imgui: Assertion failed: g.IO.KeyMods with GLFW backend

Dear ImGui 1.77 (17700)
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sizeof(size_t): 8, sizeof(ImDrawIdx): 4, sizeof(ImDrawVert): 20
define: __cplusplus=199711
define: _WIN32
define: _WIN64
define: _MSC_VER=1926
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io.BackendPlatformName: imgui_impl_glfw
io.BackendRendererName: imgui_impl_opengl3
io.ConfigFlags: 0x00000000
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigWindowsMemoryCompactTimer = 60.0f
io.BackendFlags: 0x0000000E
 HasMouseCursors
 HasSetMousePos
 RendererHasVtxOffset
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io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,64
io.DisplaySize: 1280.00,720.00
io.DisplayFramebufferScale: 1.00,1.00
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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

I’m running into something that I can’t seem to get to the bottom of, and I’m hoping you can help. I’m using a framework on top of ImGui, which implements key bindings and actions. I’m running into a situation where when I execute an action from a key binding, and then I launch a native file dialog, I’m running into an assert in ImGui when the dialog returns control back to ImGui.

I get the following assert:

Assertion failed: g.IO.KeyMods == expected_key_mod_flags && "Mismatching io.KeyCtrl/io.KeyShift/io.KeyAlt/io.KeySuper vs io.KeyMods", file ..\imgui\imgui.cpp, line 6765

My code is structured like this:

inline void host::draw(const ImVec2& size) {
    ImGui_ImplOpenGL3_NewFrame();
    ImGui_ImplGlfw_NewFrame();
    ImGui::NewFrame();

    _app->draw(ImGui::GetIO().DisplaySize);
    _app->respond();

    ImGui::Render();
    glViewport(0, 0, size.x, size.y);
    glClearColor(_bg.x, _bg.y, _bg.z, _bg.w);
    glClear(GL_COLOR_BUFFER_BIT);
    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
    glfwSwapBuffers(_window);
}

void workspace_app::respond() {
    auto io = ImGui::GetIO();
    if(!io.WantCaptureKeyboard) {
        for(const auto& action : _actions) {
            if(action->triggered(io)) {
                action->execute();
                return;
            }
        }
    }
}

bool action::triggered(const ImGuiIO& io) const {
    return _key_binding->triggered(io);
}

bool key_binding::triggered(const ImGuiIO& io) const {
    return (io.KeyCtrl == ctrl && io.KeyAlt == alt && io.KeyShift == shift && ImGui::IsKeyPressed(key));
}

The workspace_app::respond is the concrete overload responding to the _app->respond() line in host::draw above.

When I invoke this same code path through clicking on a user interface element, the code path works perfectly. It only triggers this assert when I use the keyboard shortcut (CTRL-S) in my case, to invoke the code path. If I change my keyboard shortcut to just S instead of CTRL-S, it also works perfectly. It only seems to hit this assert when modifier keys are involved.

Any insight would be very appreciated.