From cf7a884f125de0a44ddccbc985a96e3a6eb62b8b Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Mon, 21 Jul 2014 12:19:33 +0200
Subject: [PATCH] Stabilize renumber.scm:sort-conts.

* module/language/cps/renumber.scm (sort-conts): Prevent spurious
  continuation reordering.
---
 module/language/cps/renumber.scm | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/module/language/cps/renumber.scm b/module/language/cps/renumber.scm
index 78425ab3c..4f51b7081 100644
--- a/module/language/cps/renumber.scm
+++ b/module/language/cps/renumber.scm
@@ -66,7 +66,14 @@
                    (let ((k-len (vector-ref path-lengths k))
                          (kt-len (vector-ref path-lengths kt)))
                      (cond
-                      ((and k-len kt-len (< k-len kt-len))
+                      ((if kt-len
+                           (or (not k-len)
+                               (< k-len kt-len)
+                               ;; If the path lengths are the
+                               ;; same, preserve original order
+                               ;; to avoid squirreliness.
+                               (and (= k-len kt-len) (< kt k)))
+                           (if k-len #f (< kt k)))
                        (maybe-visit k)
                        (maybe-visit kt))
                       (else