xdg-shell: update shsurf->output when maximizing

shsurf->output is the output that user expects the shell surface
is on. When maximizing, we don't have any explicit setting of the output
like in the case of fullscreening, so set the output to the one that
the surface is currently on. In the case that the surface is not mapped yet,
(if it ever happens) use the same heuristics as for fullscreening.

This fixes the size sent with configure event, when maximizing a window.
The size is now picked up by the correct output, but the maximized
window position is still wrong. [Pekka Paalanen]

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=82967
Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

desktop-shell/shell.c

@@ -3541,6 +3541,32 @@ get_primary_view(void *shell, struct shell_surface *shsurf)
 	return shsurf->view;
 }
 
+static struct weston_output *
+get_focused_output(struct weston_compositor *compositor)
+{
+	struct weston_seat *seat;
+	struct weston_output *output = NULL;
+
+	wl_list_for_each(seat, &compositor->seat_list, link) {
+		/* Priority has touch focus, then pointer and
+		 * then keyboard focus. We should probably have
+		 * three for loops and check frist for touch,
+		 * then for pointer, etc. but unless somebody has some
+		 * objections, I think this is sufficient. */
+		if (seat->touch && seat->touch->focus)
+			output = seat->touch->focus->output;
+		else if (seat->pointer && seat->pointer->focus)
+			output = seat->pointer->focus->output;
+		else if (seat->keyboard && seat->keyboard->focus)
+			output = seat->keyboard->focus->output;
+
+		if (output)
+			break;
+	}
+
+	return output;
+}
+
 static void
 shell_get_shell_surface(struct wl_client *client,
 			struct wl_resource *resource,
@@ -3696,9 +3722,17 @@ xdg_surface_set_maximized(struct wl_client *client,
 			  struct wl_resource *resource)
 {
 	struct shell_surface *shsurf = wl_resource_get_user_data(resource);
+	struct weston_output *output;
 
 	shsurf->state_requested = true;
 	shsurf->requested_state.maximized = true;
+
+	if (!weston_surface_is_mapped(shsurf->surface))
+		output = get_focused_output(shsurf->surface->compositor);
+	else
+		output = shsurf->surface->output;
+
+	shell_surface_set_output(shsurf, output);
  	send_configure_for_surface(shsurf);
 }
 
@@ -3713,32 +3747,6 @@ xdg_surface_unset_maximized(struct wl_client *client,
 	send_configure_for_surface(shsurf);
 }
 
-static struct weston_output *
-get_focused_output(struct weston_compositor *compositor)
-{
-	struct weston_seat *seat;
-	struct weston_output *output = NULL;
-
-	wl_list_for_each(seat, &compositor->seat_list, link) {
-		/* Priority has touch focus, then pointer and
-		 * then keyboard focus. We should probably have
-		 * three for loops and check frist for touch,
-		 * then for pointer, etc. but unless somebody has some
-		 * objections, I think this is sufficient. */
-		if (seat->touch && seat->touch->focus)
-			output = seat->touch->focus->output;
-		else if (seat->pointer && seat->pointer->focus)
-			output = seat->pointer->focus->output;
-		else if (seat->keyboard && seat->keyboard->focus)
-			output = seat->keyboard->focus->output;
-
-		if (output)
-			break;
-	}
-
-	return output;
-}
-
 static void
 xdg_surface_set_fullscreen(struct wl_client *client,
 			   struct wl_resource *resource,