[vtkusers] vtkUnstructuredGrid::InsertNextCell accessing NULL for empty ug

[Tim Tautges]

Hi all,
   If I have an "empty" vtkUnstructuredGrid, and call InsertNextCell on 
it, it causes the code to de-reference a NULL pointer.  I know I can 
just call Allocate on the ug, but (IMO) the application shouldn't need 
to check that.  It shouldn't be an efficiency concern either, as the 
code already has to check the allocation to see if it's big enough for 
the next cell, right?

- tim

-- 
================================================================
"You will keep in perfect peace him whose mind is
   steadfast, because he trusts in you."               Isaiah 26:3

              Tim Tautges            Sandia National Laboratories
          (tjtautg at sandia.gov)       (telecommuting from UW-Madison)
          phone: (608) 263-8485      1500 Engineering Dr.
            fax: (608) 263-4499      Madison, WI 53706-1609