bug#42538: 28.0.50; tramp-test35-remote-path test timing out on macOS

[Michael Albinus]

Philipp Stephani <p.stephani2@gmail.com> writes:

Hi Philipp,

> And some more errors:
>
> Test tramp-test41-utf8 condition:
>     (file-error "Couldn't write region to
> `/mock:p:/private/var/folders/ks/sxl3n3w51td0ry21j3tjs1wh0000gn/T/tramp-testihxoo1/Tibetan
> (བོད་སྐ????ད་) ༄༅༅༎བཀྲ????་ཤིས་བདེ་ལེགས༎ཨོཾ་མ????་ཎི་པ????དྨེ་ཧའུྂ༎',
> decode using `base64 -d >%s' failed")
>    FAILED  59/68  tramp-test41-utf8 (26.238610 sec)

Hard to debug. The "?" chars indicate, that the string isn't visible
completely in your Emacs instance (it is for me).

I've added a check in the test cases, avoiding not displayable
characters. Pushed to master.

Best regards, Michael.