Error messages must not be nested

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Review all locations where panic() and error() exist and try to get them to 
trigger. 
2. Any nested errors or panics must be eliminated

What is the expected output? What do you see instead?

A single un-nested panic or error. Preferably using the 4xx or 5xx series of 
errors

Please use labels and text to provide additional information.

Original issue reported on code.google.com by [email protected] on 12 Mar 2013 at 6:58