diff --git a/drracket-core-lib/browser/external.rkt b/drracket-core-lib/browser/external.rkt
index 2fba81299..ed9956064 100644
--- a/drracket-core-lib/browser/external.rkt
+++ b/drracket-core-lib/browser/external.rkt
@@ -40,10 +40,11 @@
   ;; sync-current-proxy-servers : proxy-pref -> void
   ;; syncs current-proxy-servers parameter with the proxy-pref-val
   (define (sync-current-proxy-servers pref-val)
-    (let* ([ops (current-proxy-servers)]
-           [removed (remove-all-proxies "http" ops)])
-      (current-proxy-servers
-       (if pref-val (cons pref-val removed) removed))))
+    (define ops (current-proxy-servers))
+    (define removed (remove-all-proxies "http" ops))
+    (current-proxy-servers (if pref-val
+                               (cons pref-val removed)
+                               removed)))
 
   (define (remove-all-proxies scheme proxies)
     (filter (lambda (x) (and (pair? x) (not (equal? (car x) scheme))))
@@ -84,9 +85,8 @@
                            (loop (add1 tries)))))))
 
   (define unix-browser-names
-    (map (lambda (s)
-           (string-titlecase (regexp-replace* #rx"-" (symbol->string s) " ")))
-         raw:unix-browser-list))
+    (for/list ([s (in-list raw:unix-browser-list)])
+      (string-titlecase (regexp-replace* #rx"-" (symbol->string s) " "))))
 
   ;; : (U str #f) -> (U symbol #f)
   ;; to prompt the user for a browser preference
@@ -94,38 +94,37 @@
   ;;  and in that case, the user can choose to use the internal
   ;;  broswer.
   (define (choose-browser url)
-    (let* ([title (string-constant choose-browser)]
-           [d (make-object dialog% title)]
-           [main-pane (make-object vertical-pane% d)]
-           [internal-ok? (not url)]
-           [ok? #f]
-           [orig-external (fw:preferences:get 'external-browser)])
-      (make-object message% title main-pane)
-      ;; No need to show the URL (it can be very long)
-      ;; (when url
-      ;;   (make-object message% (format "URL: ~a" url) main-pane))
-      (let-values ([(panel callbacks) (make-help-browser-preference-panel internal-ok? #f (lambda (f) (f main-pane)))])
-        (let*-values ([(button-pane) (instantiate horizontal-panel% (main-pane)
-                                                  (alignment '(right center)))]
-                      [(ok-button cancel-button)
-                       (fw:gui-utils:ok/cancel-buttons
-                        button-pane
-                        (lambda (b e) (set! ok? #t) (send d show #f))
-                        (lambda (b e)
-                          (fw:preferences:set 'external-browser orig-external)
-                          (send d show #f)))]
-                      [(enable-button) (lambda (_n _v)
-                                         (queue-callback
-                                          (lambda ()
-                                            (send ok-button enable (fw:preferences:get 'external-browser)))))])
-          (send ok-button enable #f)
-          (set! callbacks
-                (cons
-                 (fw:preferences:add-callback 'external-browser enable-button)
-                 callbacks)))
-        (send d show #t)
-        (map (lambda (f) (f)) callbacks)
-        ok?)))
+    (define title (string-constant choose-browser))
+    (define d (make-object dialog% title))
+    (define main-pane (make-object vertical-pane% d))
+    (define internal-ok? (not url))
+    (define ok? #f)
+    (define orig-external (fw:preferences:get 'external-browser))
+    (make-object message% title main-pane)
+    ;; No need to show the URL (it can be very long)
+    ;; (when url
+    ;;   (make-object message% (format "URL: ~a" url) main-pane))
+    (define-values (panel callbacks)
+      (make-help-browser-preference-panel internal-ok? #f (lambda (f) (f main-pane))))
+    (let*-values ([(button-pane) (instantiate horizontal-panel% (main-pane)
+                                   [alignment '(right center)])]
+                  [(ok-button cancel-button) (fw:gui-utils:ok/cancel-buttons
+                                              button-pane
+                                              (lambda (b e)
+                                                (set! ok? #t)
+                                                (send d show #f))
+                                              (lambda (b e)
+                                                (fw:preferences:set 'external-browser orig-external)
+                                                (send d show #f)))]
+                  [(enable-button)
+                   (lambda (_n _v)
+                     (queue-callback
+                      (lambda () (send ok-button enable (fw:preferences:get 'external-browser)))))])
+      (send ok-button enable #f)
+      (set! callbacks (cons (fw:preferences:add-callback 'external-browser enable-button) callbacks)))
+    (send d show #t)
+    (map (lambda (f) (f)) callbacks)
+    ok?)
