Re: [PATCH] Fix crash when HDP first reliable channel is nil

[Johan Hedberg <johan.hedberg@gmail.com>]

Hi Elvis,

On Tue, Mar 27, 2012, Elvis Pfutzenreuter wrote:
> On Mar 27, 2012, at 8:36 AM, Johan Hedberg wrote:
> 
> > Hi Elvis,
> > 
> > On Fri, Mar 16, 2012, Elvis Pfützenreuter wrote:
> >> Congruent to health_channel_destroy(), the "/" path is returned by MainChannel
> >> property of HealthDevice when the first reliable channel is nil.
> >> 
> >> An empty path provokes the following error:
> >> 
> >> process xxxs: arguments to dbus_message_iter_append_basic() were incorrect,
> >> assertion "_dbus_check_is_valid_path (*string_p)" failed in file
> >> ../../dbus/dbus-message.c line 2539.  This is normally a bug in some
> >> application using the D-Bus library.
> >> ---
> >> health/hdp.c |    2 +-
> >> 1 files changed, 1 insertions(+), 1 deletions(-)
> >> 
> >> diff --git a/health/hdp.c b/health/hdp.c
> >> index 812352f..eba438a 100644
> >> --- a/health/hdp.c
> >> +++ b/health/hdp.c
> >> @@ -2077,7 +2077,7 @@ static DBusMessage *device_get_properties(DBusConnection *conn,
> >> 	if (device->fr != NULL)
> >> 		path = g_strdup(device->fr->path);
> >> 	else
> >> -		path = g_strdup("");
> >> +		path = g_strdup("/");
> >> 	dict_append_entry(&dict, "MainChannel", DBUS_TYPE_OBJECT_PATH, &path);
> >> 	g_free(path);
> >> 	dbus_message_iter_close_container(&iter, &dict);
> > 
> > Would it maybe make more sense to simply not include this property in
> > the property list if device->fr is NULL? (after all, there's nothing
> > interesting to be found at "/" from a HDP perspective)
> > 
> 
> Could be, but when fr is deleted, a PropertyChanged signal is emitted for
> MainChannel. Is there some way to signal that a property has been removed?

Instead of sending a PropertyChanged wouldn't the ChannelDeleted signal
be good enough? (the client then just needs to compare it with the
currently known MainChannel value.

Johan