Index: cfe/trunk/lib/Sema/SemaDecl.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp
+++ cfe/trunk/lib/Sema/SemaDecl.cpp
@@ -6935,7 +6935,7 @@
         }
     }
 
-  DeclContext *OldDC = ShadowedDecl->getDeclContext();
+  DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();
 
   unsigned WarningDiag = diag::warn_decl_shadow;
   SourceLocation CaptureLoc;
Index: cfe/trunk/test/SemaCXX/warn-shadow.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/warn-shadow.cpp
+++ cfe/trunk/test/SemaCXX/warn-shadow.cpp
@@ -206,3 +206,10 @@
 }
 
 }
+
+extern "C" {
+typedef int externC; // expected-note {{previous declaration is here}}
+}
+void handleLinkageSpec() {
+  typedef void externC; // expected-warning {{declaration shadows a typedef in the global namespace}}
+}