From 680b57564dc5f9d3dced8627889c0204d8441b55 Mon Sep 17 00:00:00 2001
From: Krystian Stasiowski <sdkrystian@gmail.com>
Date: Thu, 5 Feb 2026 10:01:56 -0500
Subject: [PATCH] [Clang][Sema] Fix crash when nested-name-specifier prefix
 points to non-dependent context

---
 clang/lib/Sema/SemaCXXScopeSpec.cpp         |  2 +-
 clang/test/SemaTemplate/dependent-names.cpp | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index 17ae7ca5627a9..e21f15bea576e 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -33,7 +33,7 @@ static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
     return nullptr;
   auto *RD = cast<CXXRecordDecl>(TagTy->getDecl())->getDefinitionOrSelf();
   if (isa<InjectedClassNameType>(TagTy) ||
-      RD->isCurrentInstantiation(CurContext))
+      (RD->isDependentContext() && RD->isCurrentInstantiation(CurContext)))
     return RD;
   return nullptr;
 }
diff --git a/clang/test/SemaTemplate/dependent-names.cpp b/clang/test/SemaTemplate/dependent-names.cpp
index d6bd670841c08..332c4a3342fd2 100644
--- a/clang/test/SemaTemplate/dependent-names.cpp
+++ b/clang/test/SemaTemplate/dependent-names.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -fms-extensions %s
 
 typedef double A;
 template<typename T> class B {
@@ -481,3 +482,17 @@ namespace TransformNestedName {
   template <typename T::template X<N<T>::State::kA>>
   inline void N<T>::F() {}
 } // namespace TransformNestedName
+
+namespace GH133610 {
+  struct a {
+    using e = int;
+  };
+
+#ifdef _MSC_EXTENSIONS
+  void current(const char * = __builtin_FUNCSIG());
+  template <class> void c() {
+    decltype(a(current()))::e;
+  }
+#endif
+}
+