[Lldb-commits] [lldb] Detect against invalid variant index for LibStdC++ std::variant data formatters (PR #69253)

[Greg Clayton via lldb-commits]

================
@@ -914,6 +914,11 @@ def get_variant_npos_value(index_byte_size):
     if index == npos_value:
         return " No Value"
 
+    # Invalid index can happen when the variant is not initialized yet.
+    template_arg_count = data_obj.GetType().GetNumberOfTemplateArguments()
+    if index >= template_arg_count:
+        return " <Invalid>"
+
     active_type = data_obj.GetType().GetTemplateArgumentType(index)
----------------
clayborg wrote:

If this is what was crashing, we should modify the GetTemplateArgumentType(<index>) to not crash with an inalid index as part of this fix.

https://github.com/llvm/llvm-project/pull/69253