Wayland: Fix window hiding

Corrects the protocol violation when creating an xdg_surface from a
wl_surface that already has a buffer due to EGL buffer swaps.

This commit is based on PR #1731 by @ghost, but adapted and altered:
 - The XDG surface and role are now only created when a window is shown
   to prevent application lists from showing command-line applications
   with off-screen-only windows
 - The special case of Wayland+EGL buffer swap is now in the EGL code
   to mirror how X11 is handled
 - Adaption to run-time platform selection and separate credits file

Fixes #1492
Closes #1731

(cherry picked from commit 094aa6d3c7)

CONTRIBUTORS.md

@@ -58,6 +58,7 @@ video tutorials.
  - TheExileFox
  - Felipe Ferreira
  - Michael Fogleman
+ - Jason Francis
  - Gerald Franz
  - Mário Freitas
  - GeO4d

README.md

@@ -126,6 +126,7 @@ information on what to include when reporting a bug.
  - [Wayland] Bugfix: Key repeat could lead to a race condition (#1710)
  - [Wayland] Bugfix: Activating a window would emit two input focus events
  - [Wayland] Bugfix: Disable key repeat mechanism when window loses input focus
+ - [Wayland] Bugfix: Window hiding and showing did not work (#1492,#1731)
 
 
 ## Contact

src/egl_context.c

@@ -230,6 +230,12 @@ static void swapBuffersEGL(_GLFWwindow* window)
         return;
     }
 
+#if defined(_GLFW_WAYLAND)
+    // NOTE: Swapping buffers on a hidden window on Wayland makes it visible
+    if (!window->wl.visible)
+        return;
+#endif
+
     eglSwapBuffers(_glfw.egl.display, window->context.egl.surface);
 }
 

src/wl_window.c

@@ -950,29 +950,6 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
     if (wndconfig->title)
         window->wl.title = _glfw_strdup(wndconfig->title);
 
-    if (wndconfig->visible)
-    {
-        if (_glfw.wl.wmBase)
-        {
-            if (!createXdgSurface(window))
-                return GLFW_FALSE;
-        }
-        else
-        {
-            if (!createShellSurface(window))
-                return GLFW_FALSE;
-        }
-
-        window->wl.visible = GLFW_TRUE;
-    }
-    else
-    {
-        window->wl.xdg.surface = NULL;
-        window->wl.xdg.toplevel = NULL;
-        window->wl.shellSurface = NULL;
-        window->wl.visible = GLFW_FALSE;
-    }
-
     window->wl.currentCursor = NULL;
 
     window->wl.monitors = calloc(1, sizeof(_GLFWmonitor*));
@@ -1196,29 +1173,28 @@ void _glfwPlatformShowWindow(_GLFWwindow* window)
 {
     if (!window->wl.visible)
     {
+        // NOTE: The XDG/shell surface is created here so command-line applications
+        //       with off-screen windows do not appear in for example the Unity dock
         if (_glfw.wl.wmBase)
+        {
+            if (!window->wl.xdg.toplevel)
                 createXdgSurface(window);
+        }
         else if (!window->wl.shellSurface)
             createShellSurface(window);
+
         window->wl.visible = GLFW_TRUE;
     }
 }
 
 void _glfwPlatformHideWindow(_GLFWwindow* window)
 {
-    if (window->wl.xdg.toplevel)
+    if (window->wl.visible)
     {
-        xdg_toplevel_destroy(window->wl.xdg.toplevel);
-        xdg_surface_destroy(window->wl.xdg.surface);
-        window->wl.xdg.toplevel = NULL;
-        window->wl.xdg.surface = NULL;
-    }
-    else if (window->wl.shellSurface)
-    {
-        wl_shell_surface_destroy(window->wl.shellSurface);
-        window->wl.shellSurface = NULL;
-    }
         window->wl.visible = GLFW_FALSE;
+        wl_surface_attach(window->wl.surface, NULL, 0, 0);
+        wl_surface_commit(window->wl.surface);
+    }
 }
 
 void _glfwPlatformRequestWindowAttention(_GLFWwindow* window)