From cb0dafa7c028c958c59626d6d830d87af8da5627 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

This was adapted to 3.3-stable from
fa0ea5c41f53119c68748a0e8570ef120b7fa703 and
ddd92a4fa8dea2729ad2ea09172a8cfd541e53e7.
---
 CONTRIBUTORS.md | 1 +
 README.md       | 1 +
 src/context.c   | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index faa6431a..ee473382 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -202,6 +202,7 @@ video tutorials.
  - Matt Sealey
  - Steve Sexton
  - Arkady Shapkin
+ - Mingjie Shen
  - Ali Sherief
  - Yoshiki Shibukawa
  - Dmitri Shuralyov
diff --git a/README.md b/README.md
index 19e361c6..080ab1e2 100644
--- a/README.md
+++ b/README.md
@@ -124,6 +124,7 @@ information on what to include when reporting a bug.
 ## Changelog
 
  - Bugfix: `glfwGetKeyScancode` returned `0` on error when initialized instead of `-1`
+ - Bugfix: Failure to make a newly created context current could cause segfault (#2327)
  - [Win32] Fix pkg-config for dynamic library on Windows (#2386, #2420)
  - [Win32] Bugfix: `glfwWaitEventsTimeout` did not return for some sent messages (#2408)
  - [Wayland] Added improved fallback window decorations via libdecor (#1639,#1693)
diff --git a/src/context.c b/src/context.c
index 93c9a935..b81934bb 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");