Ensure that we transform types into the current instantiation even if

they're only instantiation-dependent.

Author: zygoloid

clang/lib/Sema/SemaDecl.cpp

@@ -5491,7 +5491,7 @@ static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
     // Grab the type from the parser.
     TypeSourceInfo *TSI = nullptr;
     QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
-    if (T.isNull() || !T->isDependentType()) break;
+    if (T.isNull() || !T->isInstantiationDependentType()) break;
 
     // Make sure there's a type source info.  This isn't really much
     // of a waste; most dependent types should have type source info

clang/lib/Sema/SemaTemplate.cpp

@@ -10730,7 +10730,7 @@ namespace {
     /// For the purposes of type reconstruction, a type has already been
     /// transformed if it is NULL or if it is not dependent.
     bool AlreadyTransformed(QualType T) {
-      return T.isNull() || !T->isDependentType();
+      return T.isNull() || !T->isInstantiationDependentType();
     }
 
     /// Returns the location of the entity whose type is being
@@ -10783,7 +10783,7 @@ namespace {
 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
                                                         SourceLocation Loc,
                                                         DeclarationName Name) {
-  if (!T || !T->getType()->isDependentType())
+  if (!T || !T->getType()->isInstantiationDependentType())
     return T;
 
   CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);

clang/test/SemaTemplate/class-template-decl.cpp

@@ -167,3 +167,17 @@ namespace abstract_dependent_class {
   };
   template<typename T> A<T> *A<T>::clone() { return new A<T>; } // expected-error {{abstract class type 'A<T>'}}
 }
+
+namespace qualified_out_of_line {
+  struct rbnode {};
+  template<typename T, typename U> struct pair {};
+  template<typename K, typename V> struct rbtree {
+    using base = rbnode;
+    pair<base, base> f();
+  };
+  template<typename K, typename V>
+  pair<typename rbtree<K, V>::base, typename rbtree<K, V>::base>
+  rbtree<K, V>::f() {
+    return {};
+  }
+}