Re: Emacs puts binary junk into the clipboard, marking it as text

[Kevin Rodgers]

Jan Djärv wrote:
> Chris Moore skrev:
> > Please describe exactly what actions triggered the bug
> > and the precise symptoms of the bug:
> >
> > I run the Xfce 4 desktop environment, along with the
> > xfce4-clipman-plugin applet which collects clipboard entries and
> > allows me to chose between them from a menu.
> >
> > I have x-select-enable-clipboard set to t in Emacs, so whenever I
> > 'kill' regions of the buffer, they get sent to the clipboard.
> >
> > Occasionally the clipman applet will start consuming all available
> > CPU.  This happens when I copy certain binary characters.  Seems the
> > clipman gets stuck in a loop trying to convert illegal an illegal UTF8
> > string.
> >
> > A very simple case which reproduces the bug:
> >
> > > I made a 1-byte file containing just character 0300 (octal),
> > > copied that using Emacs, and clipman started printing its error
> > > message over and over again.
> >
> > I reported this bug firstly to the Xfce BTS:
> >
> >   http://bugzilla.xfce.org/show_bug.cgi?id=1945
> >
> > but they told me it was a gtk bug, so I raised the same bug in the
> > GNOME tracker:
> >
> >   http://bugzilla.gnome.org/show_bug.cgi?id=349856
> >
> > and they tell me it's an Emacs bug, saying:
> >
> > > Well, if emacs puts binary junk into a text property it is not gtk's
> > fault.
> > > Look at gtk_selection_data_get_text(): We only try to convert
> > something to
> > > utf8 if the sender claims that it is text...
> >
> > So I'm raising it here too!
>
> Isn't 0300 a valid unicode character?

Yes, but it is not encoded as a single byte in UTF-8, it would be 2
bytes: o303 o200 (xC3 x80).

> Anyway, when Emacs gets a 
> selection request for the clipboard with type UTF8_STRING, it eventually 
> ends up in xselect-convert-to-string.  This function does:
>
>        ((eq type 'UTF8_STRING)
>         (setq str (encode-coding-string str 'utf-8)))
>
> As far as I can tell, it does not check if str is all text, it seems to 
> return  non-text unconverted.  Should we check str first?  And if it 
> does contain non-text, what should Emacs send back as type?  STRING, TEXT?

Doesn't that all depend on buffer-file-coding-system and
selection-coding-system being set correctly?

--
Kevin