wayland: Ensure that the xdg_surface is always configured after creation

The spec states that xdg_surface must have seen an initial configure event before attaching a buffer, however, this was only being done when initially showing the window, and not after show->hide->show cycle.

Always wait for the initial configure event when (re)creating an xdg_surface as part of the show window sequence.

Author: Kontrabant

src/video/wayland/SDL_waylandwindow.c

@@ -181,7 +181,7 @@ static void SetMinMaxDimensions(SDL_Window *window)
 
 #ifdef HAVE_LIBDECOR_H
     if (wind->shell_surface_type == WAYLAND_SHELL_SURFACE_TYPE_LIBDECOR) {
-        if (!wind->shell_surface.libdecor.initial_configure_seen || !wind->shell_surface.libdecor.frame) {
+        if (!wind->shell_surface.libdecor.frame) {
             return; // Can't do anything yet, wait for ShowWindow
         }
         /* No need to change these values if the window is non-resizable,
@@ -198,7 +198,7 @@ static void SetMinMaxDimensions(SDL_Window *window)
     } else
 #endif
         if (wind->shell_surface_type == WAYLAND_SHELL_SURFACE_TYPE_XDG_TOPLEVEL) {
-        if (wind->shell_surface.xdg.toplevel.xdg_toplevel == NULL) {
+        if (!wind->shell_surface.xdg.toplevel.xdg_toplevel) {
             return; // Can't do anything yet, wait for ShowWindow
         }
         xdg_toplevel_set_min_size(wind->shell_surface.xdg.toplevel.xdg_toplevel,
@@ -750,7 +750,9 @@ static void handle_configure_xdg_shell_surface(void *data, struct xdg_surface *x
         xdg_surface_ack_configure(xdg, serial);
     }
 
-    wind->shell_surface.xdg.initial_configure_seen = true;
+    if (wind->shell_surface_status == WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE) {
+        wind->shell_surface_status = WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_FRAME;
+    }
 }
 
 static const struct xdg_surface_listener shell_surface_listener_xdg = {
@@ -980,10 +982,6 @@ static void handle_configure_xdg_toplevel(void *data,
     wind->active = active;
     window->tiled = tiled;
     wind->resizing = resizing;
-
-    if (wind->shell_surface_status == WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE) {
-        wind->shell_surface_status = WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_FRAME;
-    }
 }
 
 static void handle_close_xdg_toplevel(void *data, struct xdg_toplevel *xdg_toplevel)
@@ -1132,9 +1130,7 @@ static void handle_configure_zxdg_decoration(void *data,
         WAYLAND_wl_display_roundtrip(internal->waylandData->display);
 
         Wayland_HideWindow(device, window);
-        SDL_zero(internal->shell_surface);
         internal->shell_surface_type = WAYLAND_SHELL_SURFACE_TYPE_LIBDECOR;
-
         Wayland_ShowWindow(device, window);
     }
 }
@@ -1417,11 +1413,8 @@ static void decoration_frame_configure(struct libdecor_frame *frame,
         libdecor_state_free(state);
     }
 
-    if (!wind->shell_surface.libdecor.initial_configure_seen) {
-        LibdecorGetMinContentSize(frame, &wind->system_limits.min_width, &wind->system_limits.min_height);
-        wind->shell_surface.libdecor.initial_configure_seen = true;
-    }
     if (wind->shell_surface_status == WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE) {
+        LibdecorGetMinContentSize(frame, &wind->system_limits.min_width, &wind->system_limits.min_height);
         wind->shell_surface_status = WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_FRAME;
     }
 
@@ -1830,12 +1823,10 @@ void Wayland_ShowWindow(SDL_VideoDevice *_this, SDL_Window *window)
         }
     }
 
-    /* The window was hidden, but the sync point hasn't yet been reached.
-     * Pump events to avoid a possible protocol violation.
-     */
-    if (data->show_hide_sync_required) {
+    // Always roundtrip to ensure there are no pending buffer attachments.
+    do {
         WAYLAND_wl_display_roundtrip(c->display);
-    }
+    } while (data->show_hide_sync_required);
 
     data->shell_surface_status = WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE;
 
