From: Mark Wooding <mdw@distorted.org.uk>
Date: Mon, 9 Jul 2018 12:04:38 +0000 (+0100)
Subject: src/module-parse.lisp (parse-class-body): Check for duplicate superclasses.
X-Git-Url: https://git.distorted.org.uk/~mdw/sod/commitdiff_plain/0c289c54fb0a31491aa1d2b030851337430ccd71

src/module-parse.lisp (parse-class-body): Check for duplicate superclasses.

It turns out that this is a thing that can happen.  Catch it early
rather than waiting for a less helpful message during CPL construction.
---

diff --git a/src/module-parse.lisp b/src/module-parse.lisp
index 0a3cd28..747bdf7 100644
--- a/src/module-parse.lisp
+++ b/src/module-parse.lisp
@@ -267,7 +267,14 @@
 				  (continue ()
 				    (setf duff t)
 				    (list (find-sod-class "SodObject"))))))
-	      superclasses))
+	      (find-duplicates (lambda (first second)
+				 (declare (ignore second))
+				 (setf duff t)
+				 (cerror* "Class `~A' has duplicate ~
+					   direct superclass `~A'"
+					  name first))
+			       superclasses)
+	      (delete-duplicates superclasses)))
 	   (synthetic-name (or name
 			       (let ((var (synthetic-name)))
 				 (unless pset