[...] Request exceeded the limit of 10 internal redirects due to probable
      configuration error. Use 'LimitInternalRecursion' to increase the limit
      if necessary. Use 'LogLevel debug' to get a backtrace.

[...] r->uri = /user/foobar.php.php.php.php.php.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php.php
[...] redirected from r->uri = /user/foobar.php.php.php
[...] redirected from r->uri = /user/foobar.php.php
[...] redirected from r->uri = /user/foobar.php
[...] redirected from r->uri = /user/foobar