSIONING
+alter table t
+change column a new_a int,
+drop system versioning;
+show create table t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `new_a` int(11) DEFAULT NULL,
+  `b` int(11) DEFAULT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+alter table t add system versioning;
+alter table t change column new_a a int without system versioning;
+show create table t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` int(11) DEFAULT NULL WITHOUT SYSTEM VERSIONING,
+  `b` int(11) DEFAULT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=latin1 WITH SYSTEM VERSIONING
+alter table t
+add column c int,
+change column c c int without system versioning,
+change column b b int without system versioning;
+ERROR HY000: Table `t` must have at least one versioned column
+alter table t
+add column c int without system versioning,
+change column c c int,
+change column b b int without system versioning;
+drop database test;
+create database test;

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

@@ -515,3 +515,13 @@ row_end datetime(6) generated always as row end,
 period for system_time(row_start, row_end)
 ) with system versioning;
 ERROR HY000: `row_start` must be of type TIMESTAMP(6) for system-versioned table `t`
+# MDEV-16490 It's possible to make a system versioned table without any versioning field
+create or replace table t1 (x int without system versioning)
+with system versioning
+select 1 as y;
+create or replace table t1 (x int without system versioning)
+with system versioning
+select 1 as x;
+ERROR HY000: Table `t1` must have at least one versioned column
+drop database test;
+create database test;

mysql-test/suite/versioning/t/alter.test

@@ -542,3 +542,37 @@ alter table t1 drop system versioning, add f2 int with system versioning;
 
 drop table t1;
 --source suite/versioning/common_finish.inc
+--echo # MDEV-16490 It's possible to make a system versioned table without any versioning field
+
+set @@system_versioning_alter_history=keep;
+create or replace table t (a int) with system versioning engine=innodb;
+--error ER_VERS_TABLE_MUST_HAVE_COLUMNS
+alter table t change column a a int without system versioning;
+
+alter table t
+  change column a a int without system versioning,
+  add column b int with system versioning;
+show create table t;
+
+alter table t
+  change column a new_a int,
+  drop system versioning;
+show create table t;
+
+alter table t add system versioning;
+alter table t change column new_a a int without system versioning;
+show create table t;
+
+--error ER_VERS_TABLE_MUST_HAVE_COLUMNS
+alter table t
+  add column c int,
+  change column c c int without system versioning,
+  change column b b int without system versioning;
+
+alter table t
+  add column c int without system versioning,
+  change column c c int,
+  change column b b int without system versioning;
+
+drop database test;
+create database test;

mysql-test/suite/versioning/t/create.test

@@ -396,3 +396,14 @@ create table t (
 ) with system versioning;
 
 --source suite/versioning/common_finish.inc
+--echo # MDEV-16490 It's possible to make a system versioned table without any versioning field
+create or replace table t1 (x int without system versioning)
+with system versioning
+select 1 as y;
+--error ER_VERS_TABLE_MUST_HAVE_COLUMNS
+create or replace table t1 (x int without system versioning)
+with system versioning
+select 1 as x;
+
+drop database test;
+create database test;

sql/handler.cc

@@ -7164,8 +7164,7 @@ bool Vers_parse_info::fix_implicit(THD *thd, Alter_info *alter_info)
 
 
 bool Table_scope_and_contents_source_st::vers_fix_system_fields(
-  THD *thd, Alter_info *alter_info, const TABLE_LIST &create_table,
-  bool create_select)
+  THD *thd, Alter_info *alter_info, const TABLE_LIST &create_table)
 {
   DBUG_ASSERT(!(alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING));
 
@@ -7205,40 +7204,55 @@ bool Table_scope_and_contents_source_st::vers_fix_system_fields(
   if (vers_info.fix_implicit(thd, alter_info))
     return true;
 
-  int plain_cols= 0; // columns don't have WITH or WITHOUT SYSTEM VERSIONING
-  int vers_cols= 0; // columns have WITH SYSTEM VERSIONING
-  it.rewind();
-  while (const Create_field *f= it++)
-  {
-    if (vers_info.is_start(*f) || vers_info.is_end(*f))
-      continue;
-
-    if (f->versioning == Column_definition::VERSIONING_NOT_SET)
-      plain_cols++;
-    else if (f->versioning == Column_definition::WITH_VERSIONING)
-      vers_cols++;
-  }
-
-  if (!thd->lex->tmp_table() &&
-    // CREATE from SELECT (Create_fields are not yet added)
-    !create_select && vers_cols == 0 && (plain_cols == 0 || !vers_info))
-  {
-    my_error(ER_VERS_TABLE_MUST_HAVE_COLUMNS, MYF(0),
-             create_table.table_name.str);
-    return true;
-  }
-
   return false;
 }
 
