Fix problem with word redefinition messing up crossref

TODO.FACTOR.txt

@@ -23,7 +23,6 @@
 
 - code walker & exceptions -- test and debug problems
 - code walker and callbacks is broken?
-- look at xref issue
 
 + io:
 

library/collections/graphs.factor

@@ -20,10 +20,8 @@ USING: hashtables kernel namespaces sequences ;
 : (remove-vertex) ( vertex graph -- ) nest remove-hash ;
 
 : remove-vertex ( vertex edges graph -- )
-    [
-        >r dup dup r> call [ nest remove-hash ] each-with
-        namespace remove-hash
-    ] if-graph ; inline
+    [ dupd call [ nest remove-hash ] each-with ] if-graph ;
+    inline
 
 : in-edges ( vertex graph -- seq )
     ?hash dup [ hash-keys ] when ;

library/test/words.factor

@@ -85,12 +85,21 @@ FORGET: another-forgotten
 
 FORGET: foe
 
-! This has to be the last test in the file.
-: test-last ( -- ) ;
-word word-name "last-word-test" set
-
-[ "test-last" ] [ "last-word-test" get ] unit-test
-
 ! xref should not retain references to gensyms
 gensym [ * ] define-compound
 [ t ] [ \ * usage [ interned? not ] subset empty? ] unit-test
+
+DEFER: calls-a-gensym
+\ calls-a-gensym gensym dup "x" set unit define-compound
+[ f ] [ "x" get crossref get hash ] unit-test
+
+! regression
+GENERIC: freakish
+: bar freakish ;
+M: array freakish ;
+[ t ] [ \ bar \ freakish usage member? ] unit-test
+
+! This has to be the last test in the file.
+: test-last ( -- ) ;
+
+[ "test-last" ] [ word word-name ] unit-test

library/words.factor

@@ -49,8 +49,12 @@ M: word set-word-xt ( xt w -- ) 7 set-integer-slot ;
 SYMBOL: crossref
 
 : xref-word ( word -- )
-    dup word-vocabulary
-    [ [ uses ] crossref get add-vertex ] [ drop ] if ;
+    dup word-vocabulary [
+        [ uses [ word-vocabulary ] subset ]
+        crossref get add-vertex
+    ] [
+        drop
+    ] if ;
 
 : usage ( word -- seq ) crossref get in-edges ;
 
@@ -141,6 +145,7 @@ SYMBOL: vocabularies
 
 : forget ( word -- )
     dup unxref-word
+    crossref get [ dupd remove-hash ] when*
     dup word-name swap word-vocabulary vocab remove-hash ;
 
 : forget-vocab ( vocab -- )