From f72ef286737b5e3a00701fb1c941f6650619aa42 Mon Sep 17 00:00:00 2001
From: nicebyte <12521759+nicebyte@users.noreply.github.com>
Date: Wed, 27 Dec 2023 20:31:11 -0800
Subject: [PATCH] [glfw] Early-out of  GLFW WndProc hook if ImGui has already
 been torn down

If we happen to call  `glfwTerminate`  after destroying the ImGui context, the WndProc that ImGui installs still gets triggered, but there is no backend data at that time. This is a simple one-line fix that just early-outs if `bd` is NULL for whatever reason.
---
 backends/imgui_impl_glfw.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/backends/imgui_impl_glfw.cpp b/backends/imgui_impl_glfw.cpp
index 60723d2700ef..b88f270f172a 100644
--- a/backends/imgui_impl_glfw.cpp
+++ b/backends/imgui_impl_glfw.cpp
@@ -483,6 +483,7 @@ static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
 static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (!bd) { return DefWindowProc(hWnd, msg, wParam, lParam); }
     switch (msg)
     {
     case WM_MOUSEMOVE: case WM_NCMOUSEMOVE: