Port window hit-test hole so PassthruCentralNode doesn't capture the mouse

build/ImGui.luau

@@ -7387,7 +7387,10 @@ local function FindHoveredWindowEx(pos, find_first_and_in_any_viewport)
         end
 
         if window.HitTestHoleSize.x ~= 0 then
-            -- TODO: hit test hole
+            local hx, hy = window.Pos.x + window.HitTestHoleOffset.x, window.Pos.y + window.HitTestHoleOffset.y
+            if pos.x >= hx and pos.y >= hy and pos.x < hx + window.HitTestHoleSize.x and pos.y < hy + window.HitTestHoleSize.y then
+                break -- continue
+            end
         end
 
         if find_first_and_in_any_viewport then

imgui/imgui.lua

@@ -7376,7 +7376,10 @@ local function FindHoveredWindowEx(pos, find_first_and_in_any_viewport)
         end
 
         if window.HitTestHoleSize.x ~= 0 then
-            -- TODO: hit test hole
+            local hx, hy = window.Pos.x + window.HitTestHoleOffset.x, window.Pos.y + window.HitTestHoleOffset.y
+            if pos.x >= hx and pos.y >= hy and pos.x < hx + window.HitTestHoleSize.x and pos.y < hy + window.HitTestHoleSize.y then
+                break -- continue
+            end
         end
 
         if find_first_and_in_any_viewport then

tools/test/scripts/t_passthru.luau

@@ -0,0 +1,23 @@
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local RunService = game:GetService("RunService")
+local G = require(ReplicatedStorage:WaitForChild("ImGui"))
+local ImGui, ImVec2 = G.ImGui, G.ImVec2
+ImGui.CreateContext()
+local io = ImGui.GetIO()
+io.ConfigFlags = bit32.bor(io.ConfigFlags, G.ImGuiConfigFlags.DockingEnable)
+G.ImGui_ImplRoblox.Init()
+local frame = 0
+RunService.Stepped:Connect(function()
+    frame += 1
+    G.ImGui_ImplRoblox.NewFrame()
+    if frame == 5 then io:AddMousePosEvent(io.DisplaySize.x * 0.5, io.DisplaySize.y * 0.5) end
+    if frame == 10 then io:AddMousePosEvent(60, 60) end
+    ImGui.NewFrame()
+    ImGui.DockSpaceOverViewport(0, nil, G.ImGuiDockNodeFlags.PassthruCentralNode)
+    ImGui.SetNextWindowPos(ImVec2(20, 20)); ImGui.SetNextWindowSize(ImVec2(200, 200))
+    ImGui.Begin("W"); ImGui.Text("hi"); ImGui.End()
+    ImGui.Render()
+    if frame == 8 then assert(not io.WantCaptureMouse, "central node must not capture") end
+    if frame == 13 then assert(io.WantCaptureMouse, "window must capture"); print("PASSTHRU OK") end
+    G.ImGui_ImplRoblox.RenderDrawData(ImGui.GetDrawData())
+end)