Series with short names like Rin or Magi are impossible to find in the integrated search feature. While the Magi has the affix "The Labyrinth of Magic" in MAL, Rin has nothing like it and currently it is impossible to find and update it through the app.
Rin on MAL: http://myanimelist.net/manga/46894/Rin
A long list of a bunch of stuff that is not Rin:

There's nothing I can do there. Those are the results returned by MAL's API. Try looking for the alternative name in the browser and try with that.
Unfortunately there is no alternative name. Maybe it is possible to make the list longer than it is currently to include more results?
http://myanimelist.net/modules.php?go=api#animemangasearch
I don't know if it's possible.
There's a way. I could show the list of the user (with a checkbox or something) and it could be selected there. I don't know how to design the dialog to do this in a friendly way though.
As of 8ca0814 you can search a manga from your list like this: my:rin
Can you please add some tooltip or any sort of hint so users don't have to look up this feature on github?
For example you could display a text like "Use my:
omg it helps me :lol
would be better if you put that
Just to be sure, regardless of the current MAL API status, was this feature removed ? It's still in the FAQ but I couldn't get it to work nor find the current code of the feature (a quick "getList" search in the repo returns nothing else than the function
itself available from MAL's workaround that was just merged, but I could have missed it somehow so I'd prefer to ask)
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Can you please add some tooltip or any sort of hint so users don't have to look up this feature on github?
For example you could display a text like "Use my: