bug#31272: 25.3; Directory with weird name cannot be opened via SFTP

[Christoph Michelbach]

When I try to open a directory with some weird character in its name on
an SSH resource via dired, Emacs does not show the contents of the
directory but instead opens a buffer for a new (empty) text file.

One of these directory names is "šbung" (without the quotes). Because
this weird character might not make it to you via email: The name is
"\232bung" or "C2 9A 62 75 6E 67" (in hexadecimal).

Opening a directory named like this via dired is no problem when its on
my local hard drive. On an SFTP resource, the problem always
occurs. It's not inherent to the directory where I discovered the
problem but inherent in the directory's name.