\ensureascii should not use PU encoding (from hyperref with unicode option)

[jfbu]

Here is example

\documentclass[greek]{article}
\usepackage{babel}
%%%%\usepackage[LGR,T1]{fontenc}% from real use case but not needed for mwe
\usepackage[unicode]{hyperref}
\begin{document}
\show\ensureascii % should arguably use OT1, but uses PU which is not
                  % for typesetting to PDF

© % raises error

% \showoutput
\end{document}

The PU encoding is not intended for PDF typesetting only for bookmarks (I think). Same for PD1 when hyperref is used without option.

Should \ensureascii filter it out of candidate "ascii" encodings?

[u-fischer]

There are more non-ascii/non-text encodings around that are stored in the \BabelNonASCII and \BabelNonText lists. Probably it would be better to setup a positive list \BabelASCII instead.

[jbezos]

LGR and its non-LICR encoding, you know, Almost every issue involving \ensureascii is related to LGR. Maybe @u-fischer is right and a positive list is better (or even a combination of both).