From ad8dd440d2b395167c591bb7b5eb659dbb57ad07 Mon Sep 17 00:00:00 2001
From: ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
Date: Fri, 7 Apr 2023 14:47:03 +0200
Subject: Wayland: fix for issue #712 (hopefully)

---
 src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

(limited to 'src/drivers/Wayland')

diff --git a/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx b/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx
index a7b3610d8..1e0f87cf9 100644
--- a/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx
+++ b/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.cxx
@@ -84,10 +84,12 @@ static void surface_frame_done(void *data, struct wl_callback *cb, uint32_t time
   struct wld_window *window = (struct wld_window *)data;
 //fprintf(stderr,"surface_frame_done:  destroy cb=%p draw_buffer_needs_commit=%d\n", cb, window->buffer->draw_buffer_needs_commit);
   wl_callback_destroy(cb);
-  window->buffer->cb = NULL;
-  if (window->buffer->draw_buffer_needs_commit) {
-//fprintf(stderr,"surface_frame_done: new cb=%p \n", window->buffer->cb);
-    Fl_Wayland_Graphics_Driver::buffer_commit(window);
+  if (window->buffer) { // fix for issue #712
+    window->buffer->cb = NULL;
+    if (window->buffer->draw_buffer_needs_commit) {
+      //fprintf(stderr,"surface_frame_done: new cb=%p \n", window->buffer->cb);
+      Fl_Wayland_Graphics_Driver::buffer_commit(window);
+    }
   }
 }
 
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