cocoa: fix problems with frame-list management

collects/mred/private/wx/cocoa/frame.rkt

@@ -36,6 +36,9 @@
 (define empty-mb (new menu-bar%))
 (define root-fake-frame #f)
 
+;; Maps window numbers to weak boxes of frame objects;
+;;  the weak-box layer is needed to avoid GC-accounting
+;;  problems.
 (define all-windows (make-hash))
 
 (define-objc-mixin (MyWindowMethods Superclass)
@@ -278,7 +281,7 @@
       (register-frame-shown this on?)
       (let ([num (tell #:type _NSInteger cocoa windowNumber)])
         (if on?
-            (hash-set! all-windows num this)
+            (hash-set! all-windows num (make-weak-box this))
             (hash-remove! all-windows num)))
       (when on?
         (let ([b (eventspace-wait-cursor-count (get-eventspace))])
@@ -534,9 +537,13 @@
                  (let ([f (tell #:type _NSRect (tell NSScreen mainScreen) frame)])
                    (make-NSPoint x (- (NSSize-height (NSRect-size f)) y)))
                  belowWindowWithWindowNumber: #:type _NSInteger 0)])
-    (atomically (hash-ref all-windows n #f))))
+    (atomically (let ([b (hash-ref all-windows n #f)])
+                  (and b (weak-box-value b))))))
 
 (set-fixup-window-locations!
  (lambda ()
-   (for ([f (in-hash-values all-windows)])
-     (send f fixup-locations-children))))
+   ;; in atomic mode
+   (for ([b (in-hash-values all-windows)])
+     (let ([f (weak-box-value b)])
+       (send f fixup-locations-children)))))
+

collects/mred/private/wx/cocoa/printer-dc.rkt

@@ -12,6 +12,7 @@
          ffi/unsafe/objc
          "../../lock.rkt"
          "dc.rkt"
+         "frame.rkt"
          "bitmap.rkt"
          "cg.rkt"
          "utils.rkt"
@@ -101,8 +102,13 @@
                              (send pss set-native pi make-print-info)
                              pi)))])
     (install-pss-to-print-info pss print-info)
-    (if (= (tell #:type _NSInteger (tell NSPageLayout pageLayout) runModalWithPrintInfo: print-info)
+    (if (atomically
+         (let ([front (get-front)])
+           (begin0
+            (= (tell #:type _NSInteger (tell NSPageLayout pageLayout) runModalWithPrintInfo: print-info)
                NSOkButton)
+            (when front
+              (tellv (send front get-cocoa-window) makeKeyAndOrderFront: #f)))))
         (begin
           (let ([o (tell #:type _int print-info orientation)])
             (send pss set-orientation (if (= o NSLandscapeOrientation)
@@ -195,4 +201,8 @@
 
       (set-ivar! view-cocoa wxb (->wxb this))
 
-      (tellv op-cocoa runOperation))))
+      (atomically
+       (let ([front (get-front)])
+         (tellv op-cocoa runOperation)
+         (when front
+           (tellv (send front get-cocoa-window) makeKeyAndOrderFront: #f)))))))