Enable support for wlshell

Sailfish still uses old wlshell and hasno support for modern xdg-shell.
Thispatch allows SDL to work on Sailfish.

Uplifted from github.com:savegame/SDL.git which in turn takes it from
https://github.com/sailfishos/libsdl/blob/master/rpm/0001-wayland-Bring-back-wl_shell-support.patch

include/SDL_syswm.h

@@ -294,7 +294,7 @@ struct SDL_SysWMinfo
         {
             struct wl_display *display;             /**< Wayland display */
             struct wl_surface *surface;             /**< Wayland surface */
-            void *shell_surface;                    /**< DEPRECATED Wayland shell_surface (window manager handle) */
+            struct wl_shell_surface *shell_surface; /**< DEPRECATED Wayland shell_surface (window manager handle) */
             struct wl_egl_window *egl_window;       /**< Wayland EGL window (native window) */
             struct xdg_surface *xdg_surface;        /**< Wayland xdg surface (window manager handle) */
             struct xdg_toplevel *xdg_toplevel;      /**< Wayland xdg toplevel role */

src/video/wayland/SDL_waylanddyn.h

@@ -111,11 +111,13 @@ void SDL_WAYLAND_UnloadSymbols(void);
 #define wl_shm_pool_interface            (*WAYLAND_wl_shm_pool_interface)
 #define wl_buffer_interface              (*WAYLAND_wl_buffer_interface)
 #define wl_registry_interface            (*WAYLAND_wl_registry_interface)
+#define wl_shell_surface_interface       (*WAYLAND_wl_shell_surface_interface)
 #define wl_region_interface              (*WAYLAND_wl_region_interface)
 #define wl_pointer_interface             (*WAYLAND_wl_pointer_interface)
 #define wl_keyboard_interface            (*WAYLAND_wl_keyboard_interface)
 #define wl_compositor_interface          (*WAYLAND_wl_compositor_interface)
 #define wl_output_interface              (*WAYLAND_wl_output_interface)
+#define wl_shell_interface               (*WAYLAND_wl_shell_interface)
 #define wl_shm_interface                 (*WAYLAND_wl_shm_interface)
 #define wl_data_device_interface         (*WAYLAND_wl_data_device_interface)
 #define wl_data_offer_interface          (*WAYLAND_wl_data_offer_interface)

src/video/wayland/SDL_waylandevents.c

@@ -543,6 +543,10 @@ static SDL_bool ProcessHitTest(struct SDL_WaylandInput *input, uint32_t serial)
                                       input->seat,
                                       serial);
                 }
+            } else {
+                if (window_data->shell_surface.wl) {
+                    wl_shell_surface_move(window_data->shell_surface.wl, input->seat, serial);
+                }
             }
             return SDL_TRUE;
 
@@ -568,6 +572,10 @@ static SDL_bool ProcessHitTest(struct SDL_WaylandInput *input, uint32_t serial)
                                         serial,
                                         directions[rc - SDL_HITTEST_RESIZE_TOPLEFT]);
                 }
+            } else {
+                if (window_data->shell_surface.wl) {
+                    wl_shell_surface_resize(window_data->shell_surface.wl, input->seat, serial, directions[rc - SDL_HITTEST_RESIZE_TOPLEFT]);
+                }
             }
             return SDL_TRUE;
 

src/video/wayland/SDL_waylandsym.h

@@ -101,11 +101,13 @@ SDL_WAYLAND_INTERFACE(wl_surface_interface)
 SDL_WAYLAND_INTERFACE(wl_shm_pool_interface)
 SDL_WAYLAND_INTERFACE(wl_buffer_interface)
 SDL_WAYLAND_INTERFACE(wl_registry_interface)
+SDL_WAYLAND_INTERFACE(wl_shell_surface_interface)
 SDL_WAYLAND_INTERFACE(wl_region_interface)
 SDL_WAYLAND_INTERFACE(wl_pointer_interface)
 SDL_WAYLAND_INTERFACE(wl_keyboard_interface)
 SDL_WAYLAND_INTERFACE(wl_compositor_interface)
 SDL_WAYLAND_INTERFACE(wl_output_interface)
+SDL_WAYLAND_INTERFACE(wl_shell_interface)
 SDL_WAYLAND_INTERFACE(wl_shm_interface)
 SDL_WAYLAND_INTERFACE(wl_data_device_interface)
 SDL_WAYLAND_INTERFACE(wl_data_source_interface)

src/video/wayland/SDL_waylandvideo.c

@@ -844,6 +844,8 @@ static void display_handle_global(void *data, struct wl_registry *registry, uint
     } else if (SDL_strcmp(interface, "xdg_wm_base") == 0) {
         d->shell.xdg = wl_registry_bind(d->registry, id, &xdg_wm_base_interface, SDL_min(version, 3));
         xdg_wm_base_add_listener(d->shell.xdg, &shell_listener_xdg, NULL);
+    } else if (SDL_strcmp(interface, "wl_shell") == 0) {
+        d->shell.wl = wl_registry_bind(d->registry, id, &wl_shell_interface, 1);
     } else if (SDL_strcmp(interface, "wl_shm") == 0) {
         d->shm = wl_registry_bind(registry, id, &wl_shm_interface, 1);
     } else if (SDL_strcmp(interface, "zwp_relative_pointer_manager_v1") == 0) {
@@ -1093,6 +1095,11 @@ static void Wayland_VideoCleanup(_THIS)
         data->shm = NULL;
     }
 
+    if (data->shell.wl) {
+        wl_shell_destroy(data->shell.wl);
+        data->shell.wl = NULL;
+    }
+
     if (data->shell.xdg) {
         xdg_wm_base_destroy(data->shell.xdg);
         data->shell.xdg = NULL;

src/video/wayland/SDL_waylandvideo.h

@@ -64,6 +64,7 @@ typedef struct
     struct
     {
         struct xdg_wm_base *xdg;
+        struct wl_shell *wl;
 #ifdef HAVE_LIBDECOR_H
         struct libdecor *libdecor;
 #endif

src/video/wayland/SDL_waylandwindow.c

@@ -383,6 +383,20 @@ static void SetFullscreen(SDL_Window *window, struct wl_output *output)
         } else {
             xdg_toplevel_unset_fullscreen(wind->shell_surface.xdg.roleobj.toplevel);
         }
+    } else {
+        if (wind->shell_surface.wl == NULL) {
+            return; /* Can't do anything yet, wait for ShowWindow */
+        }
+
+        wl_surface_commit(wind->surface);
+
+        if (output) {
+            wl_shell_surface_set_fullscreen(wind->shell_surface.wl,
+                                            WL_SHELL_SURFACE_FULLSCREEN_METHOD_DEFAULT,
+                                            0, output);
+        } else {
+            wl_shell_surface_set_toplevel(wind->shell_surface.wl);
+        }
     }
 }
 
@@ -478,6 +492,62 @@ static const struct wl_callback_listener gles_swap_frame_listener = {
 
 static void Wayland_HandleResize(SDL_Window *window, int width, int height, float scale);
 
+/* On modern desktops, we probably will use the xdg-shell protocol instead
+   of wl_shell, but wl_shell might be useful on older Wayland installs that
+   don't have the newer protocol, or embedded things that don't have a full
+   window manager. */
+
+static void
+handle_ping_wl_shell_surface(void *data, struct wl_shell_surface *shell_surface,
+            uint32_t serial)
+{
+    wl_shell_surface_pong(shell_surface, serial);
+}
+
+static void
+handle_configure_wl_shell_surface(void *data, struct wl_shell_surface *shell_surface,
+                 uint32_t edges, int32_t width, int32_t height)
+{
+    SDL_WindowData *wind = (SDL_WindowData *)data;
+    SDL_Window *window = wind->sdlwindow;
+
+    /* wl_shell_surface spec states that this is a suggestion.
+       Ignore if less than or greater than max/min size. */
+
+    if (width == 0 || height == 0) {
+        return;
+    }
+
+    if (!(window->flags & SDL_WINDOW_FULLSCREEN)) {
+        if ((window->flags & SDL_WINDOW_RESIZABLE)) {
+            if (window->max_w > 0) {
+                width = SDL_min(width, window->max_w);
+            }
+            width = SDL_max(width, window->min_w);
+
+            if (window->max_h > 0) {
+                height = SDL_min(height, window->max_h);
+            }
+            height = SDL_max(height, window->min_h);
+        } else {
+            return;
+        }
+    }
+
+    Wayland_HandleResize(window, width, height, wind->scale_factor);
+}
+
+static void
+handle_popup_done_wl_shell_surface(void *data, struct wl_shell_surface *shell_surface)
+{
+}
+
+static const struct wl_shell_surface_listener shell_surface_listener_wl = {
+    handle_ping_wl_shell_surface,
+    handle_configure_wl_shell_surface,
+    handle_popup_done_wl_shell_surface
+};
+
 static void handle_configure_xdg_shell_surface(void *data, struct xdg_surface *xdg, uint32_t serial)
 {
     SDL_WindowData *wind = (SDL_WindowData *)data;
@@ -1319,6 +1389,11 @@ void Wayland_ShowWindow(_THIS, SDL_Window *window)
 
