How to removeBack from a doubly linked list?

[joshgarza]

It tell's me I dereference a NULL pointer. I have marked where the error occurs.
https://pastebin.com/3tNP4Q2T

[ne555]

post a complete testcase, we need to be able to compile and run your program.
the problem may be somewhere else, like in enqueue().

by the way

         	head = NULL;
         	delete head; //delete NULL, that does nothing 

memory leak.