syntax-local-get-shadower: fix interaction with marked bindings

Getting a shadower should not drop module context if the context
determines a binding that has marks.

collects/tests/racket/macro.rktl

@@ -803,6 +803,31 @@
   (test (list #t #t) map syntax-original? r/ls)
   (test (list #t #t) map number? (map syntax-position r/ls)))
 
+;; ----------------------------------------
+
+(module check-shadower-in-submodule racket/base
+  (require (for-syntax racket/base))
+  
+  (define-syntax (define-2 stx)
+    (syntax-case stx () 
+      [(_ id)
+       (with-syntax ([new-id
+                      ((make-syntax-introducer)
+                       (datum->syntax #f
+                                      (string->symbol
+                                       (format "~a2" (syntax-e #'id)))))])
+         #'(begin
+             (define new-id 5)
+             (define-syntax (id stx)
+               (syntax-local-get-shadower #'new-id))))]))
+  
+  (module* main #f
+    (provide out)
+    (define-2 f)
+    (define f2 6)
+    (define out f)))
+
+(test 5 dynamic-require '(submod 'check-shadower-in-submodule main) 'out)
 
 ;; ----------------------------------------
 

src/racket/src/env.c

@@ -2278,6 +2278,11 @@ local_get_shadower(int argc, Scheme_Object *argv[])
   uid = scheme_find_local_shadower(sym, sym_marks, env);
 
   if (!uid) {
+    uid = scheme_tl_id_sym(env->genv, sym, NULL, 0, 
+                           scheme_make_integer(env->genv->phase), NULL);
+    if (!SAME_OBJ(uid, SCHEME_STX_VAL(sym))) {
+      /* has a toplevel biding via marks or context; keep it */
+    } else {
       /* No lexical shadower, but strip module context, if any */
       sym = scheme_stx_strip_module_context(sym);
       /* Add current module context, if any */
@@ -2285,6 +2290,7 @@ local_get_shadower(int argc, Scheme_Object *argv[])
 
       if (!scheme_stx_is_clean(orig_sym))
         sym = scheme_stx_taint(sym);
+    }
 
     return sym;
   }