My document has an empty citation \cite{}. I'd expected to get some warning about it.

Is it a bug? (if not - why?) Is it possible to enable checking for such cases?

MWE:

\documentclass{article} \begin{document} \cite{Goodfellow2014a} \cite{} \bibliography{main} \bibliographystyle{plain} \end{document} 

and main.bib:

@misc{Goodfellow2014a, author = {Goodfellow, I J and Shlens, J and Szegedy, C}, title = {{Explaining and harnessing adversarial examples}}, year = {2014} } 

I'm using pdflatex and bibtex.