Hello,
I have done a lot of research regarding this problem and I posted
everything I collected in the appropriate ticket in pidgin, see [1].
The conclusion is the following:
The problem was probably introduced by an update of the software on
the server side around mid 2009. All contacts added after that time
did not get the "Has you" flag properly set. I got into contact with
Microsoft's MSN Messenger support team regarding this problem and
after giving me a number of more or less useful hints, they admitted
that there is a problem with Messenger and that it is going to be
fixed in the next major release (which was "Windows Live Messenger
2011"). I posted their answers in [1] and other bug reports linked
there-in.
What they actually did in WLM2011, is that they removed the
possibility in WLM2011 to view the list of people who have oneself in
their list. However, the feature is still present in the recently
released version for MacOS X ("Messenger for Mac 8") and does indeed
work. Adding a contact in the Mac version will set the "Has you" flag
to "Yes". This also works between WLM2009 and the Mac
version. However, it does not work when either side is using
WLM2011. Obviously WLM2011 is ignoring the flag completely and also
does not alter it even though the server software still understands
the flag and it can be set and unset.
Setting the flag has not working at all in most cases until recently
so I suppose that Microsoft fixed the software on the server side
since they didn't release any new version of WLM2009 as far as I
know. And I definitely observed that the flag was not set properly
when using WLM2009 up until recently.
With Pidgin, the case is a bit difficult. I have recently tested with
pidgin 2.7.4 and I have observed that even though the "Has you" flag
is properly set to "Yes" for one of the chat parties when adding a
contact, it might still show "No" on the other side. Thus, when A adds
B in MSN, Pidgin might report "B has you: Yes" for A but not vice
versa ("A has you: No"). I have not yet figured out what influences
the setting of the flag when using Pidgin but once I know more, I will
let you know.
To cut a long story short: The feature works correctly with the
current version for MacOS ("Messenger for Mac 8") and "Windows Live
Messenger 2009". It is not set and ignored by "Windows Live Messenger
2011". And on Pidgin, the flag might only be set for one of the two
parties when adding a contact.
My suggestion would therefore be to not remove the "Has you" flag from
Pidgin since the server software still recognizes it and one can
always assume that if the flag is set to "Yes" that the information is
correct and the other contact has added oneself into his/her contact
list.
When the flag shows "No", the information might not be correct,
i.e. one is actually in the contact list of the other party but still
listed as "Has you: No" which is due to either of the parties' clients
failing to properly setting the "Has you" flag to "Yes" which might
happen when using Pidgin when adding a contact, always happens when
using WLM2011 and never happens, i.e. works properly, when using
WLM2009 or Messenger for Mac 8.
So there *might* be a bug in Pidgin where it does not exactly behave
like the original clients WLM2009/Messenger for Mac 8 and WLM2011 does
not support the flag anymore.
Regards,
Adrian
[1] http://developer.pidgin.im/ticket/10681