call_group() does not always call all nodes in the group

[db0]

3.2.3 stable official

OS/device including version:

Windows 10 x64
Issue description:

I have a part in my code, where I want to execute a method on all nodes in a group. The method which includes the call_group() is initiated by a signal from one of the nodes in that group.

In some special circumstance, which I'm not exactly certain about, the call_group() will call the method on all nodes except the node which sent the original signal.

However, I can make the call_group() work with the following two workarounds:

• Change call_group() to call_group_flags(SceneTree.GROUP_CALL_UNIQUE, ...)
• Use a for loop like so for node in cfc.get_tree().get_nodes_in_group("group_name"):

Both of the above will correctly execute on all nodes, including the one sending the signal. All other flags for call_group_flags() also fail to execute on the signaling node.

This also works when I trigger the signal in a slightly different set of behaviours. Please see me reproduction info.
Steps to reproduce:

So, this is quite tricky to replicate in a minimal project as it seems to work normally, but I seem to have crafted a situation where I can make it appear only if I trigger the signal with a specific setup.

As I cannot craft a minimal product, I have instead created a branch in my repo which I have prepared so that this bug is immediately reproducible: https://github.com/db0/godot-card-game-framework/tree/GROUP_CALL_UNIQUE-bug

To reproduce:

1. Clone my git repo and checkout the GROUP_CALL_UNIQUE-bug branch
2. Run main scene with F5
3. A hand of 5 blue cards will appear.
4. Drag a blue card from the hand anywhere on the board. It will be placed in the PlacementGridDemo and 6 "bio" tokens appear correctly.
5. Drag a blue card from the hand specifically inside the "PlacementGridDemo" area. You will see only 2 "bio" tokens appear. However the code is setup so that 6 should appear. One via each call_group_flags() flag, one via call_group() and one via the for loop.

I have replicated this with simple prints as well, so it's not an issue with the "token adding" code. The execute_scripts() function is really not called at all on the trigger card. This way is just easier to see visually.

The 6 group calls are defined in res://src/core/CFControl.gd Line 234
You can see that they all originate in the same spot and are called in the same manner. But for some reason, 4 out of 6 fail to execute on

Apologies for the complexity of this report, but I couldn't find a better way to report it.

[omicron321]

1. Clone and run main scene.

2. A hand of 5 blue cards will appear.

so main scene is... res://src/custom/CGFMain.tscn

1. there are no such thing as cloning a scene, but many options... duplicate, instance, new inherited scene... etc.
2. i didn't get that 5 blue cards appearing for options i have tried
3. n/a

[db0]

there are no such thing as cloning a scene, but many options... duplicate, instance, new inherited scene... etc.

I meant, git clone the repository, switch to the branch I mentioned and just run the whole project with F5 :) CGFMAin.tcsn should be already set as the main project scene.

i didn't get that 5 blue cards appearing for options i have tried

Did you switch to the GROUP_CALL_UNIQUE-bug branch? This is what I've prepared to replicate the issue

[omicron321]

i could reproduce described issue with your steps
i couldn't build a MWE from scratch from empty scene
so i guess one of step to isolate bug could be to prune everything in that branch that isn't required to reproduce that bug

[db0]

That's going to be quite tricky as there's a lot of interconnected pieces before one gets to that point. I think this bug appears precisely because of some weird interaction in the whole process.

I do not know how Godot development works, but an alternative would be if one could attach a breakpoint in the C++ code at the point where it's calling the groups,it might point out why the signal card is not being called.

[Calinou]

@db0 Can you (or anyone else) still reproduce this bug in Godot 3.3.3 or any later release?

If yes, can you reproduce this after switching to call_group_flags() with the GROUP_CALL_REALTIME flag passed? This disables deferred calling to use immediate calling instead. If this resolves the issue, then #51591 should make things better in this regard 🙂

[db0]

Tried it just now (same branch as in my report). Issue persists using the GROUP_CALL_REALTIME flag. Only GROUP_CALL_UNIQUE works correctly.

[kleonc]

To reproduce:

1. Clone my git repo and checkout the `GROUP_CALL_UNIQUE-bug` branch

2. Run main scene with F5

3. A hand of 5 blue cards will appear.

4. Drag  a blue card from the hand anywhere on the board. It will be placed in the PlacementGridDemo and 6 "bio" tokens appear correctly.

5. Drag a blue card from the hand  specifically inside the "PlacementGridDemo" area. You will see only 2 "bio" tokens appear. However the code is setup so that 6 should appear. One via each `call_group_flags()` flag, one via `call_group()` and one via the for loop.

Can confirm (only 2 "bio" tokens appear). I've opened a PR with the fix, with it applied 6 "bio" tokens appear as expected. Until then a reliable workaround is this same as for #67819.