From c644f2f4a410b34608cb4060bcbc2bf22dfd5ad7 Mon Sep 17 00:00:00 2001
From: Daniel Paoliello <danpao@microsoft.com>
Date: Tue, 30 Apr 2024 12:45:34 -0700
Subject: [PATCH] Fix crash when using a default argument from a base template

---
 sources/libClangSharp/ClangSharp.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sources/libClangSharp/ClangSharp.cpp b/sources/libClangSharp/ClangSharp.cpp
index 02c76f2d..ca3e2b4c 100644
--- a/sources/libClangSharp/ClangSharp.cpp
+++ b/sources/libClangSharp/ClangSharp.cpp
@@ -993,6 +993,9 @@ CXCursor clangsharp_Cursor_getDefaultArg(CXCursor C) {
         }
 
         if (const ParmVarDecl* PVD = dyn_cast<ParmVarDecl>(D)) {
+            if (PVD->hasUninstantiatedDefaultArg()) {
+                return MakeCXCursor(PVD->getUninstantiatedDefaultArg(), PVD, getCursorTU(C));
+            }
             return MakeCXCursor(PVD->getDefaultArg(), PVD, getCursorTU(C));
         }
     }