 
   (define panel-installed? #f)
   (define prefs-panel #f)
@@ -140,11 +139,11 @@
        (lambda (f) (fw:preferences:add-panel
                     (string-constant browser)
                     (lambda (parent)
-                      (let-values ([(panel cbs) (f parent)])
-                        (set! prefs-panel panel)
-                        (map (lambda (f) (f panel)) additions)
-                        (set! additions null)
-                        panel)))))))
+                      (define-values (panel cbs) (f parent))
+                      (set! prefs-panel panel)
+                      (map (lambda (f) (f panel)) additions)
+                      (set! additions null)
+                      panel))))))
 
   (define (add-to-browser-prefs-panel proc)
     (if prefs-panel
@@ -155,150 +154,153 @@
     (mk
      (lambda (parent)
        (define callbacks null)
-       (let ([pref-panel (instantiate vertical-panel% ()
-                                      [parent parent]
-                                      [alignment '(left center)])])
-
-         ;; -------------------- external browser for Unix --------------------
-         (when (unix-browser?)
-           (unless synchronized?
-             ;; Keep 'external-browser in sync
-             (fw:preferences:add-callback 'external-browser
-               (lambda (name browser)
-                 (try-put-preferences (list 'external-browser) (list browser)))))
-
-           (letrec ([v-panel (instantiate group-box-panel% ()
-                                          (parent pref-panel)
-                                          (alignment '(right center))
-                                          (stretchable-height #f)
-                                          (label (string-constant external-browser-choice-title)))]
-                    [h-panel (instantiate horizontal-panel% ()
-                                          (parent v-panel)
-                                          (alignment '(center bottom)))]
-                    [none-index (length raw:unix-browser-list)]
-                    [custom-index (add1 none-index)]
-                    [r (instantiate radio-box% ()
-                                    (label #f)
-                                    (choices (append unix-browser-names
-                                                     (list (string-constant no-browser)
-                                                           (string-constant browser-command-line-label))))
-                                    (parent h-panel)
-                                    (callback
-                                     (lambda (radio event)
-                                       (let ([n (send radio get-selection)])
-                                         (set-browser!
-                                          (cond
-                                            [(= n none-index) #f]
-                                            [(= n custom-index) (get-custom)]
-                                            [else (list-ref raw:unix-browser-list n)]))))))]
-                    [select-custom
-                     (lambda (_ __)
-                       (send r set-selection custom-index)
-                       (set-browser! (get-custom)))]
-                    [get-custom
-                     (lambda () (cons (send pre get-value) (send post get-value)))]
-                    [template-panel (instantiate horizontal-panel% (h-panel)
-                                                 (spacing 0)
-                                                 (stretchable-height #f))]
-                    [pre (instantiate text-field% ()
-                                      (label #f) (parent template-panel) (callback select-custom)
-                                      (horiz-margin 0))]
-                    [mess (instantiate message% () (label "<URL>") (parent template-panel)
-                                       (horiz-margin 0))]
-                    [post (instantiate text-field% ()
-                                       (label #f) (parent template-panel) (callback select-custom)
-                                       (horiz-margin 0))]
-                    [note1 (instantiate message% ((string-constant browser-cmdline-expl-line-1)
-                                                  v-panel))]
-                    [note2 (instantiate message% ((string-constant browser-cmdline-expl-line-2)
-                                                  v-panel))]
-                    [refresh-controls (lambda (pref)
-                                        (if (pair? pref)
-                                          (begin
-                                            (send r set-selection custom-index)
-                                            (send pre set-value (car pref))
-                                            (send post set-value (cdr pref)))
-                                          (let init ([x raw:unix-browser-list] [n 0])
-                                            (cond
-                                              [(null? x) (send r set-selection n)]
-                                              [else (if (eq? pref (car x))
-                                                      (send r set-selection n)
-                                                      (init (cdr x) (add1 n)))]))))])
-
-             (unless ask-later?
