commit edbe69232a5b
Author: Martin Stransky <stransky@redhat.com>
Date:   Tue May 12 09:20:25 2020 +0000

    Bug 1636072 [Wayland] Don't crash when GetWlBuffer() fails, r=jhorak
    
    Differential Revision: https://phabricator.services.mozilla.com/D74663
---
 widget/gtk/WindowSurfaceWayland.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git widget/gtk/WindowSurfaceWayland.cpp widget/gtk/WindowSurfaceWayland.cpp
index 372158c9f0f33..56f5d3d530853 100644
--- widget/gtk/WindowSurfaceWayland.cpp
+++ widget/gtk/WindowSurfaceWayland.cpp
@@ -390,10 +390,13 @@ void WindowBackBuffer::Attach(wl_surface* aSurface) {
        (void*)GetWlBuffer(),
        GetWlBuffer() ? wl_proxy_get_id((struct wl_proxy*)GetWlBuffer()) : -1));
 
-  wl_surface_attach(aSurface, GetWlBuffer(), 0, 0);
-  wl_surface_commit(aSurface);
-  wl_display_flush(WaylandDisplayGetWLDisplay());
-  SetAttached();
+  wl_buffer* buffer = GetWlBuffer();
+  if (buffer) {
+    wl_surface_attach(aSurface, buffer, 0, 0);
+    wl_surface_commit(aSurface);
+    wl_display_flush(WaylandDisplayGetWLDisplay());
+    SetAttached();
+  }
 }
 
 void WindowBackBufferShm::Detach(wl_buffer* aBuffer) {