 
 bool Table_scope_and_contents_source_st::vers_check_system_fields(
-       THD *thd, Alter_info *alter_info, const TABLE_LIST &create_table)
+        THD *thd, Alter_info *alter_info, const Lex_table_name &table_name,
+        const Lex_table_name &db, int select_count)
 {
   if (!(options & HA_VERSIONED_TABLE))
     return false;
-  return vers_info.check_sys_fields(
-      create_table.table_name, create_table.db, alter_info,
+
+  if (!(alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING))
+  {
+    uint versioned_fields= 0;
+    uint fieldnr= 0;
+    List_iterator<Create_field> field_it(alter_info->create_list);
+    while (Create_field *f= field_it++)
+    {
+      /*
+         The field from the CREATE part can be duplicated in the SELECT part of
+         CREATE...SELECT. In that case double counts should be avoided.
+         select_create::create_table_from_items just pushes the fields back into
+         the create_list, without additional manipulations, so the fields from
+         SELECT go last there.
+       */
+      bool is_dup= false;
+      if (fieldnr >= alter_info->create_list.elements - select_count)
+      {
+        List_iterator<Create_field> dup_it(alter_info->create_list);
+        for (Create_field *dup= dup_it++; !is_dup && dup != f; dup= dup_it++)
+          is_dup= my_strcasecmp(default_charset_info,
+                                dup->field_name.str, f->field_name.str) == 0;
+      }
+
+      if (!(f->flags & VERS_UPDATE_UNVERSIONED_FLAG) && !is_dup)
+        versioned_fields++;
+      fieldnr++;
+    }
+    if (versioned_fields == VERSIONING_FIELDS)
+    {
+      my_error(ER_VERS_TABLE_MUST_HAVE_COLUMNS, MYF(0), table_name.str);
+      return true;
+    }
+  }
+
+  if (!(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING))
+    return false;
+
+  return vers_info.check_sys_fields(table_name, db, alter_info,
       ha_check_storage_engine_flag(db_type, HTON_NATIVE_SYS_VERSIONING));
 }
 
@@ -7343,20 +7357,7 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
     return false;
   }
 
-  if (fix_implicit(thd, alter_info))
-    return true;
-
-  if (alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING)
-  {
-    const bool can_native=
-        ha_check_storage_engine_flag(create_info->db_type,
-                                     HTON_NATIVE_SYS_VERSIONING) ||
-        create_info->db_type->db_type == DB_TYPE_PARTITION_DB;
-    if (check_sys_fields(table_name, share->db, alter_info, can_native))
-      return true;
-  }
-
-  return false;
+  return fix_implicit(thd, alter_info);
 }
 
 bool

sql/handler.h

@@ -2104,11 +2104,12 @@ struct Table_scope_and_contents_source_st:
   }
 
   bool vers_fix_system_fields(THD *thd, Alter_info *alter_info,
-                         const TABLE_LIST &create_table,
-                         bool create_select= false);
+                         const TABLE_LIST &create_table);
 
   bool vers_check_system_fields(THD *thd, Alter_info *alter_info,
-                                const TABLE_LIST &create_table);
+                                const Lex_table_name &table_name,
+                                const Lex_table_name &db,
+                                int select_count= 0);
 
 };
 

sql/sql_insert.cc

@@ -4185,8 +4185,7 @@ TABLE *select_create::create_table_from_items(THD *thd,
   if (!opt_explicit_defaults_for_timestamp)
     promote_first_timestamp_column(&alter_info->create_list);
 
-  if (create_info->vers_fix_system_fields(thd, alter_info, *create_table,
-                                          true))
+  if (create_info->vers_fix_system_fields(thd, alter_info, *create_table))
     DBUG_RETURN(NULL);
 
   while ((item=it++))
@@ -4225,7 +4224,10 @@ TABLE *select_create::create_table_from_items(THD *thd,
     alter_info->create_list.push_back(cr_field, thd->mem_root);
   }
 
-  if (create_info->vers_check_system_fields(thd, alter_info, *create_table))
+  if (create_info->vers_check_system_fields(thd, alter_info,
+                                            create_table->table_name,
+                                            create_table->db,
+                                            select_field_count))
     DBUG_RETURN(NULL);
 
   DEBUG_SYNC(thd,"create_table_select_before_create");

sql/sql_table.cc

@@ -8511,13 +8511,6 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
     }
   }
 
-  if (table->versioned() && !(alter_info->flags & ALTER_DROP_SYSTEM_VERSIONING) &&
-      new_create_list.elements == VERSIONING_FIELDS)
-  {
-    my_error(ER_VERS_TABLE_MUST_HAVE_COLUMNS, MYF(0), table->s->table_name.str);
-    goto err;
-  }
-
   if (!create_info->comment.str)
   {
     create_info->comment.str= table->s->comment.str;
@@ -9553,6 +9546,12 @@ do_continue:;
     DBUG_RETURN(true);
   }
 
+  if (create_info->vers_check_system_fields(thd, alter_info,
+                                            table->s->table_name, table->s->db))
+  {
+    DBUG_RETURN(true);
+  }
+
   set_table_default_charset(thd, create_info, &alter_ctx.db);
 
   if (!opt_explicit_defaults_for_timestamp)
@@ -11170,7 +11169,9 @@ bool Sql_cmd_create_table_like::execute(THD *thd)
     else
     {
       if (create_info.vers_fix_system_fields(thd, &alter_info, *create_table) ||
-	  create_info.vers_check_system_fields(thd, &alter_info, *create_table))
+          create_info.vers_check_system_fields(thd, &alter_info,
+                                               create_table->table_name,
+                                               create_table->db))
 	goto end_with_restore_list;
 
       /*