MDEV-22660 System versioning cleanups

- Cleaned up Vers_parse_info::check_sys_fields();
- Renamed VERS_SYS_START_FLAG, VERS_SYS_END_FLAG to VERS_ROW_START,
  VERS_ROW_END.

9 files changed, 64 insertions, 67 deletions

diff --git a/include/mysql_com.h b/include/mysql_com.h
index b1534b1d746..234b6133676 100644
--- a/include/mysql_com.h
+++ b/include/mysql_com.h
@@ -193,13 +193,13 @@ enum enum_indicator_type
 #define FIELD_FLAGS_COLUMN_FORMAT_MASK (3U << FIELD_FLAGS_COLUMN_FORMAT)
 #define FIELD_IS_DROPPED (1U << 26)     /* Intern: Field is being dropped */
 
-#define VERS_SYS_START_FLAG (1 << 27)   /* autogenerated column declared with
+#define VERS_ROW_START (1 << 27)   /* autogenerated column declared with
                                              `generated always as row start`
                                               (see II.a SQL Standard) */
-#define VERS_SYS_END_FLAG (1 << 28)     /* autogenerated column declared with
+#define VERS_ROW_END (1 << 28)     /* autogenerated column declared with
                                            `generated always as row end`
                                             (see II.a SQL Standard).*/
-#define VERS_SYSTEM_FIELD (VERS_SYS_START_FLAG | VERS_SYS_END_FLAG)
+#define VERS_SYSTEM_FIELD (VERS_ROW_START | VERS_ROW_END)
 #define VERS_UPDATE_UNVERSIONED_FLAG (1 << 29) /* column that doesn't support
                                                 system versioning when table
                                                 itself supports it*/
diff --git a/sql/field.cc b/sql/field.cc
index cba6df52b62..ddb309c3262 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -2360,7 +2360,7 @@ Field *Field::make_new_field(MEM_ROOT *root, TABLE *new_table,
   tmp->unireg_check= Field::NONE;
   tmp->flags&= (NOT_NULL_FLAG | BLOB_FLAG | UNSIGNED_FLAG |
                 ZEROFILL_FLAG | BINARY_FLAG | ENUM_FLAG | SET_FLAG |
-                VERS_SYS_START_FLAG | VERS_SYS_END_FLAG |
+                VERS_ROW_START | VERS_ROW_END |
                 VERS_UPDATE_UNVERSIONED_FLAG);
   tmp->reset_fields();
   tmp->invisible= VISIBLE;
@@ -10967,7 +10967,7 @@ Field *make_field(TABLE_SHARE *share,
                  f_is_zerofill(pack_flag) != 0,
                  f_is_dec(pack_flag) == 0);
   case MYSQL_TYPE_LONGLONG:
-    if (flags & (VERS_SYS_START_FLAG|VERS_SYS_END_FLAG))
+    if (flags & (VERS_ROW_START|VERS_ROW_END))
     {
       return new (mem_root)
         Field_vers_trx_id(ptr, field_length, null_pos, null_bit,
diff --git a/sql/field.h b/sql/field.h
index 825a0dae7aa..7d60e0953f8 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -1499,7 +1499,7 @@ public:
 
   bool vers_sys_field() const
   {
-    return flags & (VERS_SYS_START_FLAG | VERS_SYS_END_FLAG);
+    return flags & (VERS_ROW_START | VERS_ROW_END);
   }
 
   bool vers_update_unversioned() const
@@ -4469,7 +4469,7 @@ public:
   }
   bool vers_sys_field() const
   {
-    return flags & (VERS_SYS_START_FLAG | VERS_SYS_END_FLAG);
+    return flags & (VERS_ROW_START | VERS_ROW_END);
   }
   void create_length_to_internal_length_bit();
   void create_length_to_internal_length_newdecimal();
@@ -4813,6 +4813,15 @@ public:
   }
   /* Used to make a clone of this object for ALTER/CREATE TABLE */
   Create_field *clone(MEM_ROOT *mem_root) const;
+
+  bool is_some_bigint() const
+  {
+    return type_handler() == &type_handler_longlong ||
+           type_handler() == &type_handler_vers_trx_id;
+  }
+
+  bool vers_check_timestamp(const Lex_table_name &table_name) const;
+  bool vers_check_bigint(const Lex_table_name &table_name) const;
 };
 
 
diff --git a/sql/handler.cc b/sql/handler.cc
index c0a810a72bc..f46e51a34ce 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -7122,11 +7122,11 @@ bool Vers_parse_info::is_end(const char *name) const
 }
 bool Vers_parse_info::is_start(const Create_field &f) const
 {
-  return f.flags & VERS_SYS_START_FLAG;
+  return f.flags & VERS_ROW_START;
 }
 bool Vers_parse_info::is_end(const Create_field &f) const
 {
-  return f.flags & VERS_SYS_END_FLAG;
+  return f.flags & VERS_ROW_END;
 }
 
 static Create_field *vers_init_sys_field(THD *thd, const char *field_name, int flags, bool integer)
@@ -7186,8 +7186,8 @@ bool Vers_parse_info::fix_implicit(THD *thd, Alter_info *alter_info)
   system_time= start_end_t(default_start, default_end);
   as_row= system_time;
 
