Index: lib/Parse/ParseTemplate.cpp
===================================================================
--- lib/Parse/ParseTemplate.cpp
+++ lib/Parse/ParseTemplate.cpp
@@ -1255,15 +1255,23 @@
           new ParseScope(this, Scope::TemplateParamScope));
       Actions.ActOnReenterTemplateScope(getCurScope(), MD);
       ++CurTemplateDepthTracker;
-    } else if (CXXRecordDecl *MD = dyn_cast_or_null<CXXRecordDecl>(*II)) {
-      bool IsClassTemplate = MD->getDescribedClassTemplate() != 0;
+    } else if (CXXRecordDecl *RD = dyn_cast_or_null<CXXRecordDecl>(*II)) {
+      ClassTemplateDecl *CTD = RD->getDescribedClassTemplate();
+
+      if (!CTD) {
+        if (CXXRecordDecl *Parent = dyn_cast<CXXRecordDecl>(RD->getParent()))
+          CTD = Parent->getDescribedClassTemplate();
+      }
+
+      bool IsClassTemplate = CTD != 0;
       TemplateParamScopeStack.push_back(
           new ParseScope(this, Scope::TemplateParamScope, 
-                        /*ManageScope*/IsClassTemplate));
-      Actions.ActOnReenterTemplateScope(getCurScope(),
-                                        MD->getDescribedClassTemplate());
-      if (IsClassTemplate) 
+                        /*EnteredScope*/IsClassTemplate));
+
+      if (IsClassTemplate) {
+        Actions.ActOnReenterTemplateScope(getCurScope(), CTD);
         ++CurTemplateDepthTracker;
+      }
     }
     TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
     Actions.PushDeclContext(Actions.getCurScope(), *II);
Index: test/Parser/DelayedTemplateParsing.cpp
===================================================================
--- test/Parser/DelayedTemplateParsing.cpp
+++ test/Parser/DelayedTemplateParsing.cpp
@@ -123,3 +123,31 @@
 
 template <typename T>
 auto invalidTrailingRetType() -> Bogus {} // expected-error {{unknown type name 'Bogus'}}
+
+namespace PR19613 {
+
+struct HeapTypeConfig {
+  static void from_bitset();
+};
+
+template <class Config>
+struct TypeImpl  {
+  struct BitsetType;
+
+  static void Any() {
+    BitsetType::New();
+  }
+};
+
+template<class Config>
+struct TypeImpl<Config>::BitsetType {
+  static void New() {
+    Config::from_bitset();
+  }
+};
+
+static void f() {
+  TypeImpl<HeapTypeConfig>::Any();
+}
+
+}