Re: Subclass Gio.DBusProxy and UnicodeDecodeError under python 3

[infirit <infirit gmail com>]

Op 12/27/2016 om 05:32 PM schreef infirit:
> Op 12/13/2016 om 04:31 PM schreef infirit:
> > Op 12/12/2016 om 11:49 PM schreef Christoph Reiter:
> > > On Sun, Dec 11, 2016 at 6:12 PM, infirit <infirit gmail com> wrote:
> > > > Hi all,
> > > >
> > > > I subclassed Gio.DBusProxy and overridden the do_g_properties_changed
> > > > virtual function. In there I emit my own signal that consumers of the
> > > > proxy can connect to. I have created a minimal example of what I am
> > > > doing which you can find on [1].
> > > >
> > > > The code from [1] runs perfectly fine under python2.7 with no
> > > > UnicodeDecodeError at any point, the situation under Python 3.4 however
> > > > is different. See below an example error. I narrowed it down to
> > > > overriding do_g_properties_changed, without that the error goes away.
> > > >
> > > >   *connected function* /org/bluez/hci0/dev_7C_2F_80_3B_AF_AB RSSI -64
> > > >   UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb8 in position
> > > > 0: invalid start byte
> > > >
> > > > The strange thing is that it does not generate a traceback so I am not
> > > > entirely sure how to proceed with this. It also does not seem to result
> > > > in issues however my gut tells me not to ignore it. Anyone know what is
> > > > going on with this?
> > > Under Python 2 text gets passed to Python as is (utf-8 encoded) while
> > > under Python 3 things get decoded to unicode code points. I suspect
> > > there is some invalid utf-8 involved which you should see in data
> > > getting passed to do_g_properties_changed under py2.
> > >
> > > I've tested your code (with adjusting the device path) and it seems to
> > > work fine under py3 here.
> > The problem is printing both properties changed and invalidated
> > properties is identical between the two python versions. The only
> > difference is with Python3 at the end I see the error. I monitored the
> > object from the command line (below) and I see all events back in my
> > proxy output. However there is something strange with the invalidated
> > properties, more on that down below.
> >
> > #gdbus -y -d "org.bluez" -o "/org/bluez/hci0/dev_7C_2F_80_3B_AF_AB"
> > /org/bluez/hci0/dev_7C_2F_80_3B_AF_AB:
> > org.freedesktop.DBus.Properties.PropertiesChanged ('org.bluez.Device1',
> > {'RSSI': <int16 -61>}, @as [])
> > /org/bluez/hci0/dev_7C_2F_80_3B_AF_AB:
> > org.freedesktop.DBus.Properties.PropertiesChanged ('org.bluez.Device1',
> > @a{sv} {}, ['RSSI'])
> >
> > Corresponding output from my code under python3
> >
> > *<class '__main__.MyProxy'> : changed*
> > /org/bluez/hci0/dev_7C_2F_80_3B_AF_AB RSSI -61
> > *connected function* /org/bluez/hci0/dev_7C_2F_80_3B_AF_AB RSSI -61
> > *invalidated* <class 'str'> ''
> > UnicodeDecodeError: 'utf-8' codec can't decode byte 0x90 in position 2:
> > invalid start byte
> >
> > and python2
> >
> > ("*<class '__main__.MyProxy'> : changed*",
> > '/org/bluez/hci0/dev_7C_2F_80_3B_AF_AB', 'RSSI', -61)
> > ('*connected function*', '/org/bluez/hci0/dev_7C_2F_80_3B_AF_AB',
> > 'RSSI', -61)
> > ('*invalidated*', <type 'str'>, "''", '')
> >
> > Now on the invalidated properties. I personally have need for them but I
> > did notice the virtual do_g_properties_changed is not handling them
> > properly. Take the second line from gdbus, it has no changed properties
> > and one invalidated property. Looking at what I get in
> > do_g_properties_changed I noticed I always get an empty *string*
> > (instead of a list). This looks like a bug as it is definitely on the
> > bus but never shows up in do_g_properties_changed. When I connect
> > directly (without using the virtual function) to g_properties_changed I
> > do see the invalidated properties correctly as a *list* of strings.
> >
> > My guess is that the two are related but I am not sure where to go from
> > here.
> Should I open a bug report?

There is already a bug report on it, see
https://bugzilla.gnome.org/show_bug.cgi?id=756009 but unfortunately the
bug is over a year old already :(.

~infirit