2 files changed, 31 insertions, 1 deletions
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index af60a56564c..ebd33db1602 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -10356,6 +10356,18 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
 
   LSI->CallOperator = NewCallOperator;
 
+  for (unsigned I = 0, NumParams = NewCallOperator->getNumParams();
+       I != NumParams; ++I) {
+    auto *P = NewCallOperator->getParamDecl(I);
+    if (P->hasUninstantiatedDefaultArg()) {
+      EnterExpressionEvaluationContext Eval(
+          getSema(), Sema::PotentiallyEvaluatedIfUsed, P);
+      ExprResult R = getDerived().TransformExpr(
+          E->getCallOperator()->getParamDecl(I)->getDefaultArg());
+      P->setDefaultArg(R.get());
+    }
+  }
+
   getDerived().transformAttrs(E->getCallOperator(), NewCallOperator);
   getDerived().transformedLocalDecl(E->getCallOperator(), NewCallOperator);
 
diff --git a/clang/test/SemaCXX/vartemplate-lambda.cpp b/clang/test/SemaCXX/vartemplate-lambda.cpp
index 9dab6da3d1e..5b91e232e3a 100644
--- a/clang/test/SemaCXX/vartemplate-lambda.cpp
+++ b/clang/test/SemaCXX/vartemplate-lambda.cpp
@@ -1,18 +1,36 @@
 // RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify %s
-// expected-no-diagnostics
 
 template <class> auto fn0 = [] {};
 template <typename> void foo0() { fn0<char>(); }
 
 template<typename T> auto fn1 = [](auto a) { return a + T(1); };
+template<typename T> auto v1 = [](int a = T(1)) { return a; }();
+
+struct S {
+  template<class T>
+  static constexpr T t = [](int f = T(7)){return f;}(); // expected-error{{constexpr variable 't<int>' must be initialized by a constant expression}} expected-error{{a lambda expression may not appear inside of a constant expression}} expected-note{{cannot be used in a constant expression}}
+};
 
 template <typename X>
 int foo2() {
   X a = 0x61;
   fn1<char>(a);
+  (void)v1<int>;
+  (void)S::t<int>; // expected-note{{in instantiation of static data member 'S::t<int>' requested here}}
   return 0;
 }
 
+template<class C>
+int foo3() {
+  C::m1(); // expected-error{{type 'long long' cannot be used prior to '::' because it has no members}}
+  return 1;
+}
+
+template<class C>
+auto v2 = [](int a = foo3<C>()){};  // expected-note{{in instantiation of function template specialization 'foo3<long long>' requested here}}
+
 int main() {
+  v2<long long>();  // This line causes foo3<long long> to be instantiated.
+  v2<long long>(2); // This line does not.
   foo2<int>();
 }