-               (send r enable none-index #f))
-
-             (refresh-controls (fw:preferences:get 'external-browser))
-             (set! callbacks
-                   (cons (fw:preferences:add-callback 'external-browser
-                           (lambda (name browser) (refresh-controls browser)))
-                    callbacks))))
-
-         ;; -------------------- proxy for doc downloads --------------------
-         (when set-help?
-           (letrec ([p (instantiate group-box-panel% ()
-                                    [label (string-constant http-proxy)]
-                                    [parent pref-panel]
-                                    [stretchable-height #f]
-                                    [alignment '(left top)])]
-                    [rb (make-object radio-box%
-                                     #f (list (string-constant proxy-direct-connection)
-                                              (string-constant proxy-use-proxy))
-                                     p
-                                     (lambda (r e)
-                                       (let ([proxy? (= 1 (send r get-selection))])
-                                         (send proxy-spec enable proxy?)
-                                         (if proxy?
-                                             (update-proxy)
-                                             (fw:preferences:set http-proxy-preference #f)))))]
-                    [proxy-spec (instantiate horizontal-panel% (p)
-                                             [stretchable-width #f]
-                                             [stretchable-height #f]
-                                             [alignment '(left center)])]
-                    [update-proxy (lambda ()
-                                    (let ([host (send host get-value)]
-                                          [port (send port get-value)])
-                                      (let ([ok? (and (regexp-match? #rx"^[-0-9a-zA-Z.]+$" host)
-                                                      (regexp-match? #rx"^[0-9]+$" port)
-                                                      (string->number port)
-                                                      (<= 1 (string->number port) 65535))])
-                                        (when ok?
-                                          (fw:preferences:set
-                                           http-proxy-preference
-                                           (list "http" host (string->number port))))
-                                        (send bad-host show (not ok?)))))]
-                    [host (make-object text-field%
-                                       (string-constant proxy-host)
-                                       proxy-spec (lambda (x y) (update-proxy))
-                                       "www.someplacethatisaproxy.domain.com")]
-                    [port (make-object text-field%
-                                       (string-constant proxy-port)
-                                       proxy-spec (lambda (x y) (update-proxy)) "65535")]
-                    [bad-host (make-object message%
-                                           (string-constant proxy-bad-host)
-                                           p)]
-                    [update-gui
-                     (lambda (proxy-val)
-                       (send bad-host show #f)
-                       (if proxy-val
-                           (begin
-                             (send rb set-selection 1)
-                             (send proxy-spec enable #t)
-                             (unless (string=? (cadr proxy-val) (send host get-value))
-                               (send host set-value (cadr proxy-val)))
-                             (unless (equal? (caddr proxy-val) (string->number (send port get-value)))
-                               (send port set-value (number->string (caddr proxy-val)))))
-                           (begin
-                             (send rb set-selection 0)
-                             (send proxy-spec enable #f)
-                             (send host set-value "")
-                             (send port set-value ""))))])
-
-             (fw:preferences:add-callback http-proxy-preference
-                                          (lambda (name val)
-                                            (update-gui val)))
-             (update-gui (fw:preferences:get http-proxy-preference))
-             (send bad-host show #f)))
-
-         (set! synchronized? #t)
-         (values pref-panel callbacks)))))
+       (define pref-panel
+         (new vertical-panel% [parent parent] [alignment '(left center)]))
+       
+       ;; -------------------- external browser for Unix --------------------
+       (when (unix-browser?)
