1461759 - [snap] Opening a file with "Url Handler Script" does nothing

Status: RESOLVED WORKSFORME

(Release Engineering Graveyard :: Release Automation: Snap, defect)

Description

[Olivier Tilloy]

Attachment: url-handler-script.png

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.40 Safari/537.36

Steps to reproduce:

(issue initially reported on the snapcraft forum: https://forum.snapcraft.io/t/firefox-url-handler-does-nothing/5329)

1) snap run firefox
2) click on a link to e.g. a .doc file
3) the default action proposed to the user is to open the file with "Url Handler Script" (see attached screenshot), click OK to do that


Actual results:

Nothing happens, the document is not opened.
Seeing the following error in terminal:

    user-open error: no such file or directory


Expected results:

The file should be opened with whatever the default application for its mimetype is (e.g. libreoffice for a doc file).

Comment 1

[Harald H.]

Sample for #2: https://extensions.libreoffice.org/templates/basic-personal-letter-1/1.0

Comment 2

[Kanchan Kumari QA]

I could reproduce this issue with snap run firefox. I get option to open doc with "Url Handler Script" and after clicking 'OK' doc is not opened and terminal shows 'user-open error: no such file or directory'.

Placing this under Firefox:Shell Integration so someone can look into it. Feel free to change this to more appropriate component.

Comment 3

[work.gaetan.quentin]

+1

Comment 5

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

Snap's sandbox, not ours.

I assume the Snap environment has some way for an application to ask for a file to be opened in another app, but I don't know the details.

Comment 6

[Olivier Tilloy]

Yes, the blessed way for snaps to open a file is to call xdg-open, which is being proxied (after a few sanity checks) to outside the snap confinement.

As I understand it, firefox doesn't use xdg-open, instead it tries to query the system for applications that can handle a certain file type. This will fail in a strictly confined snap where this would be considered an information leak.

Comment 7

[Emerson Bernier]

Firefox does use xdg-open if it's chosen as target application. The problem is that FF always save the file to /tmp or $TMPDIR before passing it over and /tmp in snap is being namespaced and inaccessible for anything outside snap sandbox. If the $TMPDIR would be set to some other path like $TMPDIR=$"SNAP_USER_DATA" in desktop-launcher the problem may be gone.

Comment 8

[Emerson Bernier]

sorry, it should be "export TMPDIR=$"$SNAP_USER_DATA"

Comment 9

[Olivier Tilloy]

I tested this again on a variety of Ubuntu releases, and I'm not seeing this "Url Handler Script" option any longer, when opening files that are not handled by Firefox directly. Instead the default option in the dialog is "System Handler", and it does the right thing.

This bug can be closed.

Comment 10

[Julien Cristau [:jcristau]]

Closing per comment 9.