@@ -1996,7 +1987,7 @@ void Wayland_ShowWindow(SDL_VideoDevice *_this, SDL_Window *window)
 #ifdef HAVE_LIBDECOR_H
     if (data->shell_surface_type == WAYLAND_SHELL_SURFACE_TYPE_LIBDECOR) {
         if (data->shell_surface.libdecor.frame) {
-            while (!data->shell_surface.libdecor.initial_configure_seen) {
+            while (data->shell_surface_status == WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE) {
                 WAYLAND_wl_display_flush(c->display);
                 WAYLAND_wl_display_dispatch(c->display);
             }
@@ -2010,7 +2001,7 @@ void Wayland_ShowWindow(SDL_VideoDevice *_this, SDL_Window *window)
          */
         wl_surface_commit(data->surface);
         if (data->shell_surface.xdg.surface) {
-            while (!data->shell_surface.xdg.initial_configure_seen) {
+            while (data->shell_surface_status == WAYLAND_SHELL_SURFACE_STATUS_WAITING_FOR_CONFIGURE) {
                 WAYLAND_wl_display_flush(c->display);
                 WAYLAND_wl_display_dispatch(c->display);
             }
@@ -2159,26 +2150,27 @@ void Wayland_HideWindow(SDL_VideoDevice *_this, SDL_Window *window)
     if (wind->shell_surface_type == WAYLAND_SHELL_SURFACE_TYPE_LIBDECOR) {
         if (wind->shell_surface.libdecor.frame) {
             libdecor_frame_unref(wind->shell_surface.libdecor.frame);
-            wind->shell_surface.libdecor.frame = NULL;
 
             SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_SURFACE_POINTER, NULL);
             SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_TOPLEVEL_POINTER, NULL);
         }
     } else
 #endif
+    {
         if (wind->shell_surface_type == WAYLAND_SHELL_SURFACE_TYPE_XDG_POPUP) {
-        Wayland_ReleasePopup(_this, window);
-    } else if (wind->shell_surface.xdg.toplevel.xdg_toplevel) {
-        xdg_toplevel_destroy(wind->shell_surface.xdg.toplevel.xdg_toplevel);
-        wind->shell_surface.xdg.toplevel.xdg_toplevel = NULL;
-        SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_TOPLEVEL_POINTER, NULL);
-    }
-    if (wind->shell_surface.xdg.surface) {
-        xdg_surface_destroy(wind->shell_surface.xdg.surface);
-        wind->shell_surface.xdg.surface = NULL;
-        SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_SURFACE_POINTER, NULL);
+            Wayland_ReleasePopup(_this, window);
+        } else if (wind->shell_surface.xdg.toplevel.xdg_toplevel) {
+            xdg_toplevel_destroy(wind->shell_surface.xdg.toplevel.xdg_toplevel);
+            SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_TOPLEVEL_POINTER, NULL);
+        }
+
+        if (wind->shell_surface.xdg.surface) {
+            xdg_surface_destroy(wind->shell_surface.xdg.surface);
+            SDL_SetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_XDG_SURFACE_POINTER, NULL);
+        }
     }
 
+    SDL_zero(wind->shell_surface);
     wind->show_hide_sync_required = true;
     struct wl_callback *cb = wl_display_sync(_this->internal->display);
     wl_callback_add_listener(cb, &show_hide_sync_listener, (void *)((uintptr_t)window->id));

src/video/wayland/SDL_waylandwindow.h

@@ -46,7 +46,6 @@ struct SDL_WindowData
         struct
         {
             struct libdecor_frame *frame;
-            bool initial_configure_seen;
         } libdecor;
 #endif
         struct
@@ -64,7 +63,6 @@ struct SDL_WindowData
                     struct xdg_positioner *xdg_positioner;
                 } popup;
             };
-            bool initial_configure_seen;
         } xdg;
     } shell_surface;
     enum