ClosePopupsOverWindow(): amend to remove _ChildWindow test.

Said test seems unnecessary and incorrect as we test hierarchy now. See test "nav_ctrl_tab_popups" in ImGuiTestSuite.

docs/CHANGELOG.txt

@@ -59,11 +59,13 @@ Other changes:
 - Nav, Menus: Fixed click on a BeginMenu() followed by right-arrow from making the child menu
   reopen and flicker (using ImGuiPopupFlags_NoReopen).
 - Nav: ImGuiWindowFlags_NoNavInputs is tested during scoring so NavFlattened windows can use it.
-- OpenPopup(): Added ImGuiPopupFlags_NoReopen flag to specifically not close and reopen a popup
+- Popups: OpenPopup(): added ImGuiPopupFlags_NoReopen flag to specifically not close and reopen
-  when it is already open. (#1497, #1533)
+  a popup when it is already open. (#1497, #1533)
   (Note that this differs from specific handling we already have in place for the case of calling
   OpenPopup() repeatedly every frame: we already didn't reopen in that specific situation, otherwise
   the effect would be very disastrous in term of confusion, as reopening would steal focus).
+- Popups: Slight change to popup closing logic (e.g. after focusing another window) which skipped
+  over popups that are also child windows.
 - Debug Tools: Metrics: Fixed debug break in SetShortcutRouting() not handling ImGuiMod_Shortcut redirect.
 - Debug Tools: Debug Log: Added "Input Routing" logging.
 - Debug Tools: Added "nop" to IM_DEBUG_BREAK macro on GCC to work around GDB bug (#7266) [@Peter0x44]

imgui.cpp

@@ -10819,14 +10819,15 @@ void ImGui::ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to
             if (!popup.Window)
                 continue;
             IM_ASSERT((popup.Window->Flags & ImGuiWindowFlags_Popup) != 0);
-            if (popup.Window->Flags & ImGuiWindowFlags_ChildWindow)
-                continue;
 
             // Trim the stack unless the popup is a direct parent of the reference window (the reference window is often the NavWindow)
-            // - With this stack of window, clicking/focusing Popup1 will close Popup2 and Popup3:
+            // - Clicking/Focusing Window2 won't close Popup1:
-            //     Window -> Popup1 -> Popup2 -> Popup3
+            //     Window -> Popup1 -> Window2(Ref)
+            // - Clicking/focusing Popup1 will close Popup2 and Popup3:
+            //     Window -> Popup1(Ref) -> Popup2 -> Popup3
             // - Each popups may contain child windows, which is why we compare ->RootWindow!
             //     Window -> Popup1 -> Popup1_Child -> Popup2 -> Popup2_Child
+            // We step through every popup from bottom to top to validate their position relative to reference window.
             bool ref_window_is_descendent_of_popup = false;
             for (int n = popup_count_to_keep; n < g.OpenPopupStack.Size; n++)
                 if (ImGuiWindow* popup_window = g.OpenPopupStack[n].Window)