MDEV-31187 Add class Sql_mode_save_for_frm_handling

sql/sql_class.h

@@ -6910,6 +6910,50 @@ class Sql_mode_save
   sql_mode_t old_mode; // SQL mode saved at construction time.
 };
 
+
+/*
+  Save the current sql_mode. Switch off sql_mode flags which can prevent
+  normal parsing of VIEWs, expressions in generated columns.
+  Restore the old sql_mode on destructor.
+*/
+class Sql_mode_save_for_frm_handling: public Sql_mode_save
+{
+public:
+  Sql_mode_save_for_frm_handling(THD *thd)
+   :Sql_mode_save(thd)
+  {
+    /*
+      - MODE_REAL_AS_FLOAT            affect only CREATE TABLE parsing
+      + MODE_PIPES_AS_CONCAT          affect expression parsing
+      + MODE_ANSI_QUOTES              affect expression parsing
+      + MODE_IGNORE_SPACE             affect expression parsing
+      - MODE_IGNORE_BAD_TABLE_OPTIONS affect only CREATE/ALTER TABLE parsing
+      * MODE_ONLY_FULL_GROUP_BY       affect execution
+      * MODE_NO_UNSIGNED_SUBTRACTION  affect execution
+      - MODE_NO_DIR_IN_CREATE         affect table creation only
+      - MODE_POSTGRESQL               compounded from other modes
+      + MODE_ORACLE                   affects Item creation (e.g for CONCAT)
+      - MODE_MSSQL                    compounded from other modes
+      - MODE_DB2                      compounded from other modes
+      - MODE_MAXDB                    affect only CREATE TABLE parsing
+      - MODE_NO_KEY_OPTIONS           affect only SHOW
+      - MODE_NO_TABLE_OPTIONS         affect only SHOW
+      - MODE_NO_FIELD_OPTIONS         affect only SHOW
+      - MODE_MYSQL323                 affect only SHOW
+      - MODE_MYSQL40                  affect only SHOW
+      - MODE_ANSI                     compounded from other modes
+                                      (+ transaction mode)
+      ? MODE_NO_AUTO_VALUE_ON_ZERO    affect UPDATEs
+      + MODE_NO_BACKSLASH_ESCAPES     affect expression parsing
+      + MODE_EMPTY_STRING_IS_NULL     affect expression parsing
+    */
+    thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES |
+                                MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES |
+                                MODE_ORACLE | MODE_EMPTY_STRING_IS_NULL);
+  };
+};
+
+
 class Abort_on_warning_instant_set
 {
   THD *m_thd;

sql/sql_partition.cc

@@ -2589,11 +2589,9 @@ char *generate_partition_syntax_for_frm(THD *thd, partition_info *part_info,
                                         HA_CREATE_INFO *create_info,
                                         Alter_info *alter_info)
 {
-  sql_mode_t old_mode= thd->variables.sql_mode;
-  thd->variables.sql_mode &= ~MODE_ANSI_QUOTES;
+  Sql_mode_save_for_frm_handling sql_mode_save(thd);
   char *res= generate_partition_syntax(thd, part_info, buf_length,
                                              true, create_info, alter_info);
-  thd->variables.sql_mode= old_mode;
   return res;
 }
 

sql/sql_view.cc

@@ -952,8 +952,7 @@ static int mysql_register_view(THD *thd, TABLE_LIST *view,
   view_query.length(0);
   is_query.length(0);
   {
-    sql_mode_t sql_mode= thd->variables.sql_mode & MODE_ANSI_QUOTES;
-    thd->variables.sql_mode&= ~MODE_ANSI_QUOTES;
+    Sql_mode_save_for_frm_handling sql_mode_save(thd);
 
     lex->unit.print(&view_query, enum_query_type(QT_VIEW_INTERNAL |
                                                  QT_ITEM_ORIGINAL_FUNC_NULLIF |
@@ -962,8 +961,6 @@ static int mysql_register_view(THD *thd, TABLE_LIST *view,
                                                QT_WITHOUT_INTRODUCERS |
                                                QT_ITEM_ORIGINAL_FUNC_NULLIF |
                                                QT_NO_WRAPPERS_FOR_TVC_IN_VIEW));
-
-    thd->variables.sql_mode|= sql_mode;
   }
   DBUG_PRINT("info", ("View: %.*s", view_query.length(), view_query.ptr()));
 
@@ -1423,35 +1420,7 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
     lex_start(thd);
     lex->stmt_lex= old_lex;
 
