Frame hover glitch when moving on overlapping item border, with SetNextItemAllowOverlap about imgui HOT 2 OPEN

I have a pushed a test for the current behavior (which isn't necessarily correct)
ocornut/imgui_test_engine@33b9786
In particular I think the third section showcase the difference between IsItemHovered() and hover state as reported via ButtonBehavior()->ItemHoverable().

So if we introduce changes we can aim to validate them against current test and fix the test accordingly.

from imgui.

Here's the C++ repro:

// #7515
{
    ImGui::SeparatorText("#7515");
    ImVec2 pos = ImGui::GetCursorPos();

    ImGui::SetNextItemAllowOverlap();
    ImGui::Button("button3", { 50.0f, 50.0f });
    bool h1 = ImGui::IsItemHovered();
    pos.y += 25;
    ImGui::SetCursorPos(pos);
    ImGui::Button("Button4", { 50.0f, 50.0f });// # button or dummy, irrelevant
    //ImGui::Dummy({ 50.0f, 50.0f });
    bool h2 = ImGui::IsItemHovered();
    if (h1 || h2)
        printf("[%05d] %s%s\n", ImGui::GetFrameCount(), h1 ? "hover top button" : "", h2 ? "hover bottom button" : "");
}

when moving down (bad):
220, hover top button
221, hover top button, hover bottom button
222, hover bottom button

I consider this an issue, let me investigate.

when moving up (bad):
252, hover bottom button
253
254, hover top button

This is the same as #7514 and I don't consider this an issue.

from imgui.