undrop: limit the length of password. (Fixes a crash.)
krb5: ensure that username and realm are non-empty. (Fixes SIGFPE.)
Merge branch 'bleeding-jumbo' into memdbg

* bleeding-jumbo:
  krb5: ensure that username and realm are non-empty. (Fixes SIGFPE.)
  undrop: limit the length of password. (Fixes a crash.)