Fix detection of recursive calls

lib/monomorph_tree.ml

@@ -390,8 +390,8 @@ let set_tailrec p name =
   (* We have to check the name (of the function) here, because a nested function
      could call recursively its parent *)
   | (nm, _) :: tl when String.equal name nm ->
-      { p with recursion_stack = (nm, Rtail) :: tl }
-  | _ :: _ -> p
+      (true, { p with recursion_stack = (nm, Rtail) :: tl })
+  | _ :: _ -> (false, p)
   | [] -> failwith "Internal Error: Recursion stack empty (set)"
 
 let set_upward = function
@@ -1172,9 +1172,7 @@ and morph_app mk p callee args ret_typ =
   let tailrec, p =
     if ret then
       match callee.monomorph with
-      | Recursive name ->
-          let p = set_tailrec p name.nonmono in
-          (true, p)
+      | Recursive name -> set_tailrec p name.nonmono
       | _ -> (false, p)
     else (false, p)
   in

test/functions.t/nested_recursive.smu

@@ -0,0 +1,15 @@
+let arr = [("heya", 1)]
+
+fun rec consume(storage, opt) {
+  match storage.[opt] {
+    #none: println("none")
+    #some(arr): {
+      array/iter(arr, fun ((str, expr)) {
+        println(str)
+        consume(storage, expr)
+      })
+    }
+  }
+}
+
+consume([#some(copy(arr)), #none], 0)

test/functions.t/run.t

@@ -2177,3 +2177,9 @@ Upward closures are moved closures
   on iteration: 7
   on iteration: 8
   on iteration: 9
+
+Only direct recursive calls count as recursive
+  $ schmu nested_recursive.smu
+  $ valgrind -q --leak-check=yes --show-reachable=yes ./nested_recursive
+  heya
+  none