So the first return value from GetGuildRosterInfo() is the player name. Starting in today's patch, there is apparently an undocumented change: the player's name is always "fully qualified" with the realm name, even if the calling code is happening on the same realm as that of the player being indexed.
This makes complete sense, given the increased use of connected realms. Still, it would have been nice if they'd mentioned it beforehand. Or at all.
For Ambiguate, there's also the case where the auto-complete code passes the value of the "autoCompleteContext" key on the EditBox from which the auto-complete is being performed. The only place I can see that being set in FrameXML is in MailFrame.xml on line 630 where it is set to "mail". So, maybe that's a possibility, too.
It doesn't look like that function is defined in FrameXML or in any of the Blizzard addons, so I guess it's a C function? What avenue do we, as players (or even as addon authors), have to get any information on API functionality we can't see the source for? I know that some of the more prominent members of some WoW online communities seem to have ways to talk to people at Blizzard, but I've never heard any addon author say anything like that.
Additionally, is there a reason why Blizzard has never really done technical changelogs? (...at least, I don't remember them*)
------------- * Except maybe for one of the early expansions where I vaguely remember a nice thread in the UI & Macros forum with function signature changes and some discussion. It's possible that was a user thread, though. I don't remember.
Will return a result typical of what we're used to. It will remove your server name, and always keep foreign server names.
This one is a bit more intelligent. It will scan your guild roster for the name being passed. It removes the server names for any player being passed no matter what server they are on, as long as they are in your guild. i.e. you can't pass fake names and expect them to be trimmed.
There is a special case. If you have 2 players of the same name on different realms, the realm will be kept for both those players. This is what you will see happening in the Blizz guild panel.