Please also provide the Varnish headers next time.
Will check though.

Including Varnish headers:

good:
{{{
$ wget -S -O /dev/null 'https://fedoraproject.org/wiki/Test_Results:Current_Installation_Test' 2>&1 | grep -E '(Location|ProxyServer|AppServer|Varnish)'
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150207_Installation?rd=Test_Results:Current_Installation_Test
AppServer: wiki02.phx2.fedoraproject.org
X-Varnish: 194264532 194262705
ProxyServer: proxy01.phx2.fedoraproject.org
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150207_Installation?rd=Test_Results:Current_Installation_Test [following]
AppServer: wiki01.phx2.fedoraproject.org
X-Varnish: 194264533 194262706
ProxyServer: proxy01.phx2.fedoraproject.org
}}}

bad:
{{{
$ wget -S -O /dev/null 'https://fedoraproject.org/wiki/Test_Results:Current_Installation_Test' 2>&1 | grep -E '(Location|ProxyServer|AppServer|Varnish)'
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150203_Installation?rd=Test_Results:Current_Installation_Test
AppServer: proxy06.fedoraproject.org
X-Varnish: 1491726 426520
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150203_Installation?rd=Test_Results:Current_Installation_Test [following]
AppServer: proxy06.fedoraproject.org
X-Varnish: 2401605 688339

$ wget -S -O /dev/null 'https://fedoraproject.org/wiki/Test_Results:Current_Installation_Test' 2>&1 | grep -E '(Location|ProxyServer|AppServer|Varnish)'
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150203_Installation?rd=Test_Results:Current_Installation_Test
AppServer: proxy08.fedoraproject.org
X-Varnish: 2527650 595105
Location: https://fedoraproject.org/wiki/Test_Results:Fedora_22_Rawhide_20150203_Installation?rd=Test_Results:Current_Installation_Test [following]
AppServer: proxy08.fedoraproject.org
X-Varnish: 2467959 595110
}}}

This instance has now been fixed, varnish had cached the wrong redirect.

This is a good reason to use the data from https://fedoraproject.org/wiki/Template:CurrentFedoraCompose rather than try to follow a redirect and parse the page name :)

in the 'Wikitcms' concept CurrentFedoraCompose is the canonical reference. I would actually like to have the Current redirect pages do something like:

{{{

REDIRECT [[Test Results: {{CurrentFedoraCompose}} Installation]]

}}}

but mediawiki cannot handle templates in redirects, unfortunately, so the redirects have to be updated along with CurrentFedoraCompose, but that's just a technical limitation.

of course the best answer is 'use python-wikitcms' :P