Last modified: 2013-04-22 16:16:38 UTC
Split of from bug 44162. The current behaviour can be confusing to users who arrive via links and get something totally different displayed.
Clarification: ?tux=0 shows an error message; ?tux=1 shows a mostly blank page with no indication of the problem.
Patch: https://gerrit.wikimedia.org/r/#/c/54212/