Prefer xdgdesktopportal to better integration file dialogs

client/main.cpp

@@ -26,6 +26,22 @@
 
 int main( int argc, char *argv[] )
 {
+#ifdef Q_OS_LINUX
+	// On GNOME Qt picks the GTK3 platform theme, whose file chooser hard-codes
+	// gtk_file_chooser_set_local_only(true). That hides every location without a
+	// native path, so gvfs network mounts (NAS over SFTP/SMB, added in Files) are
+	// missing from the save dialog even though they are mounted and writable.
+	// The xdg-desktop-portal chooser is GTK4, which dropped local_only entirely,
+	// so it lists them. Qt never selects that theme on its own, hence the override.
+	//
+	// Requires qt6-xdgdesktopportal-platformtheme (a Recommends of this package).
+	// If it is missing Qt falls through to gtk3, i.e. the previous behaviour, so
+	// tell users who cannot see a network location in the save dialog to install
+	// that package. Setting QT_QPA_PLATFORMTHEME yourself overrides this.
+	if(qEnvironmentVariableIsEmpty("QT_QPA_PLATFORMTHEME"))
+		qputenv("QT_QPA_PLATFORMTHEME", "xdgdesktopportal");
+#endif
+
 	for(int i = 1; i < argc; ++i)
 	{
 		QString parameter(argv[i]);

debian/control

@@ -27,6 +27,7 @@ Depends:
  ${shlibs:Depends},
  ${misc:Depends}
 Recommends:
+ qt6-xdgdesktopportal-platformtheme,
  python3-nautilus:amd64 | python3-nautilus:arm64
 Replaces:
  qdigidoc (<< 3.14)