From ccda0e4abbdd5e72d03f0fcae6cbcc9261c6e0a4 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 25 Jul 2014 07:20:28 +0100
Subject: [PATCH] macro expander: fix `identifier-binding` on fully expanded
 module

Fix the case of an identifier that is used as a binding in a module
but originated from a different module.
---
 .../racket-test/tests/racket/submodule.rktl   | 27 +++++++++++++++++++
 racket/src/racket/src/syntax.c                | 10 ++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/pkgs/racket-pkgs/racket-test/tests/racket/submodule.rktl b/pkgs/racket-pkgs/racket-test/tests/racket/submodule.rktl
index 111fbccefa..72fed9025b 100644
--- a/pkgs/racket-pkgs/racket-test/tests/racket/submodule.rktl
+++ b/pkgs/racket-pkgs/racket-test/tests/racket/submodule.rktl
@@ -920,6 +920,33 @@
 
 (test 'yes dynamic-require ''uses-id-not-id* 'answer)
 
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Check binding in fully expanded module:
+
+(let ()
+  (define m
+    '(module m racket/kernel
+       (module foo racket
+         (provide def-wrap)
+         (define-syntax-rule (def-wrap)
+           (begin  (define y 1) y)))
+       (module bar racket/kernel
+         (#%require (submod ".." foo))
+         (def-wrap))))
+
+  (parameterize ([current-namespace (make-base-namespace)])
+    (define e (expand m))
+    ;; (pretty-print (syntax->datum e))
+    (syntax-case e (module)
+      [(module m _
+         (#%mb1
+          _
+          (module bar _
+            (#%mb2
+             (#%require (submod ".." foo))
+             (define-values (y) '1)
+             _))))
+       (test #t list? (identifier-binding #'y))])))
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
diff --git a/racket/src/racket/src/syntax.c b/racket/src/racket/src/syntax.c
index ab0e7cc7c5..128f97dbe5 100644
--- a/racket/src/racket/src/syntax.c
+++ b/racket/src/racket/src/syntax.c
@@ -3097,6 +3097,7 @@ static Scheme_Object *get_old_module_env(Scheme_Object *stx)
   WRAP_POS awl;
   Scheme_Object *a, *last_id = NULL, *cancel_rename_id = scheme_false;
   Scheme_Object *result_id = scheme_false, *last_pr = NULL, *pr;
+  int saw_rename = 0;
 
   WRAP_POS_INIT(awl, ((Scheme_Stx *)stx)->wraps);
 
@@ -3155,13 +3156,20 @@ static Scheme_Object *get_old_module_env(Scheme_Object *stx)
         }
         last_id = set_identity;
       }
+
+      /* Only cancel via phase shift after we've seen a rename.
+         Canceling makes submodule contexts work, while not canceling
+         until after a rename makes inspection of a fully-expanded
+         module work in the case that a binding's indentifier cam from
+         another module. */
+      saw_rename = 1;
     } else if (SCHEME_BOXP(a)) {
       /* Phase shift: */
       Scheme_Object *vec;
 
       vec = SCHEME_BOX_VAL(a);
       a = SCHEME_VEC_ELS(vec)[5];
-      if (!SCHEME_FALSEP(a))
+      if (saw_rename && !SCHEME_FALSEP(a))
         cancel_rename_id = a;
     }