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

[Kevin Rodgers <ihs_4664@yahoo.com>]

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