What is this method of joking about a morbid situation called?

What word or phrase could be used to describe a joke about something serious or bad? It isn't meant as humor in the typical sense, but as sort of a brave, different flavor of humor between two friends. Something that isnt actually funny, and could be really bad, but I choose to joke about it to dismiss fear. Between two people that accept life's events, and understand being morbid isn't going to change the matter at hand. For example:

"So we found out more about that chest problem my sister got checked for."

"So how long does she have?"

Gallows Humor

"humor that relates to very serious or frightening things (such as death and illness)"
-- Merriam-Webster

Personally, if I were to read this term or hear it in certain contexts, I would understand it. But I may not pick it up in conversation (even as a native speaker) because it is not an often-used term.

Dark humor is another very common term. I personally prefer it because it covers all the bases. Some people could interpret "black comedy" as something with a racist connotation, while "gallows humor" is suggestive of execution or death, even if it is more broadly used.

However, if you type "dark humor" into Wikipedia, it forwards you to an article about "black comedy."

Incidentally, "dark humor" yields a mere 365,000 hits in Google.