C# Adding more than one delegate to the same signal makes disconnect behave irratically

[Zoomulator]

Godot version

v4.0.3.stable.mono.official [5222a99]

System information

Windows 10

Issue description

Disconnecting a delegate (Action) from a signal who has been connected to more than once will sometimes (non-deterministically) cause a "nonexistent signal" error:

E 0:00:00:0911   Godot.NativeInterop.NativeFuncs.generated.cs:332 @ void Godot.NativeInterop.NativeFuncs.godotsharp_method_bind_ptrcall(IntPtr , IntPtr , System.Void** , System.Void* ): Disconnecting nonexistent signal 'tree_exiting', callable: Delegate::Invoke.
  <C++ Error>    Condition "!s->slot_map.has(*p_callable.get_base_comparator())" is true.
  <C++ Source>   core/object/object.cpp:1331 @ _disconnect()
  <Stack Trace>  Godot.NativeInterop.NativeFuncs.generated.cs:332 @ void Godot.NativeInterop.NativeFuncs.godotsharp_method_bind_ptrcall(IntPtr , IntPtr , System.Void** , System.Void* )
                 NativeCalls.cs:3541 @ void Godot.NativeCalls.godot_icall_2_412(IntPtr , IntPtr , Godot.NativeInterop.godot_string_name , Godot.Callable& )
                 GodotObject.cs:784 @ void Godot.GodotObject.Disconnect(Godot.StringName , Godot.Callable )
                 Node.cs:1646 @ void Godot.Node.remove_TreeExiting(System.Action )
                 Main.cs:20 @ void Main.TestOperator()
                 Main.cs:8 @ void Main._Ready()
                 Node.cs:1813 @ Boolean Godot.Node.InvokeGodotClassMethod(Godot.NativeInterop.godot_string_name& , Godot.NativeInterop.NativeVariantPtrArgs , Godot.NativeInterop.godot_variant& )
                 Main_ScriptMethods.generated.cs:45 @ Boolean Main.InvokeGodotClassMethod(Godot.NativeInterop.godot_string_name& , Godot.NativeInterop.NativeVariantPtrArgs , Godot.NativeInterop.godot_variant& )
                 CSharpInstanceBridge.cs:24 @ Godot.NativeInterop.godot_bool Godot.Bridge.CSharpInstanceBridge.Call(IntPtr , Godot.NativeInterop.godot_string_name* , Godot.NativeInterop.godot_variant** , Int32 , Godot.NativeInterop.godot_variant_call_error* , Godot.NativeInterop.godot_variant* )

Steps to reproduce

In a C# script for a Node, create two delegates, connect both to the same signal and then disconnect them.
This will sometimes give the error.

var c0 = () => GD.Print("c0");
var c1 = () => GD.Print("c1");

TreeExiting += c0;
TreeExiting += c1;
TreeExiting -= c0; // Sometimes ERROR
TreeExiting -= c1;

Minimal reproduction project

SignalDelegateDisconnect.zip

The scripts repeats 20 times to assure that the error is encountered. If there is no error, try it a few more times.

[Zoomulator]

Addendum: Actually it seems that it's the same for methods used as handlers as well, not just delegates.

[RedworkDE]

Confirmed on 4.0.3, no longer an issue on master (v4.1.dev.mono.custom_build 5dc093b)

(Almost certainly the MRP for the last point of #76708 (comment))

[Zoomulator]

I built the latest master and can confirm that it's fixed by #77199

You guys work so fast I second guess causality itself. Thanks!

[Zoomulator]

I cherry-picked some commits to get it working on my local build based on 4.0.3. Maybe possible to include these in the next maintenance release?

git cherry-pick -m 1 e0e93ce094d19d132f34aa5c92e892524a8125c9
git cherry-pick 1a4eccf7e74027c6204eed2fc06fe4309cdd8a2b
git cherry-pick 1cfc382fe89ba9df3d9edc2de07fbc28e594193a

from these pull requests
#72421
#76728
#77199