application-file-handler no longer works on Windows

[default-kramer]

On Windows, the following functionality worked with 7.7 but has since been broken. To reproduce:

Save the following file as afh.rkt

#lang racket/gui

(application-file-handler
 (lambda args
   (println (list "afh was called!" args))))

(println (list "entered afh.rkt" (current-command-line-arguments)))

(module+ main
  (define frame (new frame% [label "afh test"]))
  (send frame show #t))

Now run the following script to create test.exe

#lang racket/base

(require launcher)

(make-gracket-launcher
 (list "full-path-to\\afh.rkt") ; !!! put your path here !!!
 "test.exe"
 '((single-instance? . #t)))

Now from cmd.exe run the following two commands

> test.exe one two
> test.exe three four

On Racket 7.7, a single application is run and produced the following console output:

'("entered afh.rkt" #("one" "two"))
'("afh was called!" (#<path:three>))
'("afh was called!" (#<path:four>))

But on Racket 8.2, the second execution of test.exe seemingly does nothing. The output is only

'("entered afh.rkt" #("one" "two"))

It's very likely that this was broken with 7.8 based on comments of racket/drracket#456

[mflatt]

Thanks for helping tracking this down with that example!