+         (unless synchronized?
+           ;; Keep 'external-browser in sync
+           (fw:preferences:add-callback
+            'external-browser
+            (lambda (name browser) (try-put-preferences (list 'external-browser) (list browser)))))
+       
+         (letrec
+             ([v-panel (new group-box-panel%
+                            [parent pref-panel]
+                            [alignment '(right center)]
+                            [stretchable-height #f]
+                            [label (string-constant external-browser-choice-title)])]
+              [h-panel (new horizontal-panel% [parent v-panel] [alignment '(center bottom)])]
+              [none-index (length raw:unix-browser-list)]
+              [custom-index (add1 none-index)]
+              [r (new radio-box%
+                      [label #f]
+                      [choices
+                       (append unix-browser-names
+                               (list (string-constant no-browser)
+                                     (string-constant browser-command-line-label)))]
+                      [parent h-panel]
+                      [callback
+                       (lambda (radio event)
+                         (let ([n (send radio get-selection)])
+                           (set-browser! (cond
+                                           [(= n none-index) #f]
+                                           [(= n custom-index) (get-custom)]
+                                           [else (list-ref raw:unix-browser-list n)]))))])]
+              [select-custom (lambda (_ __)
+                               (send r set-selection custom-index)
+                               (set-browser! (get-custom)))]
+              [get-custom (lambda () (cons (send pre get-value) (send post get-value)))]
+              [template-panel (instantiate horizontal-panel% (h-panel)
+                                [spacing 0]
+                                [stretchable-height #f])]
+              [pre (instantiate text-field% ()
+                     [label #f]
+                     [parent template-panel]
+                     [callback select-custom]
+                     [horiz-margin 0])]
+              [mess (instantiate message% ()
+                      [label "<URL>"]
+                      [parent template-panel]
+                      [horiz-margin 0])]
+              [post (instantiate text-field% ()
+                      [label #f]
+                      [parent template-panel]
+                      [callback select-custom]
+                      [horiz-margin 0])]
+              [note1 (instantiate message% ((string-constant browser-cmdline-expl-line-1) v-panel))]
+              [note2 (instantiate message% ((string-constant browser-cmdline-expl-line-2) v-panel))]
+              [refresh-controls (lambda (pref)
+                                  (if (pair? pref)
+                                      (begin
+                                        (send r set-selection custom-index)
+                                        (send pre set-value (car pref))
+                                        (send post set-value (cdr pref)))
+                                      (let init ([x raw:unix-browser-list]
+                                                 [n 0])
+                                        (cond
+                                          [(null? x) (send r set-selection n)]
+                                          [else
+                                           (if (eq? pref (car x))
+                                               (send r set-selection n)
+                                               (init (cdr x)
+                                                     (add1 n)))]))))])
+       
+           (unless ask-later?
+             (send r enable none-index #f))
+       
+           (refresh-controls (fw:preferences:get 'external-browser))
+           (set! callbacks
+                 (cons (fw:preferences:add-callback 'external-browser
+                                                    (lambda (name browser)
+                                                      (refresh-controls browser)))
+                       callbacks))))
+       
+       ;; -------------------- proxy for doc downloads --------------------
+       (when set-help?
+         (letrec ([p (instantiate group-box-panel% ()
+                       [label (string-constant http-proxy)]
+                       [parent pref-panel]
+                       [stretchable-height #f]
+                       [alignment '(left top)])]
+                  [rb (make-object radio-box%
+                                   #f
+                                   (list (string-constant proxy-direct-connection)
+                                         (string-constant proxy-use-proxy))
+                                   p
+                                   (lambda (r e)
+                                     (let ([proxy? (= 1 (send r get-selection))])
+                                       (send proxy-spec enable proxy?)
+                                       (if proxy?
