Ummm No, that wasn’t the “first harry potter movie”.
Harry Potter’s dad was “James Potter”. Just because the names are similar, there was a witch involved, you can’t say that.
What is especially interesting and insightful about Troll was Gary Sandy's role -- one of his rare appearances outside of WKRP Cincinnati. Ms. Rowling, of course, had to change the name of Harry's father to appeal to British tastes.
June Lockhart played the witch.