From 33f3574f7e6374e70c4abac326c8227570039749 Mon Sep 17 00:00:00 2001
From: Ryan Culpepper <ryanc@racket-lang.org>
Date: Mon, 3 Dec 2012 18:54:34 -0500
Subject: [PATCH] fix lazy-require for local submod module-paths

---
 collects/racket/lazy-require.rkt | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/collects/racket/lazy-require.rkt b/collects/racket/lazy-require.rkt
index f8a58b6619..6c638aacb3 100644
--- a/collects/racket/lazy-require.rkt
+++ b/collects/racket/lazy-require.rkt
@@ -12,6 +12,29 @@
 
 (define-for-syntax counter 0)
 
+(begin-for-syntax
+ ;; like (collapse-module-path modpath '(submod "..")), but avoids
+ ;; the dependencies of syntax/modcollapse
+ (define (module-path-add-submod-up modpath)
+   (let ([d (syntax->list modpath)])
+     (cond [(and d (list? d) (>= (length d) 2) (eq? (syntax-e (car d)) 'submod))
+            ;; was a submod module-path
+            (let ([parts (cdr d)]) ;; length >= 1
+              (cond [(or (equal? (syntax-e (car parts)) ".")
+                         (equal? (syntax-e (car parts)) ".."))
+                     ;; (submod "." part ...) => (submod "." ".." part ...)
+                     ;; (submod ".." part ...) => (submod ".." ".." part ...)
+                     (datum->syntax modpath
+                                    (list* (car d) (car parts) ".." (cdr parts))
+                                    modpath)]
+                    [else
+                     ;; wasn't relative
+                     ;; FIXME: what about 'mod = (submod "." mod) abbreviation?
+                     modpath]))]
+           [else
+            ;; wasn't a submod module-path
+            modpath]))))
+
 (define-syntax (lazy-require1 stx)
   (syntax-case stx ()
     [(lazy-require1 modpath (name ...) orig-stx)
@@ -36,14 +59,18 @@
                                           (string->symbol
                                            (format "lazy-require-path-~a-~a" 
                                                    phase
-                                                   counter))])
+                                                   counter))]
+                                         ;; May need to adjust modpath, since we're interpreting it
+                                         ;; relative to a *submodule* of the original context.
+                                         ;; ie, module-path interpretation is not hygienic!
+                                         [modpath* (module-path-add-submod-up #'modpath)])
                              (set! counter (add1 counter))
                              #'(begin
                                  (module lazy-require-path-n racket/base
                                    (require racket/runtime-path
                                             (for-syntax racket/base))
                                    (provide mpi-var)
-                                   (define-runtime-module-path-index mpi-var (quote modpath)))
+                                   (define-runtime-module-path-index mpi-var (quote modpath*)))
                                  (require 'lazy-require-path-n)))))])
        #'(begin 
            define-mpi-var