+                                           (update-proxy)
+                                           (fw:preferences:set http-proxy-preference #f)))))]
+                  [proxy-spec (instantiate horizontal-panel% (p)
+                                [stretchable-width #f]
+                                [stretchable-height #f]
+                                [alignment '(left center)])]
+                  [update-proxy (lambda ()
+                                  (let ([host (send host get-value)]
+                                        [port (send port get-value)])
+                                    (let ([ok? (and (regexp-match? #rx"^[-0-9a-zA-Z.]+$" host)
+                                                    (regexp-match? #rx"^[0-9]+$" port)
+                                                    (string->number port)
+                                                    (<= 1 (string->number port) 65535))])
+                                      (when ok?
+                                        (fw:preferences:set http-proxy-preference
+                                                            (list "http" host (string->number port))))
+                                      (send bad-host show (not ok?)))))]
+                  [host (make-object text-field%
+                                     (string-constant proxy-host)
+                                     proxy-spec
+                                     (lambda (x y) (update-proxy))
+                                     "www.someplacethatisaproxy.domain.com")]
+                  [port (make-object text-field%
+                                     (string-constant proxy-port)
+                                     proxy-spec
+                                     (lambda (x y) (update-proxy))
+                                     "65535")]
+                  [bad-host (make-object message% (string-constant proxy-bad-host) p)]
+                  [update-gui (lambda (proxy-val)
+                                (send bad-host show #f)
+                                (if proxy-val
+                                    (begin
+                                      (send rb set-selection 1)
+                                      (send proxy-spec enable #t)
+                                      (unless (string=? (cadr proxy-val) (send host get-value))
+                                        (send host set-value (cadr proxy-val)))
+                                      (unless (equal? (caddr proxy-val)
+                                                      (string->number (send port get-value)))
+                                        (send port set-value (number->string (caddr proxy-val)))))
+                                    (begin
+                                      (send rb set-selection 0)
+                                      (send proxy-spec enable #f)
+                                      (send host set-value "")
+                                      (send port set-value ""))))])
+       
+           (fw:preferences:add-callback http-proxy-preference (lambda (name val) (update-gui val)))
+           (update-gui (fw:preferences:get http-proxy-preference))
+           (send bad-host show #f)))
+       
+       (set! synchronized? #t)
+       (values pref-panel callbacks))))
diff --git a/drracket-test/tests/drracket/private/drracket-test-util.rkt b/drracket-test/tests/drracket/private/drracket-test-util.rkt
index 507729b50..77164c427 100644
--- a/drracket-test/tests/drracket/private/drracket-test-util.rkt
+++ b/drracket-test/tests/drracket/private/drracket-test-util.rkt
@@ -11,9 +11,8 @@
          "gui.rkt"
          "no-fw-test-util.rkt")
 
-  (provide/contract 
-   [use-get/put-dialog (-> (-> any) path? void?)]
-   [set-module-language! (->* () (boolean?) void?)])
+  (provide (contract-out [use-get/put-dialog (-> (-> any) path? void?)]
+                         [set-module-language! (->* () (boolean?) void?)]))
