From 1a92f92762ccff81e6e27030fcce57797e057e1e Mon Sep 17 00:00:00 2001
From: Jason Francis <jason@cycles.network>
Date: Sun, 12 Jul 2020 20:47:50 -0400
Subject: [PATCH] Wayland: Fix window hiding

Corrects the protocol violation with attaching an xdg_surface to a
wl_surface that already has a buffer.

Fixes  #1492
---
 README.md         |  2 ++
 src/context.c     |  2 +-
 src/egl_context.c |  2 +-
 src/wl_window.c   | 25 ++++++++++++++++---------
 4 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index e6440d519..da809dd7b 100644
--- a/README.md
+++ b/README.md
@@ -119,6 +119,7 @@ information on what to include when reporting a bug.
 
 ## Changelog
 
+ - [Wayland] Bugfix: Window hiding not working (#1492)
  - Added `GLFW_RESIZE_NWSE_CURSOR`, `GLFW_RESIZE_NESW_CURSOR`,
    `GLFW_RESIZE_ALL_CURSOR` and `GLFW_NOT_ALLOWED_CURSOR` cursor shapes (#427)
  - Added `GLFW_RESIZE_EW_CURSOR` alias for `GLFW_HRESIZE_CURSOR` (#427)
@@ -271,6 +272,7 @@ skills.
  - Siavash Eliasi
  - Felipe Ferreira
  - Michael Fogleman
+ - Jason Francis
  - Gerald Franz
  - Mário Freitas
  - GeO4d
diff --git a/src/context.c b/src/context.c
index 48311e5fd..6ea366ce0 100644
--- a/src/context.c
+++ b/src/context.c
@@ -566,7 +566,7 @@ GLFWbool _glfwRefreshContextAttribs(_GLFWwindow* window,
 
     // Clearing the front buffer to black to avoid garbage pixels left over from
     // previous uses of our bit of VRAM
-    {
+    if (_glfwPlatformWindowVisible(window)) {
         PFNGLCLEARPROC glClear = (PFNGLCLEARPROC)
             window->context.getProcAddress("glClear");
         glClear(GL_COLOR_BUFFER_BIT);
diff --git a/src/egl_context.c b/src/egl_context.c
index 533ed8e72..8eba0382e 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -221,7 +221,7 @@ static void makeContextCurrentEGL(_GLFWwindow* window)
     _glfwPlatformSetTls(&_glfw.contextSlot, window);
 }
 
-static void swapBuffersEGL(_GLFWwindow* window)
+void swapBuffersEGL(_GLFWwindow* window)
 {
     if (window != _glfwPlatformGetTls(&_glfw.contextSlot))
     {
diff --git a/src/wl_window.c b/src/wl_window.c
index d1dad0659..cc0bb2223 100644
--- a/src/wl_window.c
+++ b/src/wl_window.c
@@ -777,6 +777,14 @@ static void handleEvents(int timeout)
     }
 }
 
+void swapBuffersEGL(_GLFWwindow* window);
+
+static void swapBuffersWL(_GLFWwindow* window)
+{
+    if (window->wl.visible)
+        swapBuffersEGL(window);
+}
+
 //////////////////////////////////////////////////////////////////////////
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////
@@ -800,6 +808,7 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
                 return GLFW_FALSE;
             if (!_glfwCreateContextEGL(window, ctxconfig, fbconfig))
                 return GLFW_FALSE;
+            window->context.swapBuffers = swapBuffersWL;
         }
         else if (ctxconfig->source == GLFW_OSMESA_CONTEXT_API)
         {
@@ -813,10 +822,11 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
     if (wndconfig->title)
         window->wl.title = _glfw_strdup(wndconfig->title);
 
+    if (!createXdgSurface(window))
+        return GLFW_FALSE;
+
     if (wndconfig->visible)
     {
-        if (!createXdgSurface(window))
-            return GLFW_FALSE;
 
         window->wl.visible = GLFW_TRUE;
     }
@@ -1019,21 +1029,18 @@ void _glfwPlatformShowWindow(_GLFWwindow* window)
 {
     if (!window->wl.visible)
     {
-        createXdgSurface(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;
+        wl_surface_attach(window->wl.surface, NULL, 0, 0);
+        wl_surface_commit(window->wl.surface);
+        window->wl.visible = GLFW_FALSE;
     }
-    window->wl.visible = GLFW_FALSE;
 }
 
 void _glfwPlatformRequestWindowAttention(_GLFWwindow* window)