fix variable-reference->namespace for phase > 0

Set up bindings and shift phases as needed to make
`variable-reference->namespace` work in a run-time position when the
enclosing module is instantiated at a phase other than 0.

Thanks to Rohin Shah for the bug report.

pkgs/racket-test-core/tests/racket/module.rktl

@@ -1937,6 +1937,74 @@ case of module-leve bindings; it doesn't cover local bindings.
             (provide x))
           (require 'a-submod)))
 
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Make sure that `variable-reference->namespace` works
+;; with phase shifts
+
+(module evaluate-using-module-namespace racket/base
+  (provide go)
+
+  (define x 'x)
+
+  (define (go)
+    (define ns (variable-reference->namespace (#%variable-reference)))
+    (list (namespace-base-phase ns)
+          (eval '(list x) ns))))
+
+(test '(0 (x)) (dynamic-require ''evaluate-using-module-namespace 'go))
+
+(module evaluate-using-module-namespace-at-phase-1 racket/base
+  (require (for-syntax 'evaluate-using-module-namespace
+                       racket/base))
+  (provide went)
+  (define-syntax (m stx)
+    #`(quote #,(go)))
+  (define (went) (m)))
+
+(test '(1 (x)) (dynamic-require ''evaluate-using-module-namespace-at-phase-1 'went))
+
+(module evaluate-using-module-namespace/saved-context racket/base
+  (provide go)
+
+  (define x 'x/sc)
+
+  ;; Macro-introduced definition triggers saving the module's bindings
+  (define-syntax-rule (force-save-context) (define x 1))
+  (force-save-context)
+
+  (define (go)
+    (define ns (variable-reference->namespace (#%variable-reference)))
+    (list (namespace-base-phase ns)
+          (eval '(list x) ns))))
+
+(test '(0 (x/sc)) (dynamic-require ''evaluate-using-module-namespace/saved-context 'go))
+
+(module evaluate-using-module-namespace-at-phase-1/saved-context racket/base
+  (require (for-syntax 'evaluate-using-module-namespace/saved-context
+                       racket/base))
+  (provide went)
+  (define-syntax (m stx)
+    #`(quote #,(go)))
+  (define (went) (m)))
+
+(test '(1 (x/sc)) (dynamic-require ''evaluate-using-module-namespace-at-phase-1/saved-context 'went))
+
+
+(module defines-a-variable-x-in-its-body racket/base
+  (define x 'defined))
+
+(module uses-defines-a-variable-x-in-its-body-at-phase-1 racket/base
+  (require (for-syntax racket/base))
+  (provide out)
+  
+  (define-syntax (m stx)
+    (dynamic-require ''defines-a-variable-x-in-its-body #f)
+    #`(quote #,(eval 'x (module->namespace ''defines-a-variable-x-in-its-body))))
+  
+  (define out (m)))
+
+(test 'defined dynamic-require ''uses-defines-a-variable-x-in-its-body-at-phase-1 'out)
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (report-errs)

racket/src/racket/src/env.c

@@ -2121,7 +2121,7 @@ static Scheme_Object *do_variable_namespace(const char *who, int tl, int argc, S
     return env->access_insp;
   } else if (tl) {
     /* return env directly; need to set up  */
-    if (!env->phase && env->module)
+    if (!env->mod_phase && env->module)
       scheme_prep_namespace_rename(env);
     env->interactive_bindings = 1;
   } else {

racket/src/racket/src/module.c

@@ -3237,6 +3237,7 @@ void scheme_prep_namespace_rename(Scheme_Env *menv)
         }
 	
 	rns = scheme_module_context_to_stx(rns, NULL);
+
 	m->rn_stx = rns;
       } else if (SCHEME_PAIRP(m->rn_stx)) {
 	/* Delayed shift: */
@@ -3257,7 +3258,11 @@ void scheme_prep_namespace_rename(Scheme_Env *menv)
         m->rn_stx = rn_stx;
       }
 
-      rns = scheme_stx_to_module_context(m->rn_stx);
+      rns = m->rn_stx;
+      if (menv->phase)
+        rns = scheme_stx_shift(rns, scheme_make_integer(menv->phase), NULL, NULL, NULL, NULL, NULL);
+
+      rns = scheme_stx_to_module_context(rns);
       menv->stx_context = rns;
 
       menv->rename_set_ready = 1;