tests: add a regression test for the issue #568

- also fix test which assumed constant unreadable representation of
  the object of class compiler-test-class

src/tests/normal-tests/compiler.lsp

@@ -692,7 +692,9 @@
     (load file)
     (delete-file "make-load-form.lsp")
     (delete-file file))
-  (is-equal "#1=(1 2 3 #<a CL-TEST::COMPILER-TEST-CLASS> #1#)" (foo.0030))
+  (let ((str (foo.0030)))
+    (is (and (search "#1=(1 2 3 #<a CL-TEST::COMPILER-TEST-CLASS" str)
+             (search "> #1#)" str))))
   (is (eq (compiler-test-parent a.0030) b.0030))
   (is (eq (first (compiler-test-children b.0030)) a.0030)))
 

src/tests/normal-tests/metaobject-protocol.lsp

@@ -664,3 +664,15 @@ the metaclass")
     (signals error (make-instance 'foo1))
     (finishes (defclass foo2 () ()))
     (finishes (make-instance 'foo1))))
+
+;;; Date 2020-04-05
+;;; URL: https://gitlab.com/embeddable-common-lisp/ecl/-/issues/568
+;;; Fixed: 557541f3
+;;; Description
+;;;
+;;;     Finalizing inheritance of a standard-effective-slot-definition
+;;;     lead to the infinite recursion by making all its instances
+;;;     obsolete (including its own slots!).
+(test mop.0025.xxx
+  (clos:finalize-inheritance
+   (find-class 'clos:standard-effective-slot-definition)))