Crash when opening a converted FogMaterial

[Chaosus]

Godot version

75baf16

System information

Windows 10

Issue description

Crash with the following stack trace:

CrashHandlerException: Program crashed
Engine version: Godot Engine v4.0.dev.custom_build (75baf16bab073fb52fb0ec33f08517cfb3febaa1)
Dumping the backtrace. Please include this when reporting the bug on https://github.com/godotengine/godot/issues
[0] ShaderLanguage::constant_value_to_variant (C:\Git\godot\servers\rendering\shader_language.cpp:3471)
[1] RendererSceneRenderRD::FogShaderData::get_default_parameter (C:\Git\godot\servers\rendering\renderer_rd\renderer_scene_render_rd.cpp:3617)
[2] RendererStorageRD::shader_get_param_default (C:\Git\godot\servers\rendering\renderer_rd\renderer_storage_rd.cpp:1509)
[3] RenderingServerDefault::shader_get_param_default (C:\Git\godot\servers\rendering\rendering_server_default.h:234)
[4] ShaderMaterial::property_can_revert (C:\Git\godot\scene\resources\material.cpp:177)
[5] call_with_variant_args_retc_dv<EditorSettings,bool,String const &> (C:\Git\godot\core\variant\binder_common.h:454)
[6] MethodBindTRC<EditorSettings,bool,String const &>::call (C:\Git\godot\core\object\method_bind.h:443)
[7] Object::call (C:\Git\godot\core\object\object.cpp:832)
[8] Object::call (C:\Git\godot\core\object\object.cpp:774)
[9] EditorPropertyRevert::get_property_revert_value (C:\Git\godot\editor\editor_inspector.cpp:532)
[10] EditorProperty::update_reload_status (C:\Git\godot\editor\editor_inspector.cpp:588)
[11] EditorInspector::update_tree (C:\Git\godot\editor\editor_inspector.cpp:2891)
[12] EditorInspector::edit (C:\Git\godot\editor\editor_inspector.cpp:2961)
[13] EditorPropertyResource::update_property (C:\Git\godot\editor\editor_properties.cpp:3079)
[14] EditorPropertyResource::_resource_selected (C:\Git\godot\editor\editor_properties.cpp:2829)
[15] call_with_variant_args<ScriptEditor,Ref<Resource> const &> (C:\Git\godot\core\variant\binder_common.h:337)
[16] Callable::call (C:\Git\godot\core\variant\callable.cpp:51)
[17] Object::emit_signal (C:\Git\godot\core\object\object.cpp:1100)
[18] Object::emit_signal (C:\Git\godot\core\object\object.cpp:1155)
[19] EditorResourcePicker::_resource_selected (C:\Git\godot\editor\editor_resource_picker.cpp:109)
[20] Callable::call (C:\Git\godot\core\variant\callable.cpp:51)
[21] Object::emit_signal (C:\Git\godot\core\object\object.cpp:1100)
[22] Object::emit_signal (C:\Git\godot\core\object\object.cpp:1155)
[23] BaseButton::_pressed (C:\Git\godot\scene\gui\base_button.cpp:126)
[24] BaseButton::on_action_event (C:\Git\godot\scene\gui\base_button.cpp:168)
[25] BaseButton::gui_input (C:\Git\godot\scene\gui\base_button.cpp:67)
[26] Control::_call_gui_input (C:\Git\godot\scene\gui\control.cpp:823)
[27] Viewport::_gui_call_input (C:\Git\godot\scene\main\viewport.cpp:1266)
[28] Viewport::_gui_input_event (C:\Git\godot\scene\main\viewport.cpp:1566)
[29] Viewport::push_input (C:\Git\godot\scene\main\viewport.cpp:2681)
[30] Window::_window_input (C:\Git\godot\scene\main\window.cpp:920)
[31] call_with_variant_args<VisualScriptEditor,Ref<InputEvent> const &> (C:\Git\godot\core\variant\binder_common.h:337)
[32] Callable::call (C:\Git\godot\core\variant\callable.cpp:51)
[33] DisplayServerWindows::_dispatch_input_event (C:\Git\godot\platform\windows\display_server_windows.cpp:1850)
[34] Input::_parse_input_event_impl (C:\Git\godot\core\input\input.cpp:621)
[35] Input::flush_buffered_events (C:\Git\godot\core\input\input.cpp:841)
[36] DisplayServerWindows::process_events (C:\Git\godot\platform\windows\display_server_windows.cpp:1575)
[37] OS_Windows::run (C:\Git\godot\platform\windows\os_windows.cpp:641)
[38] widechar_main (C:\Git\godot\platform\windows\godot_windows.cpp:163)
[39] _main (C:\Git\godot\platform\windows\godot_windows.cpp:187)
[40] main (C:\Git\godot\platform\windows\godot_windows.cpp:199)
[41] __scrt_common_main_seh (d:\agent\_work\4\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288)
[42] BaseThreadInitThunk
-- END OF BACKTRACE --

Steps to reproduce

Create a FogMaterial, convert to ShaderMaterial - attempting to click on it in the inspector to open, result in a crash.

Minimal reproduction project

Too trivial to reproduce.

[mhilbrunner]

Like #54371, this may be a regression from #53353, cc @clayjohn