   
   (provide queue-callback/res
            fire-up-drracket-and-run-tests
@@ -60,25 +59,25 @@
   ;; filename is a string naming a file that should be typed into the dialog
   (define (use-get/put-dialog open-dialog filename)
     (not-on-eventspace-handler-thread 'use-get/put-dialog)
-    (let ([drs (wait-for-drracket-frame)])
-      (with-handlers ([(lambda (x) #t)
-		       (lambda (x)
-			 (fw:preferences:set 'framework:file-dialogs 'std)
-			 (raise x))])
-	(fw:preferences:set 'framework:file-dialogs 'common)
-	(open-dialog)
-	(let ([dlg (wait-for-new-frame drs)])
-	  (send (find-labelled-window "Filename:" #f (fw:test:get-active-top-level-window)) focus)
-	  (fw:test:keystroke #\a (list (case (system-type)
-					 [(windows) 'control]
-					 [(macosx macos) 'meta]
-					 [(unix) 'control]
-                                         [else (error 'use-get/put-dialog "unknown platform: ~s\n"
-                                                      (system-type))])))
-	  (for-each fw:test:keystroke (string->list (path->string filename)))
-	  (fw:test:button-push "OK")
-	  (wait-for-new-frame dlg))
-	(fw:preferences:set 'framework:file-dialogs 'std))))
+    (define drs (wait-for-drracket-frame))
+    (with-handlers ([(lambda (x) #t) (lambda (x)
+                                       (fw:preferences:set 'framework:file-dialogs 'std)
+                                       (raise x))])
+      (fw:preferences:set 'framework:file-dialogs 'common)
+      (open-dialog)
+      (let ([dlg (wait-for-new-frame drs)])
+        (send (find-labelled-window "Filename:" #f (fw:test:get-active-top-level-window)) focus)
+        (fw:test:keystroke
+         #\a
+         (list (case (system-type)
+                 [(windows) 'control]
+                 [(macosx macos) 'meta]
+                 [(unix) 'control]
+                 [else (error 'use-get/put-dialog "unknown platform: ~s\n" (system-type))])))
+        (for-each fw:test:keystroke (string->list (path->string filename)))
+        (fw:test:button-push "OK")
+        (wait-for-new-frame dlg))
+      (fw:preferences:set 'framework:file-dialogs 'std)))
 
   (define (test-util-error fmt . args)
     (raise (make-exn (apply fmt args) (current-continuation-marks))))
@@ -90,10 +89,7 @@
   (define (wait-for-drracket-frame [print-message? #f])
     (define (wait-for-drracket-frame-pred)
       (define active (fw:test:get-active-top-level-window))
-      (if (and active
-               (drracket-frame? active))
-          active
-          #f))
+      (and (and active (drracket-frame? active)) active))
     (define drr-fr
       (or (wait-for-drracket-frame-pred)
           (begin
@@ -116,10 +112,7 @@
                          (for/or ([eventspace (in-list extra-eventspaces)]) 
                            (parameterize ([current-eventspace eventspace])
                              (fw:test:get-active-top-level-window)))))
-      (if (and active
-               (not (eq? active old-frame)))
-          active
-          #f))
+      (and (and active (not (eq? active old-frame))) active))
     (define lab (send old-frame get-label))
     (define fr (poll-until 
                 (procedure-rename wait-for-new-frame-pred
@@ -167,34 +160,29 @@
     (poll-until wait-for-computation-to-finish 60)
     (sync (system-idle-evt)))
 
-  (define do-execute 
-    (case-lambda
-     [(frame)
-      (do-execute frame #t)]
-     [(frame wait-for-finish?)
-      (not-on-eventspace-handler-thread 'do-execute)
-      (queue-callback/res (λ () (verify-drracket-frame-frontmost 'do-execute frame)))
-      (let ([button (queue-callback/res (λ () (send frame get-execute-button)))])
-	(fw:test:run-one (lambda () (send button command)))
-	(when wait-for-finish?
-          (wait-for-computation frame)))]))
+  (define (do-execute frame [wait-for-finish? #t])
+    (not-on-eventspace-handler-thread 'do-execute)
+    (queue-callback/res (λ () (verify-drracket-frame-frontmost 'do-execute frame)))
+    (let ([button (queue-callback/res (λ () (send frame get-execute-button)))])
+      (fw:test:run-one (lambda () (send button command)))
+      (when wait-for-finish?
