From 0ac7e427a17764ccdbe22add65a20427ac113294 Mon Sep 17 00:00:00 2001
From: Matthias Melcher <github@matthiasm.com>
Date: Fri, 31 Oct 2025 20:37:24 +0100
Subject: Avoid crash in Fl_Gl_Window::make_current() (#1287)

---
 src/Fl_Gl_Window.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Fl_Gl_Window.cxx b/src/Fl_Gl_Window.cxx
index b56bd30f9..d82340de4 100644
--- a/src/Fl_Gl_Window.cxx
+++ b/src/Fl_Gl_Window.cxx
@@ -118,6 +118,10 @@ int Fl_Gl_Window::mode(int m, const int *a) {
 void Fl_Gl_Window::make_current() {
 //  puts("Fl_Gl_Window::make_current()");
 //  printf("make_current: context_=%p\n", context_);
+  // The following line prevents potential crashes when make_current() is
+  // called before show(). Applications should call show() before
+  // make_current() for proper initialization.
+  if (!shown()) return;
   pGlWindowDriver->make_current_before();
   if (!context_) {
     mode_ &= ~NON_LOCAL_CONTEXT;
-- 
cgit v1.2.3