BeginDragDropTarget makes tree node disappears

[IniKiwi]

Version/Branch of Dear ImGui:

Version dev, Branch: docking

Back-ends:

imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp

Compiler, OS:

Linux Debian 12

Full config/build information:

Dear ImGui 1.91.5 WIP (19141)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=201703
define: __linux__
define: __GNUC__=13
define: IMGUI_HAS_VIEWPORT
define: IMGUI_HAS_DOCK
--------------------------------
io.BackendPlatformName: imgui_impl_glfw
io.BackendRendererName: imgui_impl_opengl3
io.ConfigFlags: 0x00000081
 NavEnableKeyboard
 DockingEnable
io.ConfigViewportsNoDecoration
io.ConfigNavCaptureKeyboard
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigWindowsMoveFromTitleBarOnly
io.ConfigMemoryCompactTimer = 60.0
io.BackendFlags: 0x00001C0E
 HasMouseCursors
 HasSetMousePos
 PlatformHasViewports
 HasMouseHoveredViewport
 RendererHasVtxOffset
 RendererHasViewports
--------------------------------
io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,128
io.DisplaySize: 1280.00,720.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

Details:

I'm following this example https://github.com/ocornut/imgui/blob/368123ab06b2b573d585e52f84cd782c5c006697/imgui_demo.cpp#L2662C48-L2662C71. But when I'm adding a drag and drop target, treenodes disappears.

Screenshots/Video:

https://github.com/user-attachments/assets/cb85b607-c829-444f-ac66-b3c6d5f0369e

Minimal, Complete and Verifiable Example code:

int flags = ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick | ImGuiTreeNodeFlags_SpanTextWidth;
    if(m_SelectedObject == e) flags |= ImGuiTreeNodeFlags_Selected;
    std::set<Instance*> childs = e->GetChildrens();
    if(!(childs.size() > 0)) flags |= ImGuiTreeNodeFlags_Leaf;

    std::string label = fmt::format("{}{}", InstanceClassNameToIcon(e), e->GetName());

    bool skip;
    if(show){
        skip = ImGui::TreeNodeEx((void*)e, flags, label.c_str());
        if (ImGui::IsItemClicked() && !ImGui::IsItemToggledOpen()) m_SelectedObject = e;
        if(ImGui::BeginDragDropSource(ImGuiDragDropFlags_None)){
            ImGui::SetDragDropPayload("_INSTANCE", e, sizeof(void*));
            ImGui::Text(label.c_str());
            ImGui::EndDragDropSource();
        }

        /*if(ImGui::BeginDragDropTarget()){
            if(const ImGuiPayload* payload = ImGui::AcceptDragDropPayload("_INSTANCE")){
                IM_ASSERT(payload->DataSize == sizeof(void*));
                Instance* object = (Instance*)payload->Data;
                object->SetParent(e);
            }
            ImGui::EndDragDropTarget();
        }*/

        if (ImGui::BeginPopupContextItem()){
            m_SelectedObject = e;
            ImGui::MenuItem(ICON_CUT_RED" Cut", "Ctrl+X", &m_instanceContextMenuActions.Cut);
            ImGui::MenuItem(ICON_PAGE_COPY" Copy", "Ctrl+C", &m_instanceContextMenuActions.Copy);
            ImGui::MenuItem(ICON_BLANK" Paste Into", "Ctrl+Shift+V", &m_instanceContextMenuActions.PasteInto);
            ImGui::MenuItem(ICON_PAGE_COPY" Duplicate", "Ctrl+D", &m_instanceContextMenuActions.Duplicate);
            ImGui::MenuItem(ICON_DELETE" Delete", "Del", &m_instanceContextMenuActions.Delete);
            ImGui::MenuItem(ICON_PENCIL" Rename", "", &m_instanceContextMenuActions.Rename);
            ImGui::Separator();
            ImGui::MenuItem(ICON_SHAPE_GROUP" Group", "Ctrl+G", &m_instanceContextMenuActions.Group);
            ImGui::MenuItem(ICON_SHAPE_UNGROUP" Ungroup", "Ctrl+U", &m_instanceContextMenuActions.Ungroup);
            ImGui::Separator();
            ImGui::MenuItem(ICON_BRICK_ADD" Insert Part", "", &m_instanceContextMenuActions.InsertPart);
            ImGui::MenuItem(ICON_BRICK_ADD" Insert Object", "", &m_instanceContextMenuActions.InsertPart);
            ImGui::EndPopup();
        }
    }

    if(skip){
        for(Instance* child: childs){
            RenderExplorerElement(child);
        }
        if(show)ImGui::TreePop();
    }

[ocornut]

Hello, Your code is missing details, but it would be good if you can narrow this into a more minimal repro can I can paste anywhere.