+        (wait-for-computation frame))))
   
   (define (verify-drracket-frame-frontmost function-name frame)
     (on-eventspace-handler-thread 'verify-drracket-frame-frontmost)
-    (let ([tl (fw:test:get-active-top-level-window)])
-      (unless (and (eq? frame tl)
-                   (drracket-frame? tl))
-        (error function-name "drracket frame not frontmost: ~e (found ~e)" frame tl))))
+    (define tl (fw:test:get-active-top-level-window))
+    (unless (and (eq? frame tl) (drracket-frame? tl))
+      (error function-name "drracket frame not frontmost: ~e (found ~e)" frame tl)))
   
   (define (clear-definitions frame)
     (queue-callback/res (λ () (verify-drracket-frame-frontmost 'clear-definitions frame)))
     (fw:test:new-window (queue-callback/res (λ () (send frame get-definitions-canvas))))
     (let ([window (queue-callback/res (λ () (send frame get-edit-target-window)))])
-      (let-values ([(cw ch) (queue-callback/res (λ () (send window get-client-size)))]
-                   [(w h) (queue-callback/res (λ () (send window get-size)))])
-        (fw:test:mouse-click 'left
-			     (inexact->exact (floor (+ cw (/ (- w cw) 2))))
-			     (inexact->exact (floor (+ ch (/ (- h ch) 2)))))))
+      (define-values (cw ch) (queue-callback/res (λ () (send window get-client-size))))
+      (define-values (w h) (queue-callback/res (λ () (send window get-size))))
+      (fw:test:mouse-click 'left
+                           (inexact->exact (floor (+ cw (/ (- w cw) 2))))
+                           (inexact->exact (floor (+ ch (/ (- h ch) 2))))))
     (fw:test:menu-select "Edit" "Select All")
     (fw:test:menu-select "Edit" (if (eq? (system-type) 'macos)
 				    "Clear"
@@ -217,29 +205,29 @@
     (not-on-eventspace-handler-thread 'put-in-frame)
     (unless (and (object? frame) (is-a? frame top-level-window<%>))
       (error who "expected a frame or a dialog as the first argument, got ~e" frame))
-    (let ([str (if (string? str/sexp)
-		   str/sexp
-		   (let ([port (open-output-string)])
-		     (parameterize ([current-output-port port])
-		       (write str/sexp port))
-		     (get-output-string port)))])
-      (queue-callback/res (λ () (verify-drracket-frame-frontmost who frame)))
-      (let ([canvas (queue-callback/res (λ () (get-canvas frame)))])
-	(fw:test:new-window canvas)
-	(let ([editor (queue-callback/res (λ () (send canvas get-editor)))])
-          (cond
-            [just-insert? 
-             (let ([s (make-semaphore 0)])
-               (queue-callback
-                (λ () 
-                  (send editor set-caret-owner #f)
-                  (send editor insert str)
-                  (semaphore-post s)))
-               (unless (sync/timeout 3 s)
-                 (error who "callback didn't run for 3 seconds; trying to insert ~s" str/sexp)))]
-            [else 
-             (queue-callback/res (λ () (send editor set-caret-owner #f)))
-             (type-string str)])))))
+    (define str
+      (if (string? str/sexp)
+          str/sexp
+          (let ([port (open-output-string)])
+            (parameterize ([current-output-port port])
+              (write str/sexp port))
+            (get-output-string port))))
+    (queue-callback/res (λ () (verify-drracket-frame-frontmost who frame)))
+    (define canvas (queue-callback/res (λ () (get-canvas frame))))
+    (fw:test:new-window canvas)
+    (define editor (queue-callback/res (λ () (send canvas get-editor))))
+    (cond
+      [just-insert?
+       (let ([s (make-semaphore 0)])
+         (queue-callback (λ ()
+                           (send editor set-caret-owner #f)
+                           (send editor insert str)
+                           (semaphore-post s)))
+         (unless (sync/timeout 3 s)
+           (error who "callback didn't run for 3 seconds; trying to insert ~s" str/sexp)))]
+      [else
+       (queue-callback/res (λ () (send editor set-caret-owner #f)))
+       (type-string str)]))
   
   (define (alt-return-in-interactions frame)
     (not-on-eventspace-handler-thread 'alt-return-in-interactions)
@@ -450,7 +438,7 @@
                      new-frame
                      drs-frame)))))))
   
-  (provide/contract [check-language-level ((or/c string? regexp?) . -> . void?)])
+  (provide (contract-out [check-language-level ((or/c string? regexp?) . -> . void?)]))
   ;; checks that the language in the drracket window is set to the given one.
   ;; clears the definitions, clicks execute and checks the interactions window.
