2 files changed, 44 insertions, 8 deletions

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index df9fdeb40d..ebe2894406 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -884,6 +884,8 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
   //   }
   // }
   //
+  UnqualUsingDirectiveSet UDirs;
+  bool VisitedUsingDirectives = false;
   DeclContext *OutsideOfTemplateParamDC = 0;
   for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
     DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
@@ -957,9 +959,24 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
         // If this is a file context, we need to perform unqualified name
         // lookup considering using directives.
         if (Ctx->isFileContext()) {
-          UnqualUsingDirectiveSet UDirs;
-          UDirs.visit(Ctx, Ctx);
-          UDirs.done();
+          // If we haven't handled using directives yet, do so now.
+          if (!VisitedUsingDirectives) {
+            // Add using directives from this context up to the top level.
+            for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent())
+              UDirs.visit(UCtx, UCtx);
+
+            // Find the innermost file scope, so we can add using directives
+            // from local scopes.
+            Scope *InnermostFileScope = S;
+            while (InnermostFileScope &&
+                   !isNamespaceOrTranslationUnitScope(InnermostFileScope))
+              InnermostFileScope = InnermostFileScope->getParent();
+            UDirs.visitScopeChain(Initial, InnermostFileScope);
+
+            UDirs.done();
+
+            VisitedUsingDirectives = true;
+          }
 
           if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
             R.resolveKind();
@@ -994,11 +1011,11 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
   //
   // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
   // don't build it for each lookup!
-
-  UnqualUsingDirectiveSet UDirs;
-  UDirs.visitScopeChain(Initial, S);
-  UDirs.done();
-
+  if (!VisitedUsingDirectives) {
+    UDirs.visitScopeChain(Initial, S);
+    UDirs.done();
+  }
+  
   // Lookup namespace scope, and global scope.
   // Unqualified name lookup in C++ requires looking into scopes
   // that aren't strictly lexical, and therefore we walk through the
diff --git a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
index 7da3087e7d..272ad8568c 100644
--- a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
+++ b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
@@ -47,3 +47,22 @@ class Other {
 void Other::foo(YFloat a, YFloat b) {
   YFloat c = a - b;
 }
+
+// <rdar://problem/13540899>
+namespace Other {
+  void other_foo();
+}
+
+namespace M2 {
+  using namespace Other;
+
+  namespace MInner {
+    class Bar { 
+      void bar();
+    };
+  }
+}
+
+void M2::MInner::Bar::bar() {
+  other_foo();
+}