xdg-desktop-portal: fix paths

pkgs/development/libraries/xdg-desktop-portal/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, fetchpatch, autoreconfHook, pkgconfig, libxml2, glib, pipewire, fontconfig, flatpak, acl, dbus, fuse, wrapGAppsHook, gnome3 }:
+{ stdenv, fetchFromGitHub, substituteAll, autoreconfHook, pkgconfig, libxml2, glib, pipewire, fontconfig, flatpak, gsettings-desktop-schemas, acl, dbus, fuse, wrapGAppsHook }:
 
 stdenv.mkDerivation rec {
   pname = "xdg-desktop-portal";
@@ -15,10 +15,14 @@ stdenv.mkDerivation rec {
 
   patches = [
     ./respect-path-env-var.patch
+    (substituteAll {
+      src = ./fix-paths.patch;
+      inherit flatpak;
+    })
   ];
 
   nativeBuildInputs = [ autoreconfHook pkgconfig libxml2 wrapGAppsHook ];
-  buildInputs = [ glib pipewire fontconfig flatpak acl dbus fuse gnome3.gsettings-desktop-schemas ];
+  buildInputs = [ glib pipewire fontconfig flatpak acl dbus fuse gsettings-desktop-schemas ];
 
   doCheck = true; # XXX: investigate!
 

pkgs/development/libraries/xdg-desktop-portal/fix-paths.patch

@@ -0,0 +1,13 @@
+diff --git a/src/notification.c b/src/notification.c
+index 1367114..72ba033 100644
+--- a/src/notification.c
++++ b/src/notification.c
+@@ -401,7 +401,7 @@ validate_icon_more (GVariant *v)
+   int status;
+   g_autofree char *err = NULL;
+   g_autoptr(GError) error = NULL;
+-  const char *icon_validator = LIBEXECDIR "/flatpak-validate-icon";
++  const char *icon_validator = "@flatpak@/libexec/flatpak-validate-icon";
+   const char *args[6];
+
+   if (G_IS_THEMED_ICON (icon))