wayland-surface: Don't do pending move/resizes on all commits

We assume in meta_window_wayland_move_resize that the next commit that
changes the geometry will always be for our next pending operation, so
if we have a move pending on a resize, the next commit will trigger the
move. This is, of course, fundamentally wrong.

We broke this assumption even more now that we don't fizzle out calls to
meta_window_move_resize_internal and now call it on every commit, which
means that a simple damage and then commit would complete a pending
move.

This was even broken by apps like weston-terminal, which, when clicking
on the maximize button, first redraws the terminal with the maximize
button state back on hover on press, and would only redraw when it got
the configure event with the coordinates.

To track the correct commit to apply the move for, we implement the
ack_configure request and ignore all move/resizes that happen before
that.

Right now, we actually fizzle out the entire move/resize if there's a
future pending configure we're waiting on.

src/wayland/meta-wayland-surface.c

@@ -243,7 +243,10 @@ toplevel_surface_commit (MetaWaylandSurface      *surface,
           return;
         }
 
-      meta_window_wayland_move_resize (window, geom, pending->dx, pending->dy);
+      meta_window_wayland_move_resize (window,
+                                       &surface->acked_configure_serial,
+                                       geom, pending->dx, pending->dy);
+      surface->acked_configure_serial.set = FALSE;
     }
 }
 
@@ -906,11 +909,10 @@ xdg_surface_ack_configure (struct wl_client *client,
                            struct wl_resource *resource,
                            uint32_t serial)
 {
-  /* Do nothing for now. In the future, we'd imagine that
+  MetaWaylandSurface *surface = wl_resource_get_user_data (resource);
-   * we'd ignore attaches when we have a state pending that
+
-   * we haven't had the client ACK'd, to prevent a race
+  surface->acked_configure_serial.set = TRUE;
-   * condition when we have an in-flight attach when the
+  surface->acked_configure_serial.value = serial;
-   * client gets the new state. */
 }
 
 static void
@@ -1811,7 +1813,8 @@ fill_states (struct wl_array *states, MetaWindow *window)
 void
 meta_wayland_surface_configure_notify (MetaWaylandSurface *surface,
                                        int                 new_width,
-                                       int                 new_height)
+                                       int                 new_height,
+                                       MetaWaylandSerial  *sent_serial)
 {
   if (surface->xdg_surface.resource)
     {
@@ -1832,6 +1835,12 @@ meta_wayland_surface_configure_notify (MetaWaylandSurface *surface,
       xdg_surface_send_configure (surface->xdg_surface.resource, new_width, new_height, &states, serial);
 
       wl_array_release (&states);
+
+      if (sent_serial)
+        {
+          sent_serial->set = TRUE;
+          sent_serial->value = serial;
+        }
     }
   else if (surface->wl_shell_surface.resource)
     wl_shell_surface_send_configure (surface->wl_shell_surface.resource,

src/wayland/meta-wayland-surface.h

@@ -31,6 +31,11 @@
 #include "meta-wayland-types.h"
 #include "meta-surface-actor.h"
 
+struct _MetaWaylandSerial {
+  gboolean set;
+  uint32_t value;
+};
+
 struct _MetaWaylandBuffer
 {
   struct wl_resource *resource;
@@ -113,6 +118,8 @@ struct _MetaWaylandSurface
 
   /* All the pending state that wl_surface.commit will apply. */
   MetaWaylandPendingState pending;
+
+  MetaWaylandSerial acked_configure_serial;
 };
 
 void                meta_wayland_shell_init     (MetaWaylandCompositor *compositor);
@@ -127,7 +134,8 @@ void                meta_wayland_surface_set_window (MetaWaylandSurface *surface
 
 void                meta_wayland_surface_configure_notify (MetaWaylandSurface *surface,
                                                            int                 width,
-							   int                 height);
+                                                           int                 height,
+                                                           MetaWaylandSerial  *sent_serial);
 
 void                meta_wayland_surface_ping (MetaWaylandSurface *surface,
                                                guint32             serial);

src/wayland/meta-wayland-types.h

@@ -36,4 +36,6 @@ typedef struct _MetaWaylandBufferReference MetaWaylandBufferReference;
 
 typedef struct _MetaWaylandSurface MetaWaylandSurface;
 
+typedef struct _MetaWaylandSerial MetaWaylandSerial;
+
 #endif

src/wayland/window-wayland.c

@@ -36,6 +36,7 @@ struct _MetaWindowWayland
 {
   MetaWindow parent;
 
+  MetaWaylandSerial pending_configure_serial;
   gboolean has_pending_move;
   int pending_move_x;
   int pending_move_y;
@@ -126,7 +127,8 @@ surface_state_changed (MetaWindow *window)
 
   meta_wayland_surface_configure_notify (window->surface,
                                          wl_window->last_sent_width,
-                                         wl_window->last_sent_height);
+                                         wl_window->last_sent_height,
+                                         &wl_window->pending_configure_serial);
 }
 
 static void
@@ -214,7 +216,8 @@ meta_window_wayland_move_resize_internal (MetaWindow                *window,
 
       meta_wayland_surface_configure_notify (window->surface,
                                              constrained_rect.width,
-                                             constrained_rect.height);
+                                             constrained_rect.height,
+                                             &wl_window->pending_configure_serial);
     }
   else
     {
@@ -350,6 +353,7 @@ meta_window_wayland_new (MetaDisplay        *display,
  */
 void
 meta_window_wayland_move_resize (MetaWindow        *window,
+                                 MetaWaylandSerial *acked_configure_serial,
                                  MetaRectangle      new_geom,
                                  int                dx,
                                  int                dy)
@@ -359,6 +363,22 @@ meta_window_wayland_move_resize (MetaWindow    *window,
   MetaRectangle rect;
   MetaMoveResizeFlags flags;
 
+  if (wl_window->pending_configure_serial.set)
+    {
+      /* If we're waiting for a configure and this isn't an ACK for
+       * any configure, then fizzle it out. */
+      if (!acked_configure_serial->set)
+        return;
+
+      /* If we're waiting for a configure and this isn't an ACK for
+       * the configure we're waiting for, then fizzle it out. */
+      if (acked_configure_serial->value != wl_window->pending_configure_serial.value)
+        return;
+
+      /* OK, this request is going to ACK the pending configure. */
+      wl_window->pending_configure_serial.set = FALSE;
+    }
+
   /* XXX: Find a better place to store the window geometry offsets. */
   window->custom_frame_extents.left = new_geom.x;
   window->custom_frame_extents.top = new_geom.y;

src/wayland/window-wayland.h

@@ -46,6 +46,7 @@ MetaWindow * meta_window_wayland_new       (MetaDisplay        *display,
                                             MetaWaylandSurface *surface);
 
 void meta_window_wayland_move_resize (MetaWindow        *window,
+                                      MetaWaylandSerial *acked_configure_serial,
                                       MetaRectangle      new_geom,
                                       int                dx,
                                       int                dy);