A function with /return fail run in chat doesn't indicate failure

If a function containing /return fail is run in chat, it returns a success of 1.

How to reproduce:

The attached data pack contains a function named bugtest:fail that runs /return fail.
Run the function with an "execute store result" and an "execute store success".

Observed behavior:

In chat, the message "Function bugtest:fail returned 0" appears and the result is 0 but the success 1.

Expected behavior:

A message "Function bugtest:fail failed" or similar should appear and result and success should both be 0 indicating failure.