bug#27300: Subject: 25.2; (E)Shell command completion fails when folder in PATH is not readable

[Glenn Morris]

Bug reassigned to emacs (ended up in wrong package due to odd To: field
in original report).

Pierre Neidhardt wrote:

> - Make one PATH member non-readable
>
>       $ chmod -r /path/to/some/bin/folder
>
> - Start `emacs -Q`.
> - M-x shell
> - Press "e<TAB>" (any letter will do)
>
> I get the following error:
>
>       (file-error "Opening directory" "Permission denied" 
> "/path/to/some/bin/folder")
>
> While a warning could make sense, a non-readable folder should not prevent
> completion from working.