bug#10489: 24.0.92; dired-do-copy may create infinite directory hierarchy

[Stefan Monnier]

>>> Maybe we could change the entry in files.texi like this:
>> [...]
>>> @defun file-equal-p file1 file2
>>> This function returns @code{t} if the files @var{file1} and
>>> ! @var{file2} name the same file.  If @var{file1} or @var{file2} does
>>> ! not exist, the return value is unspecified.
>> 
>> That looks good.
> What can be done also is to return a string in this case.
> So possible return values could be e.g:
> "unspecified" => mean one of the files doesn't exists.
> nil           => files exist and are not equal
> t             => files exist and are equal.

No, we may decide in the future to return a particular value (maybe not
always the same one), but we don't know yet what might be useful, so
instead we say it's not specified.


        Stefan