From e1060cde30ae73d0ce2f3aedcd1c2e6ace6486a6 Mon Sep 17 00:00:00 2001
From: Grimmauld <Grimmauld@grimmauld.de>
Date: Sat, 1 Aug 2026 13:00:34 +0200
Subject: [PATCH] coin3d: unvendor expat

closes #544607

Using the ancient vendored `expat` 2.2.10 from 2020-10-03 is a security
nightmare. It also recently started exploding due to symbol collisions
with the significantly newer expat used in python3, crashing FreeCAD.

Co-authored-by: Patrick Lawrence <patrick.lawrence@gmail.com>
---
 pkgs/by-name/co/coin3d/package.nix | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pkgs/by-name/co/coin3d/package.nix b/pkgs/by-name/co/coin3d/package.nix
index c5faea3690d1..e6631df9b49d 100644
--- a/pkgs/by-name/co/coin3d/package.nix
+++ b/pkgs/by-name/co/coin3d/package.nix
@@ -7,6 +7,7 @@
   libGL,
   libGLU,
   libx11,
+  expat,
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -26,9 +27,14 @@ stdenv.mkDerivation (finalAttrs: {
     boost
     libGL
     libGLU
+    expat
   ]
   ++ lib.optional stdenv.hostPlatform.isLinux libx11;
 
+  cmakeFlags = [
+    (lib.cmakeBool "USE_EXTERNAL_EXPAT" true)
+  ];
+
   meta = {
     homepage = "https://github.com/coin3d/coin";
     description = "High-level, retained-mode toolkit for effective 3D graphics development";