bug#28156: Emacs quietly munges symlink contents

[Paul Eggert <eggert@cs.ucla.edu>]

Eli Zaretskii wrote:
> What if readlink returns a name such as "/ssh:foo@bar:/quux"?  A
> symlink cannot have a remote file name as its target, can it?

A symlink target is a string, and can have any bytes in it (other than NUL). So 
if FOO is a remote file name then it can have FOO as a target. Of course the OS 
won't interpret the remote file name on its own, just as it won't interpret ~ or 
$ or whatever, but that is OK and expected.

> read-file-name gets the string from the user, so it's an entirely
> different context.

It was just one example, though it remains a good one. Another example is 
(directory-files dir), which does not escape its results even when they begin 
with ~. Really, there is no need or good precedent for the sort of escaping that 
you propose. It is much simpler (and agrees with the documentation and 
intuition) for file-symlink-p to return the results as-is, like directory-files 
does.