When a user name contains a '>' the configuration cannot be saved.

Example: User Name <username@example.com>

hudson.util.IOException2: Failed to create a temporary file in C:\dev\hudson\users\User Name _username@example.com>
at hudson.util.AtomicFileWriter.(AtomicFileWriter.java:67)
at hudson.util.AtomicFileWriter.(AtomicFileWriter.java:54)
at hudson.XmlFile.write(XmlFile.java:162)
at hudson.model.User.save(User.java:407)

The prefix '<' is replaced with underscore, but not the closing brace.

Expected:

Save config to C:\dev\hudson\users\User Name username@example.com

Looks to be a problem in User.java.
svn patch from 1.348 tag attached.