Wayland: Fix missing flush in glfwHideWindow

README.md

@@ -156,6 +156,7 @@ information on what to include when reporting a bug.
  - [Wayland] Bugfix: `glfwSwapBuffers` would halt with nonzero swap interval when window
    was suspended (#1350,#2582,#2640,#2719,#2723,#2800,#2827)
  - [Wayland] Bugfix: `glfwPostEmptyEvent` would leak a callback proxy (#2836)
+ - [Wayland] Bugfix: `glfwHideWindow` did not always send its request immediately
  - [X11] Bugfix: Running without a WM could trigger an assert (#2593,#2601,#2631)
  - [X11] Bugfix: Occasional crash when an idle display awakes (#2766) 
  - [X11] Bugfix: Prevent BadWindow when creating small windows with a content scale

src/wl_window.c

@@ -2726,6 +2726,8 @@ void _glfwHideWindowWayland(_GLFWwindow* window)
 
         wl_surface_attach(window->wl.surface, NULL, 0, 0);
         wl_surface_commit(window->wl.surface);
+
+        flushDisplay();
     }
 }