From d75c7debad4509ece98792074e64b8a650a27bdb Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Fri, 14 Feb 2020 21:24:03 +0000
Subject: Vendor import of llvm-project branch release/10.x
 llvmorg-10.0.0-rc2-0-g90c78073f73.

---
 clang/lib/Sema/SemaTemplate.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'clang/lib/Sema/SemaTemplate.cpp')

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index f961244da072..ad4ea2d2593d 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -2047,12 +2047,14 @@ private:
       if (const auto *TC = TTP->getTypeConstraint()) {
         TemplateArgumentListInfo TransformedArgs;
         const auto *ArgsAsWritten = TC->getTemplateArgsAsWritten();
-        if (SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
+        if (!ArgsAsWritten ||
+            SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
                           ArgsAsWritten->NumTemplateArgs, TransformedArgs,
                           Args))
           SemaRef.AttachTypeConstraint(
               TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
-              TC->getNamedConcept(), &TransformedArgs, NewTTP,
+              TC->getNamedConcept(), ArgsAsWritten ? &TransformedArgs : nullptr,
+              NewTTP,
               NewTTP->isParameterPack()
                  ? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
                      ->getEllipsisLoc()
-- 
cgit v1.2.3