Comment 2 for bug 1956195

I'm not sure what path it is trying to use. Another Flatpak app gives me paths that look like this: /run/user/1001/doc/4c9c5fa0/

If I load a file from disk and then do a Save As (so, in theory I know it's using a valid path) I still get an unhandled exception:

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> GLib.GException: Invalid byte sequence in conversion input
   at GLib.Marshaller.StringToFilenamePtr(String str)
   at Gtk.FileChooserAdapter.SetCurrentFolder(String filename)
   at Pinta.Actions.SaveDocumentImplmentationAction.SaveFileAs(Document document)
   at Pinta.Actions.SaveDocumentImplmentationAction.Activated(Object sender, DocumentCancelEventArgs e)
   at Pinta.Core.FileActions.RaiseSaveDocument(Document document, Boolean saveAs)
   at Pinta.Core.Document.Save(Boolean saveAs)
   at Pinta.Actions.SaveDocumentAsAction.Activated(Object sender, EventArgs e)
   at Pinta.Core.Command.<.ctor>b__33_0(Object o, ActivatedArgs args)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Span`1& arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at System.Delegate.DynamicInvoke(Object[] args)
   at GLib.Signal.ClosureInvokedCB(Object o, ClosureInvokedArgs args)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)