[-fms-extensions] Don't crash on explicit class-scope specializations & default arguments

The code had a typo it was doing:
  Param->setUninstantiatedDefaultArg(Param->getUninstantiatedDefaultArg());

This is a no-op but may assert, we wanted to do:
  Param->setUninstantiatedDefaultArg(OldParam->getUninstantiatedDefaultArg());

This fixes PR28082.

llvm-svn: 272425

2 files changed, 10 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index 3db75c7ee79..3c5134268e8 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -381,7 +381,7 @@ void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
       assert (!OldParam->hasUnparsedDefaultArg());
       if (OldParam->hasUninstantiatedDefaultArg())
         Param->setUninstantiatedDefaultArg(
-                                      Param->getUninstantiatedDefaultArg());
+            OldParam->getUninstantiatedDefaultArg());
       else
         Param->setDefaultArg(OldParam->getInit());
     }
diff --git a/clang/test/SemaTemplate/ms-function-specialization-class-scope.cpp b/clang/test/SemaTemplate/ms-function-specialization-class-scope.cpp
index 5da00837cc0..3c7111d0583 100644
--- a/clang/test/SemaTemplate/ms-function-specialization-class-scope.cpp
+++ b/clang/test/SemaTemplate/ms-function-specialization-class-scope.cpp
@@ -75,3 +75,12 @@ namespace Duplicates {
   // here.
   template struct A<int>;
 }
+
+namespace PR28082 {
+struct S {
+  template <int>
+  int f(int = 0);
+  template <>
+  int f<0>(int); // expected-warning {{Microsoft extension}}
+};
+}