Window is destroyed multiple times

[psychon]

Running cd druid-shell && cargo run --example invalidate --features=x11 with the following patch and then closing the window results in the following output

diff --git a/druid-shell/src/platform/x11/window.rs b/druid-shell/src/platform/x11/window.rs
index f2def4a..c0b958e 100644
--- a/druid-shell/src/platform/x11/window.rs
+++ b/druid-shell/src/platform/x11/window.rs
@@ -510,6 +510,7 @@ impl Window {
 
     /// Start the destruction of the window.
     pub fn destroy(&self) {
+        println!("Destroy");
         log_x11!(self.app.connection().destroy_window(self.id));
     }
 

INFO  [druid_shell::platform::x11::application] X server supports Present version 1.0
INFO  [druid_shell::platform::x11::application] X server supports XFIXES version 5.0
Destroy
Destroy
ERROR [druid_shell::platform::x11::application] Error handling event: X11 error Window(ValueError { error_code: 3, sequence: 270, bad_value: 33554433, minor_opcode: 0, major_opcode: 4 })

The X11 error obviously occurs because druid-shell tries to destroy the window twice. The second destroy fails since the window is already gone. So, I guess something needs to keep track of the "destroyed" state and prevent.... basically any new interaction with the window. All functions need to do the equivalent of if destroyed { return; }.

Relevant backtraces:

Breakpoint 1, druid_shell::platform::x11::window::Window::destroy (self=0x555555746da0)
    at druid-shell/src/platform/x11/window.rs:513
513	        println!("Destroy");
(gdb) bt
#0  druid_shell::platform::x11::window::Window::destroy (self=0x555555746da0) at druid-shell/src/platform/x11/window.rs:513
#1  0x00005555555d331a in druid_shell::platform::x11::window::Window::close (self=0x555555746da0)
    at druid-shell/src/platform/x11/window.rs:642
#2  0x00005555555d5c8f in druid_shell::platform::x11::window::Window::handle_client_message
    (self=0x555555746da0, client_message=0x7fffffffda84) at druid-shell/src/platform/x11/window.rs:888
#3  0x0000555555588855 in druid_shell::platform::x11::application::Application::handle_event
    (self=0x7fffffffe190, ev=0x7fffffffda80) at druid-shell/src/platform/x11/application.rs:313
#4  0x000055555558a29a in druid_shell::platform::x11::application::Application::run_inner (self=...)
    at druid-shell/src/platform/x11/application.rs:409
#5  0x000055555558b380 in druid_shell::platform::x11::application::Application::run (self=..., _handler=...)
    at druid-shell/src/platform/x11/application.rs:450
#6  0x00005555555806f8 in druid_shell::application::Application::run (self=..., handler=...)
    at druid-shell/src/application.rs:153
#7  0x000055555557a647 in invalidate::main () at druid-shell/examples/invalidate.rs:102

Breakpoint 1, druid_shell::platform::x11::window::Window::destroy (self=0x555555746da0)
    at druid-shell/src/platform/x11/window.rs:513
513	        println!("Destroy");
(gdb) bt
#0  druid_shell::platform::x11::window::Window::destroy (self=0x555555746da0) at druid-shell/src/platform/x11/window.rs:513
#1  0x000055555558b8c6 in druid_shell::platform::x11::application::Application::quit (self=0x7fffffffc990)
    at druid-shell/src/platform/x11/application.rs:466
#2  0x000055555558081a in druid_shell::application::Application::quit (self=0x7fffffffc990)
    at druid-shell/src/application.rs:169
#3  0x000055555557a1cb in <invalidate::InvalidateTest as druid_shell::window::WinHandler>::destroy (self=0x555555739250)
    at druid-shell/examples/invalidate.rs:78
#4  0x00005555555d5da6 in druid_shell::platform::x11::window::Window::handle_destroy_notify
    (self=0x555555746da0, _destroy_notify=0x7fffffffda84) at druid-shell/src/platform/x11/window.rs:899
#5  0x0000555555588b01 in druid_shell::platform::x11::application::Application::handle_event
    (self=0x7fffffffe190, ev=0x7fffffffda80) at druid-shell/src/platform/x11/application.rs:326
#6  0x000055555558a29a in druid_shell::platform::x11::application::Application::run_inner (self=...)
    at druid-shell/src/platform/x11/application.rs:409
#7  0x000055555558b380 in druid_shell::platform::x11::application::Application::run (self=..., _handler=...)
    at druid-shell/src/platform/x11/application.rs:450
#8  0x00005555555806f8 in druid_shell::application::Application::run (self=..., handler=...)
    at druid-shell/src/application.rs:153
#9  0x000055555557a647 in invalidate::main () at druid-shell/examples/invalidate.rs:102