From fa0ea5c41f53119c68748a0e8570ef120b7fa703 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@elmindreda.org>
Date: Sun, 3 Dec 2023 16:06:31 +0100
Subject: [PATCH] Fix potential violation of invariant

The shared function for reading back context attributes,
_glfwRefreshContextAttribs, did not check whether the newly created
context had been successfully made current.  This violated the invariant
that the context TLS slot always points to a valid window and that its
context is current whenever _glfw.platform.getProcAddress is called.

Related to #2327
---
 src/context.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/context.c b/src/context.c
index 33b399c9..f8610e1e 100644
--- a/src/context.c
+++ b/src/context.c
@@ -363,6 +363,8 @@ GLFWbool _glfwRefreshContextAttribs(_GLFWwindow* window,
 
     previous = _glfwPlatformGetTls(&_glfw.contextSlot);
     glfwMakeContextCurrent((GLFWwindow*) window);
+    if (_glfwPlatformGetTls(&_glfw.contextSlot) != window)
+        return GLFW_FALSE;
 
     window->context.GetIntegerv = (PFNGLGETINTEGERVPROC)
         window->context.getProcAddress("glGetIntegerv");