ANALYSIS:
=========
A LEX_STRING structure pointer is processed during the
validation of a stored program name. During this processing,
there is a possibility of null pointer dereference.

FIX:
====
check_routine_name() is invoked by the parser by supplying a
non-empty string as the SP name. To avoid any potential calls
to check_routine_name() with NULL value, a debug assert has
been added to catch such cases.