             SetMinMaxDimensions(window, SDL_FALSE);
         }
+    } else {
+        data->shell_surface.wl = wl_shell_get_shell_surface(c->shell.wl, data->surface);
+        wl_shell_surface_set_class(data->shell_surface.wl, c->classname);
+        wl_shell_surface_set_user_data(data->shell_surface.wl, data);
+        wl_shell_surface_add_listener(data->shell_surface.wl, &shell_surface_listener_wl, data);
     }
 
     /* Restore state that was set prior to this call */
@@ -1494,6 +1569,11 @@ void Wayland_HideWindow(_THIS, SDL_Window *window)
             xdg_surface_destroy(wind->shell_surface.xdg.surface);
             wind->shell_surface.xdg.surface = NULL;
         }
+    } else {
+        if (wind->shell_surface.wl) {
+            wl_shell_surface_destroy(wind->shell_surface.wl);
+            wind->shell_surface.wl = NULL;
+        }
     }
 
     /*
@@ -1774,6 +1854,11 @@ void Wayland_RestoreWindow(_THIS, SDL_Window *window)
                 return; /* Can't do anything yet, wait for ShowWindow */
             }
             xdg_toplevel_unset_maximized(wind->shell_surface.xdg.roleobj.toplevel);
+        } else {
+            if (wind->shell_surface.wl == NULL) {
+                return; /* Can't do anything yet, wait for ShowWindow */
+            }
+            wl_shell_surface_set_toplevel(wind->shell_surface.wl);
         }
 
     WAYLAND_wl_display_roundtrip(viddata->display);
@@ -1853,6 +1938,11 @@ void Wayland_MaximizeWindow(_THIS, SDL_Window *window)
             return; /* Can't do anything yet, wait for ShowWindow */
         }
         xdg_toplevel_set_maximized(wind->shell_surface.xdg.roleobj.toplevel);
+    } else {
+        if (wind->shell_surface.wl == NULL) {
+            return; /* Can't do anything yet, wait for ShowWindow */
+        }
+        wl_shell_surface_set_maximized(wind->shell_surface.wl, NULL);
     }
 
     WAYLAND_wl_display_roundtrip(viddata->display);
@@ -2174,6 +2264,11 @@ void Wayland_SetWindowTitle(_THIS, SDL_Window *window)
             return; /* Can't do anything yet, wait for ShowWindow */
         }
         xdg_toplevel_set_title(wind->shell_surface.xdg.roleobj.toplevel, title);
+        } else {
+            if (wind->shell_surface.wl == NULL) {
+                return; /* Can'd do anything yet, wait for ShowWindow */
+            }
+            wl_shell_surface_set_title(wind->shell_surface.wl, title);
     }
 
     WAYLAND_wl_display_flush(viddata->display);

src/video/wayland/SDL_waylandwindow.h

@@ -67,6 +67,7 @@ typedef struct
             } roleobj;
             SDL_bool initial_configure_seen;
         } xdg;
+        struct wl_shell_surface *wl;
     } shell_surface;
     enum
     {