Created attachment 10894 [details]
Simple test pydcop program

Quite possibly a problem, I never tested the bindings with non-ASCII characters. Does it work if you use a python Unicode string?
I'll try to look into this over the next week.

If I add:

query = query.decode('utf-8')

I get an unknown method error:

hugo@jibboom /tmp% python test.py é
SELECT count(*) FROM tags WHERE url LIKE "%é%"
<type 'unicode'>
Traceback (most recent call last):
  File "test.py", line 9, in ?
    print pydcop.anyAppCalled("amarok").collection.query(query )
  File "/usr/lib/python2.3/site-packages/pydcop.py", line 90, in __call__
    return pcop.dcop_call( self.appname, self.objname, self.name, args )
RuntimeError: DCOP: Unknown method.

I'll attach the updated test.py.

Created attachment 10904 [details]
Same script, but converting the query string to Unicode

Confirmed on KDE 3.5.2
This happens on any pydcop call, if I try to use unicode strings the "DCOP: Unknown method" runtime error is raised. If I use non-unicode strings, national characters are interpreted as 8 bit ascii.
This makes pydcop unusable for internacionalized projects
Example:
pydcop.anyAppCalled('amarok').scripts.addCustomMenuItem(u'á','b') ->Exception
pydcop.anyAppCalled('amarok').scripts.addCustomMenuItem('á','b') ->wrong characters

As a side note, pykde's dcop extension doesn't have this  problem (it has many others, though)

The problem still shows up now.
In fact, it displays UTF-8 strings as if they were iso-8859-15.

Example:
>>> import pcop
>>> pcop.dcop_call('knotify', 'default', 'notify', ('Event Foo', 'App Bar', 'é', '', '', 16, 0))

This gives a popup containing "é" instead of "é", which means that the 2 bytes of the utf-8 character are interpretated as 2 separate 8-bit characters.

Please note that my system charset is UTF-8.

KDE 3.5.4
Python 2.4.4c0 (Debian sid package 2.4.3-11)
python-dcop (Debian sid package 4:3.5.3-1+b1)

-- 
David Ammouial

*** This bug has been confirmed by popular vote. ***

hmm ok i think i have found the problem (and solved it ;) )

my system:
fedora core 6(x86_64)
kdebindings-3.5.5-0.1.fc6

it is not related to pydcop.py (which is only a small wrapper around pcop.so)
it is a bug in the marshal modul of pcop.so

kdebindings-3.5.5/dcoppython/shell/marshal_funcs.data
around line 250

there is the conversion spec for QString which looks like:

type:QString
%doc as str s
%% marshal
  {
    if (!PyString_Check(obj)) return false;
    if (str) {
      QString s( PyString_AsString(obj) );          //<<<---bug---<<<<
      (*str) << s;
    }
    return true;
  }
%% demarshal
  {
    QString s;
    (*str) >> s;
    return PyString_FromString( s.utf8().data() );
  }
%%

at line 250 the function uses the default constructor of QString
which expects a Latin-1 char* string

"""The encoding is assumed to be Latin-1, unless you change it using QTextCodec::setCodecForCStrings().""" <from qt docs>

i think a simple change in 
   QString s = QString::fromUtf8( PyString_AsString(obj) );
should be ok

here my suggestion:

type:QString
%doc as str s
%% marshal
  {
    if (!PyString_Check(obj)) return false;
    if (str) {
      QString s = QString::fromUtf8( PyString_AsString(obj) );
      (*str) << s;
    }
    return true;
  }
%% demarshal
  {
    QString s;
    (*str) >> s;
    return PyString_FromString( s.utf8().data() );
  }
%%

Christian, could you upload a patch with your fix?

Created attachment 18469 [details]
patch for QString conversion of dcop python binding

ok

i'am sure that this patch solves the problem but
there may be other conversions (e.g. type:KURL and uchar)
also suffering from such problems but i couldn't trigger a bug there
(not enough time to test)
so i decided not to change anything there ;)

i think that someone should review the whole marshal code regarding this problems

but i'am happy if the patch could be applied to the next version ;)
"cause i'am writing a new program using it" ;)

thx

Could anybody apply this patch in kde source code?

Closing as DCOP is unmaintained.