-  if (vers_create_sys_field(thd, default_start, alter_info, VERS_SYS_START_FLAG) ||
-      vers_create_sys_field(thd, default_end, alter_info, VERS_SYS_END_FLAG))
+  if (vers_create_sys_field(thd, default_start, alter_info, VERS_ROW_START) ||
+      vers_create_sys_field(thd, default_end, alter_info, VERS_ROW_END))
   {
     return true;
   }
@@ -7346,7 +7346,7 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
           return true;
         }
         my_error(ER_VERS_DUPLICATE_ROW_START_END, MYF(0),
-                 f->flags & VERS_SYS_START_FLAG ? "START" : "END", f->field_name.str);
+                 f->flags & VERS_ROW_START ? "START" : "END", f->field_name.str);
         return true;
       }
     }
@@ -7451,13 +7451,13 @@ Vers_parse_info::fix_create_like(Alter_info &alter_info, HA_CREATE_INFO &create_
 
   while ((f= it++))
   {
-    if (f->flags & VERS_SYS_START_FLAG)
+    if (f->flags & VERS_ROW_START)
     {
       f_start= f;
       if (f_end)
         break;
     }
-    else if (f->flags & VERS_SYS_END_FLAG)
+    else if (f->flags & VERS_ROW_END)
     {
       f_end= f;
       if (f_start)
@@ -7519,37 +7519,31 @@ bool Vers_parse_info::check_conditions(const Lex_table_name &table_name,
   return false;
 }
 
-static bool is_versioning_timestamp(const Create_field *f)
-{
-  return f->type_handler() == &type_handler_timestamp2 &&
-         f->length == MAX_DATETIME_FULL_WIDTH;
-}
-
-static bool is_some_bigint(const Create_field *f)
-{
-  return f->type_handler() == &type_handler_longlong ||
-         f->type_handler() == &type_handler_vers_trx_id;
-}
 
-static bool is_versioning_bigint(const Create_field *f)
+bool Create_field::vers_check_timestamp(const Lex_table_name &table_name) const
 {
-  return is_some_bigint(f) && f->flags & UNSIGNED_FLAG &&
-         f->length == MY_INT64_NUM_DECIMAL_DIGITS - 1;
-}
+  if (type_handler() == &type_handler_timestamp2 &&
+      length == MAX_DATETIME_FULL_WIDTH)
+    return false;
 
-static bool require_timestamp(const Create_field *f, Lex_table_name table_name)
-{
-  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), f->field_name.str, "TIMESTAMP(6)",
+  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), field_name.str, "TIMESTAMP(6)",
            table_name.str);
   return true;
 }
-static bool require_bigint(const Create_field *f, Lex_table_name table_name)
+
+
+bool Create_field::vers_check_bigint(const Lex_table_name &table_name) const
 {
-  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), f->field_name.str,
+  if (is_some_bigint() && flags & UNSIGNED_FLAG &&
+      length == MY_INT64_NUM_DECIMAL_DIGITS - 1)
+    return false;
+
+  my_error(ER_VERS_FIELD_WRONG_TYPE, MYF(0), field_name.str,
            "BIGINT(20) UNSIGNED", table_name.str);
   return true;
 }
 
+
 bool Vers_parse_info::check_sys_fields(const Lex_table_name &table_name,
                                        const Lex_table_name &db,
                                        Alter_info *alter_info,
@@ -7564,37 +7558,31 @@ bool Vers_parse_info::check_sys_fields(const Lex_table_name &table_name,
   List_iterator<Create_field> it(alter_info->create_list);
   while (Create_field *f= it++)
   {
-    if (!row_start && f->flags & VERS_SYS_START_FLAG)
+    if (!row_start && f->flags & VERS_ROW_START)
       row_start= f;
-    else if (!row_end && f->flags & VERS_SYS_END_FLAG)
+    else if (!row_end && f->flags & VERS_ROW_END)
       row_end= f;
   }
 
-  const bool expect_timestamp=
-      !can_native || !is_some_bigint(row_start) || !is_some_bigint(row_end);
-
-  if (expect_timestamp)
+  if (!can_native ||
+      !row_start->is_some_bigint() ||
+      !row_end->is_some_bigint())
   {
-    if (!is_versioning_timestamp(row_start))
-      return require_timestamp(row_start, table_name);
-
-    if (!is_versioning_timestamp(row_end))
-      return require_timestamp(row_end, table_name);
+    if (row_start->vers_check_timestamp(table_name) ||
+        row_end->vers_check_timestamp(table_name))
+      return true;
   }
   else
   {
-    if (!is_versioning_bigint(row_start))
-      return require_bigint(row_start, table_name);
-
-    if (!is_versioning_bigint(row_end))
-      return require_bigint(row_end, table_name);
-  }
+    if (row_start->vers_check_bigint(table_name) ||
+        row_end->vers_check_bigint(table_name))
+      return true;
 
