From b958e21f466fea4b078e6b98e434346c8c90bd4a Mon Sep 17 00:00:00 2001
From: Casey Klein <clklein@racket-lang.org>
Date: Tue, 29 Mar 2011 13:04:20 -0500
Subject: [PATCH] Fixes another bug in the stepper's diff highlighting

---
 collects/redex/private/sexp-diffs.rkt |  6 +++++-
 collects/redex/tests/stepper-test.rkt | 16 ++++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/collects/redex/private/sexp-diffs.rkt b/collects/redex/private/sexp-diffs.rkt
index 121ad16724..9bdc0768fa 100644
--- a/collects/redex/private/sexp-diffs.rkt
+++ b/collects/redex/private/sexp-diffs.rkt
@@ -52,7 +52,9 @@
   (let loop ([s s])
     (cond
       [(pair? s) (cons (loop (car s))
-                       (loop (cdr s)))]
+                       (if (null? (cdr s))
+                           '()
+                           (loop (cdr s))))]
       [(vector? s)
        (list->vector (map loop (vector->list s)))]
       [(box? s)
@@ -60,6 +62,8 @@
       [(syntax? s) (datum->syntax s (unkink (loop (syntax-e s))) s)]
       [(number? s) (make-wrap s)]
       [(symbol? s) (make-wrap s)]
+      [(null? s) (make-wrap s)]
+      [(boolean? s) (make-wrap s)]
       [else s])))
 
 (define-struct wrap (content) #:inspector (make-inspector))
diff --git a/collects/redex/tests/stepper-test.rkt b/collects/redex/tests/stepper-test.rkt
index aed8332f66..ba28cca1e8 100644
--- a/collects/redex/tests/stepper-test.rkt
+++ b/collects/redex/tests/stepper-test.rkt
@@ -20,10 +20,11 @@
          [change-path 'dont-care]
          [init-cw (initial-char-width)]))
   (define (ranges node)
-    (map (λ (range) (cons (text:range-start range)
-                          (text:range-end range)))
-         (send (send (send node get-big-snip) get-editor)
-               get-highlighted-ranges)))
+    (sort (map (λ (range) (cons (text:range-start range)
+                                (text:range-end range)))
+               (send (send (send node get-big-snip) get-editor)
+                     get-highlighted-ranges))
+          < #:key car))
   (define from-node (make-node from))
   (define to-node (make-node to))
   (show-diff from-node to-node)
@@ -34,4 +35,11 @@
 (test (diff (term (,'hole a)) (term (,'hole b)))
       (cons (list (cons 8 9)) (list (cons 8 9))))
 
+(test (diff (term (() #f () #f)) (term (1 2 () #f)))
+      (cons (list (cons 1 3) (cons 4 6))
+            (list (cons 1 2) (cons 3 4))))
+(test (diff (term (<> ((a b)) () e)) (term (<> ((a b)) () (c d))))
+      (cons (list (cons 15 16))
+            (list (cons 15 20))))
+
 (print-tests-passed 'stepper-test.ss)
\ No newline at end of file