fulfill a promise

quad/quad/scribblings/quad.scrbl

@@ -664,7 +664,7 @@ TK: OT feature attributes, bullet attributes
 [#:replace replace? any/c #true]
 [#:compress compress? any/c #true])
 (or/c void? bytes?)]{
-Compute the layout for @racket[qx] and render it as a PDF to @racket[pdf-path]. If @racket[pdf-path] is @racket[#false], then the rendered PDF is returned as a @tech[#:doc '(lib "scribblings/guide/guide.scrbl")]{byte string}. Otherwise it is written to @racket[pdf-path].
+Compute the layout for @racket[qx] and render it as a PDF to @racket[pdf-path]. If @racket[pdf-path] is @racket[#false], then the rendered PDF is returned as a @tech[#:doc '(lib "scribblings/guide/guide.scrbl")]{byte string}. Otherwise it is written to @racket[pdf-path]. The default is @racket[#false].
 
 The optional @racket[base-dir] argument sets a base directory for resolution of any relative path names passed as attribute values. The default is @racket[(current-directory)]. 
 

quad/quadwriter/render.rkt

@@ -201,12 +201,14 @@
 
 (define (footnote-flow? q) (equal? (quad-ref q 'flow) "footnote"))
 
-(define/contract (render-pdf qx-arg pdf-path-arg
+(define/contract (render-pdf qx-arg
+                             [pdf-path-arg #false]
                              [base-dir-arg #false]
                              #:replace [replace-existing-file? #t]
                              #:compress [compress? #t])
-  ((qexpr? (or/c #false path? path-string?))
+  ((qexpr?)
    ((or/c #false path? path-string?)
+    (or/c #false path? path-string?)
     #:replace any/c
     #:compress any/c) . ->* . (or/c void? bytes?))