Editor crashes on load when a main screen plugin contains a viewport

[robbertzzz]

Godot version

4.0.3 stable

System information

Windows 11

Issue description

When a main screen plugin contains a viewport, the editor crashes on load.

Steps to reproduce

(See attached repro project below)

1. Launch the project
2. In project settings, turn on the plugin
3. Close the project
4. Open the project
5. Observe that the editor crashes on load

Minimal reproduction project

main_screen_viewport.zip

I uploaded a project where the plugin is turned off so you can look at the project without having to open any script editor to remove the plugin from the enabled list.

[Sauermann]

Here is a stacktrace:

handle_crash: Program crashed with signal 11
Engine version: Godot Engine v4.1.dev.custom_build (ed63b9ea236addd0d9cb6e0c6a862bd8fdf4978e)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[1] /lib/x86_64-linux-gnu/libc.so.6(+0x38d60) [0x7f41ded41d60] (??:0)
[2] Node::get_viewport() const (/srv/docker/data/godot-compile/godot/./scene/main/node.h:630)
[3] Camera2D::_update_scroll() (/srv/docker/data/godot-compile/godot/scene/2d/camera_2d.cpp:44)
[4] Camera2D::_notification(int) (/srv/docker/data/godot-compile/godot/scene/2d/camera_2d.cpp:260)
[5] Camera2D::_notificationv(int, bool) (/srv/docker/data/godot-compile/godot/scene/2d/camera_2d.h:37)
[6] Object::notification(int, bool) (/srv/docker/data/godot-compile/godot/core/object/object.cpp:796)
[7] Node::_propagate_enter_tree() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:261)
[8] Node::_propagate_enter_tree() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:278)
[9] Node::_propagate_enter_tree() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:278)
[10] Node::_set_tree(SceneTree*) (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:2900)
[11] Node::_add_child_nocheck(Node*, StringName const&, Node::InternalMode) (??:?)
[12] Node::add_child(Node*, bool, Node::InternalMode) (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:1385)
[13] void call_with_variant_args_helper<__UnexistingClass, Node*, bool, Node::InternalMode, 0ul, 1ul, 2ul>(__UnexistingClass*, void (__UnexistingClass::*)(Node*, bool, Node::InternalMode), Variant const**, Callable::CallError&, IndexSequence<0ul, 1ul, 2ul>) (/srv/docker/data/godot-compile/godot/./core/variant/binder_common.h:308)
[14] void call_with_variant_args_dv<__UnexistingClass, Node*, bool, Node::InternalMode>(__UnexistingClass*, void (__UnexistingClass::*)(Node*, bool, Node::InternalMode), Variant const**, int, Callable::CallError&, Vector<Variant> const&) (/srv/docker/data/godot-compile/godot/./core/variant/binder_common.h:451)
[15] MethodBindT<Node*, bool, Node::InternalMode>::call(Object*, Variant const**, int, Callable::CallError&) const (/srv/docker/data/godot-compile/godot/./core/object/method_bind.h:331)
[16] GDScriptFunction::call(GDScriptInstance*, Variant const**, int, Callable::CallError&, GDScriptFunction::CallState*) (/srv/docker/data/godot-compile/godot/modules/gdscript/gdscript_vm.cpp:1754)
[17] GDScriptInstance::callp(StringName const&, Variant const**, int, Callable::CallError&) (/srv/docker/data/godot-compile/godot/modules/gdscript/gdscript.cpp:1787)
[18] bool Node::_gdvirtual__enter_tree_call<false>() (/srv/docker/data/godot-compile/godot/./scene/main/node.h:320)
[19] Node::_propagate_enter_tree() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:263)
[20] Node::_set_tree(SceneTree*) (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:2900)
[21] Node::_add_child_nocheck(Node*, StringName const&, Node::InternalMode) (??:?)
[22] Node::add_child(Node*, bool, Node::InternalMode) (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:1385)
[23] EditorNode::add_editor_plugin(EditorPlugin*, bool) (/srv/docker/data/godot-compile/godot/editor/editor_node.cpp:3206)
[24] EditorNode::set_addon_plugin_enabled(String const&, bool, bool) (/srv/docker/data/godot-compile/godot/editor/editor_node.cpp:3372)
[25] EditorNode::_notification(int) (/srv/docker/data/godot-compile/godot/editor/editor_node.cpp:660)
[26] EditorNode::_notificationv(int, bool) (/srv/docker/data/godot-compile/godot/editor/editor_node.h:118)
[27] Object::notification(int, bool) (/srv/docker/data/godot-compile/godot/core/object/object.cpp:796)
[28] Node::_propagate_ready() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:235)
[29] Node::_propagate_ready() (/srv/docker/data/godot-compile/godot/scene/main/node.cpp:225)
[30] Node::_set_tree(SceneTree*) (??:?)
[31] SceneTree::initialize() (/srv/docker/data/godot-compile/godot/scene/main/scene_tree.cpp:448)
[32] OS_LinuxBSD::run() (/srv/docker/data/godot-compile/godot/platform/linuxbsd/os_linuxbsd.cpp:900)
[33] /srv/docker/data/godot-compile/godot/bin/godot-master(main+0x20f) [0x284bc5f] (/srv/docker/data/godot-compile/godot/platform/linuxbsd/godot_linuxbsd.cpp:73)
[34] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xea) [0x7f41ded2cd0a] (??:0)
[35] /srv/docker/data/godot-compile/godot/bin/godot-master(_start+0x2a) [0x284b98a] (??:?)
-- END OF BACKTRACE --