2 files changed, 28 insertions, 1 deletions
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 2f3309b0593..878243932c8 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3281,7 +3281,6 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
   for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
     TemplateArgLists.addOuterTemplateArguments(None);
 
-  Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
   EnterExpressionEvaluationContext ConstantEvaluated(SemaRef,
                                                      Sema::ConstantEvaluated);
   return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
diff --git a/clang/test/SemaTemplate/default-arguments.cpp b/clang/test/SemaTemplate/default-arguments.cpp
index 740a5a9d07b..d3e249db7ee 100644
--- a/clang/test/SemaTemplate/default-arguments.cpp
+++ b/clang/test/SemaTemplate/default-arguments.cpp
@@ -179,3 +179,31 @@ struct C {
   C(T t = ); // expected-error {{expected expression}}
 };
 C<int> obj;
+
+namespace PR26134 {
+// Make sure when substituting default template arguments we do it in the current context.
+template<class T, bool Val = T::value>
+struct X {};
+
+template<bool B> struct Y {
+  void f() { X<Y> xy; }
+  static const bool value = B;
+};
+
+namespace ns1 {
+template<class T0>
+struct X {
+  template<bool B = T0::value> struct XInner { static const bool value = B; };
+};
+template<bool B> struct S { static const bool value = B; };
+#if __cplusplus > 199711L
+template<bool B> struct Y {
+  static constexpr bool f() { return typename X<S<B>>::template XInner<>{}.value; }
+  static_assert(f() == B, "");
+};
+Y<true> y;
+Y<false> y2;
+#endif
+
+} // end ns1
+} // end ns PR26134