[wayland_xdg_egl] add initial commit for wl_surface after setting xdg_surface states

wayland_xdg_egl.c

@@ -405,9 +405,23 @@ int main(){
     
     /* [1] */
     xdg_toplevel_add_listener(ctx.xdg_toplevel, &xdg_toplevel_listener, NULL);
+    
+    /* (2) xdg_surface
+    ** " After creating a role-specific object and setting it up (e.g. by sending
+    **   the title, app ID, size constraints, parent, etc), the client must perform
+    **   an initial commit without any buffer attached. The compositor will reply
+    **   with initial wl_surface state such as wl_surface.preferred_buffer_scale
+    **   followed by an xdg_surface.configure event. The client must acknowledge
+    **   it and is then allowed to attach a buffer to map the surface. "
+    **
+    **~NOTE: The "without any buffer attached" here literally translates to
+    **  "before eglCreateWindowSurface" which does the actual buffer attachment
+    **  (at least based on my testing - citation needed)
+    */
+    wl_surface_commit(ctx.wl_surface);
   }
   
-  if (ctx.xdg_surface != 0){
+  if (ctx.xdg_toplevel != 0){
     /* (1) Appendix A: wl_compositor::create_region
     ** " create new region "
     */

x11_egl.c

@@ -239,7 +239,7 @@ int main(int argc, char **argv){
   */
   EGLBoolean swap_interval_success = 0;
   if (make_current_success2){
-    swap_interval_success = eglSwapInterval(ctx.egl_display, 1);
+    swap_interval_success = eglSwapInterval(egl_display, 1);
     if (!swap_interval_success){
       printf("eglSwapInterval failed\n");
     }