better behavior with unsaved DrRacket files

quad/quadwriter/lang-helper.rkt

@@ -74,19 +74,19 @@
                       [else (error "Unknown platform. Don't know how to view PDF.")]))
                   (void (system (format open-string pdf-path)))))
 
-              (define (make-pdf [pdf-path #false])
+              (define (make-pdf [the-pdf-path #false])
                 (with-logging-to-port
                  (current-output-port)
                  (λ () (with-logging-to-port
                         (current-output-port)
-                        (λ () (render-pdf DOC pdf-path))
+                        (λ () (render-pdf DOC the-pdf-path))
                         #:logger quadwriter-logger
                         'debug))
                  #:logger quad-logger
                  'debug))
 
               (module+ pdf
-                (define pdf (make-pdf))
+                (define pdf (make-pdf pdf-path))
                 (provide pdf))
               
               (module+ main

quad/quadwriter/render.rkt

@@ -213,10 +213,14 @@
     #:replace any/c
     #:compress any/c) . ->* . (or/c void? bytes?))
 
-  (define base-dir (match base-dir-arg
-                     [#false (current-directory)]
-                     [path (define-values (dir name _) (split-path path))
-                           dir]))
+  (match-define-values (base-dir _ _) (split-path
+                                       (match base-dir-arg
+                                         [#false (current-directory)]
+                                         ;; for reasons unclear, DrRacket sometimes sneaks
+                                         ;; an "unsaved editor" into this arg, despite efforts to prevent
+                                         ;; probably 
+                                         ["unsaved editor" pdf-path-arg]
+                                         [path path])))
 
   (define pdf-path (setup-pdf-path pdf-path-arg))
   (unless replace-existing-file?