[Spice-devel] [spice-gtk v1] gtk-session: reply agent's clipboard request on failure

[Victor Toso]

Hi,

On Fri, Feb 24, 2017 at 12:13:21PM +0100, Christophe de Dinechin wrote:
>
> > On 22 Feb 2017, at 13:29, Victor Toso <victortoso at redhat.com> wrote:
> >
> > From: Victor Toso <me at victortoso.com>
> >
> > We need to reply back to the agent all clipboard requests even in case
> > of failure otherwise it will have a pending request. The following
> > error message can be seen in afterwards, when client sends down some
> > clipboard data:
> >
> >> clipboard: selection requests pending on clipboard ownership
> >> change, clearing
> >
> > An easy way to reproduce this is:
> > 1-) In client, copy image from lo-draw (selection or ctrl+c)
>
> The patch looks good to me, but one thing I don’t understand is why
> you modify a function called “clipboard_received_text_cb” when the
> description of how to reproduce the bug is when you send an image. Is
> that callback used even for non-text data? If so, could we also rename
> it?

The problem is that the clipboard data that was requested is of TEXT
type. That will fail because we have an image in the clipboard.

These were the easiest way to reproduce I've found also aligned with the
https://bugzilla.redhat.com/show_bug.cgi?id=1409854#c0

> > 2-) In guest, paste it to GEdit (mouse3 our ctrl+v)
> > 3-) Move to the client
> > 4-) Move back to the guest
> > 5-) see error on vdagent logs
>
> Is this the only place where we see the error? Would it be possible to
> have a non-intrusive notification that the paste operation did not
> work and why?

We don't have this error on the spice-gtk nowadays. I think it would be
a good RFE but no clue on how to make it non-intrusive in the clients.

This is happening a lot with wayland even between two applications in
the client machine (e.g copying a url in gnome-terminal and pasting it
in the epiphany browser) - I don't see how it can inform user that
clipboard is failing there too :(

> > The reason for failure is that client's clipboard contains different
> > data type (image) then what was requested from guest's editor (text)
> >
> > While at it, include extra debug message as it might be hard to
> > identify why clipboard did not work.
>
> If it’s hard for you, imagine what it is for Joe
> MyGrandDadTheLinuxUser ;-)

:-)

>
> >
> > Resolves: rhbz#1409854
> > Signed-off-by: Victor Toso <victortoso at redhat.com>
> > ---
> > src/spice-gtk-session.c | 19 ++++++++++++-------
> > 1 file changed, 12 insertions(+), 7 deletions(-)
> > 
> > diff --git a/src/spice-gtk-session.c b/src/spice-gtk-session.c
> > index 0426d8f..315bc26 100644
> > --- a/src/spice-gtk-session.c
> > +++ b/src/spice-gtk-session.c
> > @@ -940,28 +940,33 @@ static void clipboard_received_text_cb(GtkClipboard *clipboard,
> >    if (self == NULL)
> >        return;
> > 
> > +    selection = get_selection_from_clipboard(self->priv, clipboard);
> > +    g_return_if_fail(selection != -1);
> > +
> >    if (text == NULL) {
> >        SPICE_DEBUG("Failed to retrieve clipboard text");
> > -        return;
> > +        goto notify_agent;
> >    }
> > 
> >    g_return_if_fail(SPICE_IS_GTK_SESSION(self));
> > 
> > -    selection = get_selection_from_clipboard(self->priv, clipboard);
> > -    g_return_if_fail(selection != -1);
> > -
> >    len = strlen(text);
> >    if (!check_clipboard_size_limits(self, len)) {
> > -        return;
> > +        SPICE_DEBUG("Failed sized limits of clipboard text (%d bytes)", len);
> > +        len = 0;
> > +        goto notify_agent;
> >    }
> > 
> >    /* gtk+ internal utf8 newline is always LF, even on windows */
> >    conv = fixup_clipboard_text(self, text, &len);
> >    if (!check_clipboard_size_limits(self, len)) {
> > -        g_free(conv);
> > -        return;
> > +        SPICE_DEBUG("Failed sized limits of clipboard text (%d bytes)", len);
> > +        g_clear_pointer(&conv, g_free);
> > +        len = 0;
> > +        goto notify_agent;
> >    }
> > 
> > +notify_agent:
> >    spice_main_clipboard_selection_notify(self->priv->main, selection,
> >                                          VD_AGENT_CLIPBOARD_UTF8_TEXT,
> >                                          (guchar *)(conv ?: text), len);
> > -- 
> > 2.9.3
> > 
> > _______________________________________________
> > Spice-devel mailing list
> > Spice-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/spice-devel
> 
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