Display of UTF-8 encoded messages on tty fails for GNU Emacs

[Ulrich Müller]

In GNU Emacs (version 23.1), VM (version 8.0.12) cannot display UTF-8 mime-encoded messages on a tty. After decoding the message with vm-decode-mime-message, VM always shows the [Press RETURN to save to a file] button instead.

This is especially annoying since an increasing number of people send their mail labelled as UTF-8, even if they contain only characters from ASCII or ISO-8859-1.

Investigating the reason, I found that function vm-mime-tty-can-display-mime-charset always returns nil in GNU Emacs (because function console-tty-output-coding-system doesn't exist).

In my opinion things are over-engineered at this point: If the terminal cannot display single UTF-8 characters, there is no harm if a replacement character is displayed for them (and see above, many people are sending ASCII messages labelled as UTF-8, where display is not a problem). OTOH, for users in countries with a non-european writing system it is unlikely that the terminal wouldn't be able to display them.

A patch for vm-mime-charset-internally-displayable-p is attached.