The patch(es) can be found in my previous message[2] (along with some
context and rationale).  Let me know if there is anything I can do to
help with the review.

Thank you for your time.


[1] Contents of the details buffer:

    > If your command contains occurrences of ‘*’ surrounded by
    > whitespace, ‘dired-do-shell-command’ substitutes them for the
    > entire file list to process.  Otherwise, if your command contains
    > occurrences of ‘?’ surrounded by whitespace or ‘`’, Dired will
    > run the command once for each file, substituting ‘?’ for each
    > file name.
    >
    > Your command contains occurrences of ‘?’ that will not be
    > substituted, and will be passed through normally to the shell.
    >
    > sed 's/?/!/'

    '?' is highlighted with the warning face.

[2] https://debbugs.gnu.org/cgi/bugreport.cgi?bug=35564#157