Dragging any Resource not recognized by the editor over the viewport crashes Godot

[coppolaemilio]

Tested versions

v4.3.dev4.official [df78c06]

System information

Godot v4.3.dev4 - macOS 14.2.1 - Vulkan (Forward+) - integrated Apple M1 Pro - Apple M1 Pro (10 Threads)

Issue description

When dragging a theme over the viewport, the editor crashes.

Kapture.2024-03-02.at.18.35.44.mp4

I get this from the crash dialog, not sure if it helps:

-------------------------------------
Translated Report (Full Report Below)
-------------------------------------

Process:               Godot [94104]
Path:                  /Applications/Godot.app/Contents/MacOS/Godot
Identifier:            org.godotengine.godot
Version:               4.3 (4.3)
Code Type:             ARM-64 (Native)
Parent Process:        launchd [1]
User ID:               501

Date/Time:             2024-03-02 18:35:36.4833 +0100
OS Version:            macOS 14.2.1 (23C71)
Report Version:        12
Anonymous UUID:        33ED798A-8EC3-E728-0035-E4E197B21DF8

Sleep/Wake UUID:       14A2FDC0-AF33-4169-BAFF-3E500503288E

Time Awake Since Boot: 540000 seconds
Time Since Wake:       12305 seconds

System Integrity Protection: enabled

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGABRT)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000000000188
Exception Codes:       0x0000000000000001, 0x0000000000000188

Termination Reason:    Namespace SIGNAL, Code 6 Abort trap: 6
Terminating Process:   Godot [94104]

VM Region Info: 0x188 is not in any region.  Bytes before following region: 105554726878840
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      MALLOC_NANO              600060000000-600080000000 [512.0M] rw-/rwx SM=PRV  

Application Specific Information:
abort() called

If I don't hover with the dragged resource over the viewport and play a game of moving only around the editor, it doesn't crashes. So I assume that there is something going wrong when trying to make a preview of the resource in the viewport? or something like that 🤷‍♂️

Kapture.2024-03-02.at.18.38.44.mp4

Steps to reproduce

Download the project, drag the res://UI/MainTheme.tres into the viewport.

Minimal reproduction project (MRP)

This is the current project I'm using on the videos. It is not a super minimal version of it, but it is small enough.

MRP.zip

[KoBeWi]

CrashHandlerException: Program crashed
Engine version: Godot Engine v4.3.dev.custom_build (9fc1d6eb3634007f4103cafbdfd5f2ab58753bfb)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[0] CowData<char32_t>::_ref (C:\godot_source\core\templates\cowdata.h:459)
[1] String::String (C:\godot_source\core\string\ustring.h:458)
[2] Node::get_scene_file_path (C:\godot_source\scene\main\node.cpp:2414)
[3] CanvasItemEditorViewport::can_drop_data (C:\godot_source\editor\plugins\canvas_item_editor_plugin.cpp:5942)
[4] Viewport::_gui_drop (C:\godot_source\scene\main\viewport.cpp:1748)
[5] Viewport::_gui_input_event (C:\godot_source\scene\main\viewport.cpp:2109)
[6] Viewport::push_input (C:\godot_source\scene\main\viewport.cpp:3375)
[7] Window::_window_input (C:\godot_source\scene\main\window.cpp:1611)
[8] call_with_variant_args_helper<Window,Ref<InputEvent> const &,0> (C:\godot_source\core\variant\binder_common.h:304)
[9] call_with_variant_args<Window,Ref<InputEvent> const &> (C:\godot_source\core\variant\binder_common.h:419)
[10] CallableCustomMethodPointer<Window,Ref<InputEvent> const &>::call (C:\godot_source\core\object\callable_method_pointer.h:99)
[11] Callable::callp (C:\godot_source\core\variant\callable.cpp:58)
[12] Callable::call<Ref<InputEvent> > (C:\godot_source\core\variant\variant.h:864)
[13] DisplayServerWindows::_dispatch_input_event (C:\godot_source\platform\windows\display_server_windows.cpp:3155)
[14] DisplayServerWindows::_dispatch_input_events (C:\godot_source\platform\windows\display_server_windows.cpp:3125)
[15] Input::_parse_input_event_impl (C:\godot_source\core\input\input.cpp:773)
[16] Input::flush_buffered_events (C:\godot_source\core\input\input.cpp:1044)
[17] DisplayServerWindows::process_events (C:\godot_source\platform\windows\display_server_windows.cpp:2674)
[18] OS_Windows::run (C:\godot_source\platform\windows\os_windows.cpp:1476)
[19] widechar_main (C:\godot_source\platform\windows\godot_windows.cpp:182)
[20] _main (C:\godot_source\platform\windows\godot_windows.cpp:204)
[21] main (C:\godot_source\platform\windows\godot_windows.cpp:218)
[22] WinMain (C:\godot_source\platform\windows\godot_windows.cpp:232)
[23] __scrt_common_main_seh (D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288)
[24] <couldn't map PC to fn name>
-- END OF BACKTRACE --

Happens with any Resource not recognized by the editor. Fixing it requires a simple null check.

[luevano]

I think it is actually related to #88829?

[3] CanvasItemEditorViewport::can_drop_data (C:\godot_source\editor\plugins\canvas_item_editor_plugin.cpp:5942) this section of the code points to a commit related to that PR, may I attempt a fix for this?

[luevano]

I have a fix ready but I'm not sure if I'm capturing all scenarios; @KoBeWi what other Resources did you test with?

How did you get that log?

[KoBeWi]

This bug happens for any resource that isn't Texture2D or PackedScene. You can get a log by crashing in a build with debug symbols (e.g. dev_build=yes in scons).