-    sql_mode_t saved_mode= thd->variables.sql_mode;
-    /* switch off modes which can prevent normal parsing of VIEW
-      - MODE_REAL_AS_FLOAT            affect only CREATE TABLE parsing
-      + MODE_PIPES_AS_CONCAT          affect expression parsing
-      + MODE_ANSI_QUOTES              affect expression parsing
-      + MODE_IGNORE_SPACE             affect expression parsing
-      - MODE_IGNORE_BAD_TABLE_OPTIONS affect only CREATE/ALTER TABLE parsing
-      * MODE_ONLY_FULL_GROUP_BY       affect execution
-      * MODE_NO_UNSIGNED_SUBTRACTION  affect execution
-      - MODE_NO_DIR_IN_CREATE         affect table creation only
-      - MODE_POSTGRESQL               compounded from other modes
-      - MODE_ORACLE                   affects Item creation (e.g for CONCAT)
-      - MODE_MSSQL                    compounded from other modes
-      - MODE_DB2                      compounded from other modes
-      - MODE_MAXDB                    affect only CREATE TABLE parsing
-      - MODE_NO_KEY_OPTIONS           affect only SHOW
-      - MODE_NO_TABLE_OPTIONS         affect only SHOW
-      - MODE_NO_FIELD_OPTIONS         affect only SHOW
-      - MODE_MYSQL323                 affect only SHOW
-      - MODE_MYSQL40                  affect only SHOW
-      - MODE_ANSI                     compounded from other modes
-                                      (+ transaction mode)
-      ? MODE_NO_AUTO_VALUE_ON_ZERO    affect UPDATEs
-      + MODE_NO_BACKSLASH_ESCAPES     affect expression parsing
-    */
-    thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES |
-                                MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES |
-                                MODE_ORACLE);
-
+    Sql_mode_save_for_frm_handling sql_mode_save(thd);
     /* Parse the query. */
 
     parse_status= parse_sql(thd, & parser_state, table->view_creation_ctx);
@@ -1464,8 +1433,6 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
         (old_lex->sql_command == SQLCOM_SHOW_CREATE))
         lex->sql_command= old_lex->sql_command;
 
-    thd->variables.sql_mode= saved_mode;
-
     if (dbchanged && mysql_change_db(thd, &old_db, TRUE))
       goto err;
   }

sql/table.cc

@@ -1101,7 +1101,7 @@ bool parse_vcol_defs(THD *thd, MEM_ROOT *mem_root, TABLE *table,
   Field **vfield_ptr= table->vfield;
   Field **dfield_ptr= table->default_field;
   Virtual_column_info **check_constraint_ptr= table->check_constraints;
-  sql_mode_t saved_mode= thd->variables.sql_mode;
+  Sql_mode_save_for_frm_handling sql_mode_save(thd);
   Query_arena backup_arena;
   Virtual_column_info *vcol= 0;
   StringBuffer<MAX_FIELD_WIDTH> expr_str;
@@ -1128,7 +1128,6 @@ bool parse_vcol_defs(THD *thd, MEM_ROOT *mem_root, TABLE *table,
   thd->stmt_arena= table->expr_arena;
   thd->update_charset(&my_charset_utf8mb4_general_ci, table->s->table_charset);
   expr_str.append(&parse_vcol_keyword);
-  thd->variables.sql_mode &= ~(MODE_NO_BACKSLASH_ESCAPES | MODE_EMPTY_STRING_IS_NULL);
 
   while (pos < end)
   {
@@ -1315,7 +1314,6 @@ bool parse_vcol_defs(THD *thd, MEM_ROOT *mem_root, TABLE *table,
   thd->stmt_arena= backup_stmt_arena_ptr;
   if (save_character_set_client)
     thd->update_charset(save_character_set_client, save_collation);
-  thd->variables.sql_mode= saved_mode;
   DBUG_RETURN(res);
 }
 

sql/unireg.cc

@@ -42,7 +42,8 @@
 static uint pack_keys(uchar *,uint, KEY *, ulong, uint);
 static bool pack_header(THD *, uchar *, List<Create_field> &, HA_CREATE_INFO *,
                         ulong, handler *);
-static bool pack_vcols(String *, List<Create_field> &, List<Virtual_column_info> *);
+static bool pack_vcols(THD *thd, String *,
+                       List<Create_field> &, List<Virtual_column_info> *);
 static uint get_interval_id(uint *,List<Create_field> &, Create_field *);
 static bool pack_fields(uchar **, List<Create_field> &, HA_CREATE_INFO*,
                         ulong);
@@ -199,10 +200,8 @@ LEX_CUSTRING build_frm_image(THD *thd, const LEX_CSTRING &table,
     create_info->null_bits++;
   data_offset= (create_info->null_bits + 7) / 8;
 
-  sql_mode_t save_sql_mode= thd->variables.sql_mode;
-  thd->variables.sql_mode &= ~MODE_ANSI_QUOTES;
-  error= pack_vcols(&vcols, create_fields, create_info->check_constraint_list);
-  thd->variables.sql_mode= save_sql_mode;
+  error= pack_vcols(thd, &vcols,
+                    create_fields, create_info->check_constraint_list);
 
   if (unlikely(error))
     DBUG_RETURN(frm);
@@ -635,9 +634,10 @@ static bool pack_expression(String *buf, Virtual_column_info *vcol,
 }
 
 
-static bool pack_vcols(String *buf, List<Create_field> &create_fields,
+static bool pack_vcols(THD *thd, String *buf, List<Create_field> &create_fields,
                        List<Virtual_column_info> *check_constraint_list)
 {
+  Sql_mode_save_for_frm_handling sql_mode_save(thd);
   List_iterator<Create_field> it(create_fields);
   Create_field *field;