Clicking on void loses keyboard-focus so application can use TAB back

imgui.cpp

@@ -2153,13 +2153,21 @@ void ImGui::Render()
             g.CurrentWindow->Visible = false;
         ImGui::End();
 
-        // Select window for move/focus when we're done with all our widgets (we use the root window ID here)
+        if (g.ActiveId == 0 && g.HoveredId == 0 && g.IO.MouseClicked[0])
-        if (g.ActiveId == 0 && g.HoveredId == 0 && g.HoveredRootWindow != NULL && g.IO.MouseClicked[0])
+        {
+            if (g.HoveredRootWindow != NULL)
             {
+                // Select window for move/focus when we're done with all our widgets (we use the root window ID here)
                 IM_ASSERT(g.MovedWindow == NULL);
                 g.MovedWindow = g.HoveredWindow;
                 SetActiveId(g.HoveredRootWindow->MoveID);
             }
+            else if (g.FocusedWindow != NULL)
+            {
+                // Clicking on void disable focus
+                FocusWindow(NULL);
+            }
+        }
 
         // Sort the window list so that all child windows are after their parent
         // We cannot do that on FocusWindow() because childs may not exist yet