bug#26911: 25.2; eshell "cd .." doesn't work correctly with TRAMP

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

On 8/31/20 11:56 AM, Eli Zaretskii wrote:
>>> expand-file-name deals only with the syntax of file names.
>> Yes, but it does so under constraints imposed by semantics. This is why
>> expand-file-name can't simply remove*all*  slashes from file names (which would
>> be just a "syntax" thing, no? :-).
> No, because a valid syntax of an absolute file name is to start with a
> slash.

Ending with a slash is just as much syntax as starting with a slash is. The 
meaning (absolute versus relative for starting slash, or directory versus file 
for ending slash) is a consequence of the syntax in both cases. In neither case 
should expand-file-name remove the slash, unless it can determine that removing 
the slash does not change the meaning of the name (which it can do in some cases 
but not in all).

> We disagree.  So any further argument is fruitless

That's not a good way to resolve the disagreement. A better way is for me to see 
what changes you make or plan to make to expand-file-name. If these changes 
handle file names on GNU and POSIX platforms consistently with other GNU 
applications, everything will be OK. It's possible we are simply 
misunderstanding each other, after all.