When logging into phpmyadmin at an ipv6 IP address, the redirect upon login mangles the URL. Specifically, it does the following:
http://\[2001:470:e130:f001::f001]/phpmyadmin will redirect to
http://\[2001:470/phpmyadmin//index.php?token={blahblahblah}
If the correct IP address (and required enclosing brackets) is restored and the page loaded (presuming correct login credentials were submitted), phpmyadmin works correctly thereafter. It is ONLY the processing of the URL for redirection immediately following a login attempt that exhibits this error. My guess is that the URL parsing is keying off the first colon found, expecting that what follows is a port number.
Confirmed.
As a temporary fix $cfg['PmaAbsoluteUri'] could be set to avoid this problem.
A fix is in the making, but needs a little more testing.
Fixed in subversion, thanks for reporting.