From f9980b5715fc403383f8e99d5da8bb91538c996d Mon Sep 17 00:00:00 2001
From: Sergei Zimmerman <145775305+xokdvium@users.noreply.github.com>
Date: Tue, 26 Nov 2024 00:13:54 +0300
Subject: [PATCH] fix(libutil/config): declare virtual dtor for AbstractConfig

This prevents any potential cases of deletion through base pointer and its
non-virtual dtor, which might leak memory. Also gets rid of the warning:

/nix/store/fg7ass3a5m5pgl26qzfdniicbwbgzccy-gcc-13.2.0/include/c++/13.2.0/bits/stl_construct.h:88:2: warning: destructor called on non-final 'nix::flake::Settings' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor]
   88 |         __location->~_Tp();
....
../src/libflake-c/nix_api_flake.cc:10:30: note: in instantiation of function template specialization 'nix::make_ref<nix::flake::Settings>' requested here
   10 |         auto settings = nix::make_ref<nix::flake::Settings>();
---
 src/libutil/config.hh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/libutil/config.hh b/src/libutil/config.hh
index c0c59ac68..e98e09bf7 100644
--- a/src/libutil/config.hh
+++ b/src/libutil/config.hh
@@ -115,6 +115,8 @@ public:
      * Re-applies all previously attempted changes to unknown settings
      */
     void reapplyUnknownSettings();
+
+    virtual ~AbstractConfig() = default;
 };
 
 /**