-  if (is_versioning_bigint(row_start) && is_versioning_bigint(row_end) &&
-      !TR_table::use_transaction_registry)
-  {
-    my_error(ER_VERS_TRT_IS_DISABLED, MYF(0));
-    return true;
+    if (!TR_table::use_transaction_registry)
+    {
+      my_error(ER_VERS_TRT_IS_DISABLED, MYF(0));
+      return true;
+    }
   }
 
   return false;
diff --git a/sql/item_vers.cc b/sql/item_vers.cc
index 76cda6a5ea2..6103c53fd51 100644
--- a/sql/item_vers.cc
+++ b/sql/item_vers.cc
@@ -30,7 +30,7 @@ bool Item_func_history::val_bool()
 {
   Item_field *f= static_cast<Item_field *>(args[0]);
   DBUG_ASSERT(f->fixed);
-  DBUG_ASSERT(f->field->flags & VERS_SYS_END_FLAG);
+  DBUG_ASSERT(f->field->flags & VERS_ROW_END);
   return !f->field->is_max();
 }
 
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 4fc8ebb5a60..00e1d30f209 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -8322,7 +8322,7 @@ bool LEX::last_field_generated_always_as_row_start()
   Vers_parse_info &info= vers_get_info();
   Lex_ident *p= &info.as_row.start;
   return last_field_generated_always_as_row_start_or_end(p, "START",
-                                                         VERS_SYS_START_FLAG);
+                                                         VERS_ROW_START);
 }
 
 
@@ -8331,7 +8331,7 @@ bool LEX::last_field_generated_always_as_row_end()
   Vers_parse_info &info= vers_get_info();
   Lex_ident *p= &info.as_row.end;
   return last_field_generated_always_as_row_start_or_end(p, "END",
-                                                         VERS_SYS_END_FLAG);
+                                                         VERS_ROW_END);
 }
 
 
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 35e0c7364f5..5a3c27832ac 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -2288,11 +2288,11 @@ int show_create_table(THD *thd, TABLE_LIST *table_list, String *packet,
     }
     else
     {
-      if (field->flags & VERS_SYS_START_FLAG)
+      if (field->flags & VERS_ROW_START)
       {
         packet->append(STRING_WITH_LEN(" GENERATED ALWAYS AS ROW START"));
       }
-      else if (field->flags & VERS_SYS_END_FLAG)
+      else if (field->flags & VERS_ROW_END)
       {
         packet->append(STRING_WITH_LEN(" GENERATED ALWAYS AS ROW END"));
       }
@@ -6080,7 +6080,7 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
     }
     else if (field->flags & VERS_SYSTEM_FIELD)
     {
-      if (field->flags & VERS_SYS_START_FLAG)
+      if (field->flags & VERS_ROW_START)
       {
         table->field[21]->store(STRING_WITH_LEN("ROW START"), cs);
         buf.set(STRING_WITH_LEN("STORED GENERATED"), cs);
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 9aae74a613d..2b796403dc8 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -8209,7 +8209,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       def= new (thd->mem_root) Create_field(thd, field, field);
       def->invisible= INVISIBLE_SYSTEM;
       alter_info->flags|= ALTER_CHANGE_COLUMN;
-      if (field->flags & VERS_SYS_START_FLAG)
+      if (field->flags & VERS_ROW_START)
         create_info->vers_info.as_row.start= def->field_name= Vers_parse_info::default_start;
       else
         create_info->vers_info.as_row.end= def->field_name= Vers_parse_info::default_end;
@@ -8250,9 +8250,9 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       !vers_system_invisible)
   {
     StringBuffer<NAME_LEN*3> tmp;
-    if (!(dropped_sys_vers_fields & VERS_SYS_START_FLAG))
+    if (!(dropped_sys_vers_fields & VERS_ROW_START))
       append_drop_column(thd, &tmp, table->vers_start_field());
-    if (!(dropped_sys_vers_fields & VERS_SYS_END_FLAG))
+    if (!(dropped_sys_vers_fields & VERS_ROW_END))
       append_drop_column(thd, &tmp, table->vers_end_field());
     my_error(ER_MISSING, MYF(0), table->s->table_name.str, tmp.c_ptr());
     goto err;
diff --git a/sql/table.cc b/sql/table.cc
index 18bb28e0863..0bef0fc29a1 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -2059,9 +2059,9 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
     if (versioned)
     {
       if (i == row_start_field)
-        flags|= VERS_SYS_START_FLAG;
+        flags|= VERS_ROW_START;
       else if (i == row_end_field)
-        flags|= VERS_SYS_END_FLAG;
+        flags|= VERS_ROW_END;
 
       if (flags & VERS_SYSTEM_FIELD)
       {