Failed to open file chooser when trying to save with a SVG opened

[UbuntuOne]

1. Open a SVG file in Pinta.
2. File -> Save As...

```
$ pinta

(pinta:32488): GdkPixbuf-CRITICAL **: 13:20:44.867: gdk_pixbuf_calculate_rowstride: assertion 'width > 0' failed

(pinta:32488): GdkPixbuf-CRITICAL **: 13:20:44.867: gdk_pixbuf_calculate_rowstride: assertion 'width > 0' failed

(pinta:32488): GLib-GIO-WARNING **: 13:20:49.650: Error creating IO channel for /proc/self/mountinfo: Permission denied (g-file-error-quark, 2)

(pinta:32488): GLib-GIO-WARNING **: 13:20:58.229: Error creating IO channel for /proc/self/mountinfo: Permission denied (g-file-error-quark, 2)

(pinta:32488): Gtk-WARNING **: 13:20:58.321: Can't open portal file chooser: GDBus.Error:org.freedesktop.portal.Error.InvalidArgument: current_filter, if specified, must be present in filters list if list is nonempty
```

[Cameron White (cameronwhite91)]

I can reproduce this only with snap / flatpak packages. The file chooser portal seems to error out if the file filter isn't set to a valid filter, which in this case happens because SVG files can be read but can't be written to

[Cameron White (cameronwhite91)]

Fixed by https://github.com/PintaProject/Pinta/commit/404246ddbe47ef0a9b1a4ee7b17097fed2ade8cd

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Matthew Bright (matt1003)]

I am still seeing the same issue despite using the latest version of Pinta available via snap:

snap info pinta
name: pinta
summary: Painting made simple!
publisher: James Carroll✪
store-url: https://snapcraft.io/pinta
contact: https://github.com/JGCarroll
license: MIT
description: |
  Pinta is a freely licensed and cross platform simple drawing application. It is designed in lieu
  of Paint.NET; being both simple to use and powerful for a wide variety of image manipulation
  purposes.
commands:
  - pinta
snap-id: BjE9sgvAgtIBuxSaYGdEuJOVoOZGsz0s
tracking: latest/stable
refresh-date: today at 15:43 NZDT
channels:
  latest/stable: 2.1.2 2024-09-18 (37) 53MB -
  latest/candidate: ↑
  latest/beta: ↑
  latest/edge: ↑
installed: 2.1.2 (37) 53MB -

I am seeing the same error when trying to open/save files:

(pinta:424463): GLib-GIO-WARNING **: 15:48:28.634: Error creating IO channel for /proc/self/mountinfo: Permission denied (g-file-error-quark, 2)

[Matthew Bright (matt1003)]

My bad. Apparently my system was missing the portal required for the file picker.

Was able to fix my issue with the following command:

sudo apt install xdg-desktop-portal-gtk