unify inner-d-index when unifying branches; close a few other leaks where meta-d could have been popped without updating inner-d-index

basis/stack-checker/backend/backend.factor

@@ -42,8 +42,11 @@ IN: stack-checker.backend
 : shorten-by ( n seq -- )
     [ length swap - ] keep shorten ; inline
 
+: shorten-d ( n -- )
+    meta-d shorten-by meta-d length update-inner-d ;
+
 : consume-d ( n -- seq )
-    [ ensure-d ] [ meta-d shorten-by ] bi ;
+    [ ensure-d ] [ shorten-d ] bi ;
 
 : output-d ( values -- ) meta-d push-all ;
 

basis/stack-checker/branches/branches.factor

@@ -61,7 +61,9 @@ SYMBOL: quotations
     branch-variable ;
 
 : datastack-phi ( seq -- phi-in phi-out )
-    [ input-count branch-variable ] [ \ meta-d active-variable ] bi
+    [ input-count branch-variable ]
+    [ inner-d-index branch-variable infimum inner-d-index set ]
+    [ \ meta-d active-variable ] tri
     unify-branches
     [ input-count set ] [ ] [ dup >vector \ meta-d set ] tri* ;
 
@@ -80,7 +82,8 @@ SYMBOL: quotations
 : copy-inference ( -- )
     \ meta-d [ clone ] change
     literals [ clone ] change
-    input-count [ ] change ;
+    input-count [ ] change
+    inner-d-index [ ] change ;
 
 GENERIC: infer-branch ( literal -- namespace )
 

basis/stack-checker/transforms/transforms.factor

@@ -18,7 +18,7 @@ IN: stack-checker.transforms
 
 :: ((apply-transform)) ( quot values stack rstate -- )
     rstate recursive-state [ stack quot call-transformer ] with-variable
-    values [ length meta-d shorten-by ] [ #drop, ] bi
+    values [ length shorten-d ] [ #drop, ] bi
     rstate infer-quot ;
 
 : literal-values? ( values -- ? ) [ literal-value? ] all? ;