Crash when adding a dock to DOCK_SLOT_RIGHT_BL

[blackears]

Tested versions

Godot v4.6.1.stable

I think this was working in 4.5

System information

Godot v4.6.1.stable - Windows 11 (build 26200) - Multi-window, 2 monitors - OpenGL 3 (Compatibility) - NVIDIA T1000 8GB (NVIDIA; 32.0.15.8142) - Intel(R) Core(TM) i7-14700 (28 threads) - 47.69 GiB memory

Issue description

I'm getting a crash in a plugin I developed which was working fine in Godot 4.0 through 4.5, but has an issue in 4.6 and the master 4.7 dev branch.

I was able to track it down to :

margin_container.cpp, line 44
		Size2 s = c->get_combined_minimum_size();

For some reason the method wrapper is passing a null pointer as a Variant to the parameter list which causes the crash.

This is caused indirectly by adding a dock control to the editor, which in turn tries to resize a MarginContainer, which leads to the above call.

Steps to reproduce

Load the attached project. Open the main.tscn panel in the editor. In the Scene panel, click back and forth between the CoolBeans nodes and the background to select/deselect them a few times. After a couple of clicks back and forth, the project will crash.

Minimal reproduction project (MRP)

minimum_size_crash.zip

[TokisanGames]

The dock was completely rewritten and is not fully backwards compatible. The issue may have been triggered by this PR: #106503
Though the issue is a crash, the solution may be using the new API.

EditorDock is now derived from MarginContainer.

[kleonc]

That's a regression from #106503, remove_control_from_docks(tool_properties_dock) ends up freeing tool_properties_dock, see the fix linked above.

[blackears]

Okay, I rewrote it to follow the new guidelines for Godot 4.6. There is still an issue, though. The dock only shows up the first time. After you remove it and try to re-add it, it is not displayed.

minimum_size_crash.zip

[kleonc]

Okay, I rewrote it to follow the new guidelines for Godot 4.6. There is still an issue, though. The dock only shows up the first time. After you remove it and try to re-add it, it is not displayed.

minimum_size_crash.zip

Can reproduce in:

• v4.6.1.stable.official [14d1969]
• v4.6.2.rc1.official [257ac35]

Can't reproduce in:

• v4.7.dev1.official [bf95b62]
• v4.7.dev2.official [778cf54]

So whatever the issue was, seems already fixed. But the fix would need to be cherrypicked into 4.6, I don't know which PR fixed it. Any idea @KoBeWi ? If not, would need bisecting.

[KoBeWi]

I didn't test, but maybe #113199

[TrueJole]

I bisected, but I am not sure if I perhaps not made a mistake: #108391

1932a5c07fb018d7bf361c9811a010833d44300a is the first bad commit
commit 1932a5c07fb018d7bf361c9811a010833d44300a
Merge: 8ff0683def 0d16f7893b
Author: Thaddeus Crews <repiteo@outlook.com>
Date:   Fri Nov 14 14:23:10 2025 -0600

    Merge pull request #108391 from KoBeWi/archeoexpressology
    
    Add expression history to evaluator

 editor/debugger/editor_expression_evaluator.cpp | 44 +++++++++++++++++++++++++++++++++++++++++++-
 editor/debugger/editor_expression_evaluator.h   |  4 ++++
 2 files changed, 47 insertions(+), 1 deletion(-)

[kleonc]

I didn't test, but maybe #113199

I've bisected, it's fixed by #115482. Will extract the fix and open a PR against 4.6 branch.