[mutter] wayland/gtk: Only perform allowed titlebar gestures

[Marge Bot <marge-bot src gnome org>]

commit 7ff52b612838f95556d061c44a62512d7fcf0a96
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Feb 10 19:51:16 2022 +0100

    wayland/gtk: Only perform allowed titlebar gestures
    
    The window functions "work" regardless of whether the client allows
    the behavior or not. That is, it's up to the caller to not call
    maximize and friends when the action isn't allowed.
    
    Add appropriate checks, which should make the titlebar_gesture()
    behavior identical to titlebar actions for server-side decorations.
    
    https://gitlab.gnome.org/GNOME/mutter/-/issues/2139
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2281>

 src/wayland/meta-wayland-gtk-shell.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/src/wayland/meta-wayland-gtk-shell.c b/src/wayland/meta-wayland-gtk-shell.c
index 1ec5ffdf45..3d85c3f887 100644
--- a/src/wayland/meta-wayland-gtk-shell.c
+++ b/src/wayland/meta-wayland-gtk-shell.c
@@ -253,6 +253,9 @@ gtk_surface_titlebar_gesture (struct wl_client   *client,
   switch (action)
     {
     case G_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE:
+      if (!window->has_maximize_func)
+        break;
+
       if (META_WINDOW_MAXIMIZED (window))
         meta_window_unmaximize (window, META_MAXIMIZE_BOTH);
       else
@@ -260,6 +263,9 @@ gtk_surface_titlebar_gesture (struct wl_client   *client,
       break;
 
     case G_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE_HORIZONTALLY:
+      if (!window->has_maximize_func)
+        break;
+
       if (META_WINDOW_MAXIMIZED_HORIZONTALLY (window))
         meta_window_unmaximize (window, META_MAXIMIZE_HORIZONTAL);
       else
@@ -267,6 +273,9 @@ gtk_surface_titlebar_gesture (struct wl_client   *client,
       break;
 
     case G_DESKTOP_TITLEBAR_ACTION_TOGGLE_MAXIMIZE_VERTICALLY:
+      if (!window->has_maximize_func)
+        break;
+
       if (META_WINDOW_MAXIMIZED_VERTICALLY (window))
         meta_window_unmaximize (window, META_MAXIMIZE_VERTICAL);
       else
@@ -274,6 +283,9 @@ gtk_surface_titlebar_gesture (struct wl_client   *client,
       break;
 
     case G_DESKTOP_TITLEBAR_ACTION_MINIMIZE:
+      if (!window->has_minimize_func)
+        break;
+
       meta_window_minimize (window);
       break;