How to be more careful about null pointers?

[cy via Digitalmars-d-learn]

I finally found the null pointer. It took a week. I was assigning 
"db = db" when I should have been assigning "this.db = db". 
Terrible, I know. But...

I invoked db.find_chapter.bindAll(8,4), when db was a null 
pointer. There was no null pointer error. No exception raised for 
dereferencing a null. I'm not in release mode. Assertions are 
enabled. Shouldn't that have raised a null pointer exception?

Instead, it accesses db as if db were not null, producing a 
garbage structure in find_chapter, which bindAll chokes on, then 
causes the whole program to segfault.

I realize enforce(db).find_chapter would work, but... I thought D 
was more careful about null pointers? At least enough to die on 
dereferencing them?