Correct importing of the type of a TemplateArgument

It's not clear how this would be tested - I imagine we should have an
ASTImporter test that RAVs the new AST and checks that all the elements
in it are from this ASTContext and not the foreign one... but I know
little about the ASTImporter and how/where that testing might be done.

(post-commit review feedback from Richard Smith on r219900)

llvm-svn: 220411

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 02864a5d4d9..07b2a73ee85 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -2092,10 +2092,11 @@ ASTNodeImporter::ImportTemplateArgument(const TemplateArgument &From) {
   }
 
   case TemplateArgument::Declaration: {
-    ValueDecl *FromD = From.getAsDecl();
-    if (ValueDecl *To = cast_or_null<ValueDecl>(Importer.Import(FromD)))
-      return TemplateArgument(To, From.getParamTypeForDecl());
-    return TemplateArgument();
+    ValueDecl *To = cast_or_null<ValueDecl>(Importer.Import(From.getAsDecl()));
+    QualType ToType = Importer.Import(From.getParamTypeForDecl());
+    if (!To || ToType.isNull())
+      return TemplateArgument();
+    return TemplateArgument(To, ToType);
   }
 
   case TemplateArgument::NullPtr: {