Undefined property: MW_OAuth::$last_res in api_v3.php

[Nicolas Raoul]

Using WikiShootMe, I found a picture of something that definitely needs a Wikidata item, and I made sure that no Wikidata item exists for it. So I decided to press the button "New Wikidata item based on this image". Unfortunately, nothing happened. The JavaScript console led me to this error:

Undefined property: MW_OAuth::$last_res in <b>/data/project/wikishootme/public_html/api_v3.php</b> on line <b>208</b>

Note: This only happens when not authorized. Ideally the user should be prompted to authorize, instead of failing silently.