If residents of New York are known as New Yorkers, and residents of Paris are known as Parisians, what would residents of Shanghai be called?
I have received a document for comment that refers to Shanghai residents as "Shanghainese", but I would have thought this refers to the language that those of Shanghai speak. Any thoughts on this one?

It sounds to me like it would work as a title for the people also.

What about Shanghaians?

I think you should use Shanghainese...

People from France are called French and speak French, it's not an uncommon thing for language name and the demonym to be the same - there are many examples of this.

Read this: Demonym - Wikipedia, the free encyclopedia