A post-merge fix

mysql-test/r/create.result

@@ -1516,6 +1516,22 @@ t1	CREATE TABLE `t1` (
   `c17` int(11) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+
+Bug #26104 Bug on foreign key class constructor
+
+Check that ref_columns is initalized correctly in the constructor
+and semantic checks in mysql_prepare_table work.
+
+We do not need a storage engine that supports foreign keys
+for this test, as the checks are purely syntax-based, and the
+syntax is supported for all engines.
+
+drop table if exists t1,t2;
+create table t1(a int not null, b int not null, primary key (a, b));
+create table t2(a int not null, b int not null, c int not null, primary key (a),
+foreign key fk_bug26104 (b,c) references t1(a));
+ERROR 42000: Incorrect foreign key definition for 'fk_bug26104': Key reference and table reference don't match
+drop table t1;
 End of 5.0 tests
 CREATE TABLE t1 (a int, b int);
 insert into t1 values (1,1),(1,2);