From d46d063f5f3a0dcf11f5924eb2135b2f29c55ca9 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Tue, 1 Sep 2009 04:02:44 -0500
Subject: [PATCH] inheriting from itself would hang a tuple definition.  only
 breaks if tuple is being redefined

---
 core/classes/tuple/parser/parser-tests.factor |  5 +++++
 core/classes/tuple/parser/parser.factor       | 11 +++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/core/classes/tuple/parser/parser-tests.factor b/core/classes/tuple/parser/parser-tests.factor
index 4ee31936a9..0121e217b9 100644
--- a/core/classes/tuple/parser/parser-tests.factor
+++ b/core/classes/tuple/parser/parser-tests.factor
@@ -142,3 +142,8 @@ TUPLE: parsing-corner-case x ;
         "    x 3 }"
     } "\n" join eval( -- tuple )
 ] [ error>> unexpected-eof? ] must-fail-with
+
+TUPLE: bad-inheritance-tuple ;
+[
+    "IN: classes.tuple.parser.tests TUPLE: bad-inheritance-tuple < bad-inheritance-tuple ;" eval( -- )
+] [ error>> bad-inheritance? ] must-fail-with
diff --git a/core/classes/tuple/parser/parser.factor b/core/classes/tuple/parser/parser.factor
index 7ba850f744..61267a464f 100644
--- a/core/classes/tuple/parser/parser.factor
+++ b/core/classes/tuple/parser/parser.factor
@@ -56,11 +56,18 @@ ERROR: invalid-slot-name name ;
 : parse-tuple-slots ( -- )
     ";" parse-tuple-slots-delim ;
 
+ERROR: bad-inheritance class superclass ;
+
+: check-self-inheritance ( class1 class2 -- class1 class2 )
+    2dup = [ bad-inheritance ] when ;
+
 : parse-tuple-definition ( -- class superclass slots )
     CREATE-CLASS
-    scan {
+    scan 2dup = [ ] when {
         { ";" [ tuple f ] }
-        { "<" [ scan-word [ parse-tuple-slots ] { } make ] }
+        { "<" [
+            scan-word check-self-inheritance [ parse-tuple-slots ] { } make
+        ] }
         [ tuple swap [ parse-slot-name [ parse-tuple-slots ] when ] { } make ]
     } case
     dup check-duplicate-slots