   (define (check-language-level lang-spec)
diff --git a/drracket/gui-debugger/debug-tool.rkt b/drracket/gui-debugger/debug-tool.rkt
index 722ddee82..7a5f94f7d 100644
--- a/drracket/gui-debugger/debug-tool.rkt
+++ b/drracket/gui-debugger/debug-tool.rkt
@@ -486,26 +486,26 @@
           (when (and (send (get-tab) debug?) (not before))
             ;; render breakpoints
             (let ([breakpoints (send (get-tab) get-breakpoints)])
-              (for ([(pos enabled?) (in-hash breakpoints)])
-                (when (and (>= pos 0) (or enabled? (and mouse-over-pos (= mouse-over-pos pos))))
-                  (define-values (xl yl xr yr) (find-char-box this pos))
-                  (define diameter (- xr xl))
-                  (define yoff (/ (- yr yl diameter) 2))
-                  (define op (send dc get-pen))
-                  (define ob (send dc get-brush))
-                  (case enabled?
-                    [(#t)
-                     (send dc set-pen bp-pen)
-                     (send dc set-brush bp-brush)]
-                    [(#f)
-                     (send dc set-pen bp-mo-pen)
-                     (send dc set-brush bp-mo-brush)]
-                    [else
-                     (send dc set-pen bp-tmp-pen)
-                     (send dc set-brush bp-tmp-brush)])
-                  (send dc draw-ellipse (+ xl dx) (+ yl dy yoff) diameter diameter)
-                  (send dc set-pen op)
-                  (send dc set-brush ob))))
+              (for ([(pos enabled?) (in-hash breakpoints)]
+                    #:when (and (>= pos 0) (or enabled? (and mouse-over-pos (= mouse-over-pos pos)))))
+                (define-values (xl yl xr yr) (find-char-box this pos))
+                (define diameter (- xr xl))
+                (define yoff (/ (- yr yl diameter) 2))
+                (define op (send dc get-pen))
+                (define ob (send dc get-brush))
+                (case enabled?
+                  [(#t)
+                   (send dc set-pen bp-pen)
+                   (send dc set-brush bp-brush)]
+                  [(#f)
+                   (send dc set-pen bp-mo-pen)
+                   (send dc set-brush bp-mo-brush)]
+                  [else
+                   (send dc set-pen bp-tmp-pen)
+                   (send dc set-brush bp-tmp-brush)])
+                (send dc draw-ellipse (+ xl dx) (+ yl dy yoff) diameter diameter)
+                (send dc set-pen op)
+                (send dc set-brush ob)))
             ;; mark the boundaries of the current stack frame
             ;; unless we're at the end of the expression and looking at the top frame,
             ;; in which case just mark the current location
@@ -1234,21 +1234,20 @@
         
         (define/public (register-stack-frames frames already-stopped?)
           (define trimmed-exprs
-            (map (lambda (frame)
-                   (let ([expr (mark-source frame)])
-                     (cond
-                       ; should succeed unless the user closes a secondary tab during debugging
-                       [(and expr (filename->defs (syntax-source expr)))
-                        =>
-                        (lambda (defs)
-                          (trim-expr-str (if (syntax-position expr)
-                                             (send defs get-text
-                                                   (sub1 (syntax-position expr))
-                                                   (+ -1 (syntax-position expr) (syntax-span expr)))
-                                             "??")
-                                         15))]
-                       ["??"])))
-                 frames))
+            (for/list ([frame (in-list frames)])
+              (define expr (mark-source frame))
+              (cond
+                ; should succeed unless the user closes a secondary tab during debugging
+                [(and expr (filename->defs (syntax-source expr)))
+                 =>
+                 (lambda (defs)
+                   (trim-expr-str (if (syntax-position expr)
+                                      (send defs get-text
+                                            (sub1 (syntax-position expr))
+                                            (+ -1 (syntax-position expr) (syntax-span expr)))
+                                      "??")
+                                  15))]
+                ["??"])))
           (send stack-frames begin-edit-sequence)
           (send stack-frames lock #f)
           (unless already-stopped?