vchoi_fork

[svn-r11277] Purpose:
    Bug fix

Description:
    Fix core dump when checking whether to invalidate the name of an object
when unlinking an object in a group opened through an object reference.

Solution:
    Check if names of various objects are valid before comparing them, etc.

Platforms tested:
    FreeBSD 4.11 (sleipnir)
    Too minor to require h5committest