From 2b861d3e67fd01939438f75d600000d009570105 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Mon, 5 Sep 2011 16:08:16 -0600
Subject: [PATCH] generalized `begin-for-syntax'

original commit: d3c56c9f13327d07513f8b6bf7ea0230acb7f489
---
 collects/mzlib/include.rkt         |  5 +++-
 collects/racket/private/old-rp.rkt | 45 +++++++++++++++---------------
 2 files changed, 27 insertions(+), 23 deletions(-)

diff --git a/collects/mzlib/include.rkt b/collects/mzlib/include.rkt
index 356f326..350efea 100644
--- a/collects/mzlib/include.rkt
+++ b/collects/mzlib/include.rkt
@@ -20,7 +20,10 @@
 		   fn))
 		(string->path s))]
 	     [(-build-path elem ...)
-	      (module-or-top-identifier=? #'-build-path build-path-stx)
+              (begin
+                (collect-garbage)
+                (module-identifier=? #'-build-path build-path-stx)
+                (module-or-top-identifier=? #'-build-path build-path-stx))
 	      (let ([l (syntax-object->datum (syntax (elem ...)))])
 		(when (null? l)
 		  (raise-syntax-error
diff --git a/collects/racket/private/old-rp.rkt b/collects/racket/private/old-rp.rkt
index 74f1554..14b78db 100644
--- a/collects/racket/private/old-rp.rkt
+++ b/collects/racket/private/old-rp.rkt
@@ -5,28 +5,29 @@
   (#%provide require require-for-syntax require-for-template require-for-label
              provide provide-for-syntax provide-for-label)
 
-  (define-values-for-syntax (rebuild-elem)
-    (lambda (stx elem sub pos loop ids)
-      ;; For sub-forms, we loop and reconstruct:
-      (for-each (lambda (id)
-                  (unless (identifier? id)
-                    (raise-syntax-error
-                     #f
-                     "expected an identifier"
-                     stx
-                     id)))
-                (syntax->list ids))
-      (let rloop ([elem elem][pos pos])
-        (if (syntax? elem)
-            (datum->syntax elem
-                                  (rloop (syntax-e elem) pos)
-                                  elem
-                                  elem)
-            (if (zero? pos)
-                (cons (loop (car elem))
-                      (cdr elem))
-                (cons (car elem)
-                      (rloop (cdr elem) (sub1 pos))))))))
+  (begin-for-syntax
+   (define-values (rebuild-elem)
+     (lambda (stx elem sub pos loop ids)
+       ;; For sub-forms, we loop and reconstruct:
+       (for-each (lambda (id)
+                   (unless (identifier? id)
+                     (raise-syntax-error
+                      #f
+                      "expected an identifier"
+                      stx
+                      id)))
+                 (syntax->list ids))
+       (let rloop ([elem elem][pos pos])
+         (if (syntax? elem)
+             (datum->syntax elem
+                            (rloop (syntax-e elem) pos)
+                            elem
+                            elem)
+             (if (zero? pos)
+                 (cons (loop (car elem))
+                       (cdr elem))
+                 (cons (car elem)
+                       (rloop (cdr elem) (sub1 pos)))))))))
 
 
   (define-syntaxes (require require-for-syntax require-for-template require-for-label)