[texhax] Puzzle: bibtex working when it *shouldn't*!!! ???

[Karl Berry]

    > Database file #1: references.bib.bib

I happened to (belatedly) notice this wrong output and fixed the code for this
year's release. That is, in the bibtex in TL'18, it should only report
Database file #1: references.bib.

BibTeX in TL has allowed an explicit .bib essentially forever (predating
TL), as I recall.

As for MiKTeX, maybe Christian will adopt the change to allow the
explicit .bib if you ask him, or maybe he's already rejected the idea.
FWIW, I think it would make sense. Just as one can say \input foo or
\input foo.tex ... --best, karl.