Inference bug fix

library/compiler/inference/words.factor

@@ -68,18 +68,13 @@ M: #call-label collect-recursion* ( label node -- )
     dup node-param swap
     [ [ collect-recursion* ] each-node-with ] { } make ;
 
-: amend-d-in ( new old -- )
-    [ length ] 2apply - d-in [ + ] change ;
-
 : join-values ( node -- )
     #! We have to infer recursive labels twice to determine
     #! which literals survive the recursion (eg, quotations)
     #! and which don't (loop indices, etc). The latter cannot
     #! be folded.
-    meta-d get [
-        >r collect-recursion r> add unify-lengths
-        flip [ unify-values ] map dup meta-d set
-    ] keep amend-d-in ;
+    collect-recursion meta-d get add unify-stacks
+    meta-d [ length swap tail* ] change ;
 
 : splice-node ( node -- )
     #! Labels which do not call themselves are just spliced into
@@ -174,7 +169,7 @@ M: symbol apply-object ( word -- )
     {
         "The base case of a recursive word could not be inferred.\n"
         "This means the word calls itself in every control flow path.\n"
-        "See the handbook for details."
+        "See the documentation for details."
     } concat inference-error ;
 
 : notify-base-case ( -- )

library/test/inference.factor

@@ -1,6 +1,6 @@
 IN: temporary
-USING: arrays errors generic inference kernel math
-math-internals namespaces parser sequences test vectors ;
+USING: arrays errors generic inference kernel kernel-internals
+math math-internals namespaces parser sequences test vectors ;
 
 [ f ] [ f [ [ ] map-nodes ] with-node-iterator ] unit-test
 
@@ -74,8 +74,6 @@ math-internals namespaces parser sequences test vectors ;
 
 [ [ bad-recursion-2 ] infer ] unit-test-fails
 
-! Not sure how to fix this one
-
 : funny-recursion
     dup [ funny-recursion 1 ] [ 2 ] if drop ;
 
@@ -209,6 +207,10 @@ DEFER: do-crap
 : do-crap dup [ do-crap ] [ more-crap ] if ;
 [ [ do-crap ] infer ] unit-test-fails
 
+! Regression
+: too-deep dup [ drop ] [ 2dup too-deep too-deep * ] if ; inline
+[ { 2 1 } ] [ [ too-deep ] infer ] unit-test
+
 ! Error reporting is wrong
 G: xyz math-combination ;
 M: fixnum xyz 2array ;