3 files changed, 23 insertions, 2 deletions
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index d26566684b..aa1e062b31 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -720,7 +720,9 @@ def err_temp_copy_deleted : Error<
   "object|copying member subobject|copying array element|allocating object|"
   "copying temporary|initializing base subobject|initializing vector element}0 "
   "of type %1 invokes deleted constructor">;
-  
+def err_temp_copy_incomplete : Error<
+  "copying a temporary object of incomplete type %0">;
+
 // C++0x decltype
 def err_cannot_determine_declared_type_of_overloaded_function : Error<
     "cannot determine the %select{type|declared type}0 of an overloaded "
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index d552b16399..ea430bbd3e 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3232,7 +3232,11 @@ static Sema::OwningExprResult CopyObject(Sema &S,
     Loc = CurInitExpr->getLocStart();
     break;
   }
-    
+
+  // Make sure that the type we are copying is complete.   
+  if (S.RequireCompleteType(Loc, T, S.PDiag(diag::err_temp_copy_incomplete)))
+    return move(CurInit);
+
   // Perform overload resolution using the class's copy constructors.
   DeclarationName ConstructorName
     = S.Context.DeclarationNames.getCXXConstructorName(
diff --git a/test/SemaTemplate/instantiate-complete.cpp b/test/SemaTemplate/instantiate-complete.cpp
index bc91112497..d854c9e6aa 100644
--- a/test/SemaTemplate/instantiate-complete.cpp
+++ b/test/SemaTemplate/instantiate-complete.cpp
@@ -84,3 +84,18 @@ namespace PR6376 {
 
   template struct Y<int, float>;
 }
+
+namespace TemporaryObjectCopy {
+  // Make sure we instantiate classes when we create a temporary copy.
+  template<typename T>
+  struct X {
+    X(T); 
+  };
+
+  template<typename T>
+  void f(T t) {
+    const X<int> &x = X<int>(t);
+  }
+
+  template void f(int);
+}