Issue reported by janne-hmp: examining an object on the map while
halluicinating might operate on an object whose name is Null since the
random object could be one that holds an extra description for item
shuffling at game start. Attempting to format the object led to a
crash.
I wasn't able to reproduce the crash, possibly because MacOS produces
the string "(null)" for sprintf("%s",NULL) instead of dereferencing
the Null pointer.
Perhaps random object selection for display should reject the extra
description objects in some classes. This susbstitutes a different
object if examining the map encounters one of those.
Fixes#1436
407a2e0ea8