ccdefault.c:

ccdefault.c:
krb5_cc_default_name() is permitted to return a NULL
pointer as a valid output.  Passing a NULL pointer to
strcmp() will result in an exception as NULL is not
a valid input parameter to strcmp().

Save the output of krb5_cc_default_name() to a variable
and modify the conditional to set the new default ccache
name in the case where there is no existing default
ccache name.

ticket: 5080
tags: pullup

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@20551 dc483132-0cff-0310-8789-dd5450dbe970