nisaddent causes a SIGSEGV error when adding to tnrhdb (4491941)

A SIGSEGV error is produced when using the nisaddent -avf command to add an incorrectly formatted file to the tnrhdb NIS+ map. This produces a core dump.

Workaround: The nisaddent command works correctly with a valid input file. To ensure that the input file has fields separated by colons and not by spaces, use niscat -s : when dumping a NIS+ table that will be used later as input to NIS+.