bug#34318: 26.1.90; Strange behavior of two line message with running shell

[martin rudalics]

> What is the value of print-escape-newlines?

So it's

commit a92e7b4ef6915e079a97e4e33e45b11508170cb1
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Wed Apr 25 12:20:04 2018 -0700

    Don’t set print-escape-newlines in the minibuffer

    This appears to be an unnecessary and possibly-confusing
    revenant from ancient code (Bug#31251).  See thread containing:
    https://lists.gnu.org/r/emacs-devel/2018-04/msg00654.html
    * src/minibuf.c (read_minibuf): Do not set print-escape-newlines.
    * src/print.c (syms_of_print): Do not defsym print-escape-newlines
    or print-escape-control-characters, as these symbols are not used
    in C code.

that fixed the behavior for Emacs 27.  Since it apparently worked
until Emacs 25 we have a regression in Emacs 26 though.

Thanks for spotting it, martin