bug#24723: 26.0.50; minibuffer-default-add-shell-commands wrong behavior

[Mark Oteiza]

>From -Q, with a ~/.mailcap containing the line

text/plain: cat %s;

1. (read-shell-command "? " nil nil "dog")
2. M-n, minibuffer should now contain "dog", as expected
3. M-n once more, minibuffer now contains "cat dog"

minibuffer-default-add-shell-commands is treating a command as a
filename; it should not be concatenating commands together.


In GNU Emacs 26.0.50.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2016-10-17 built on logos
Repository revision: e697ccab77b1668a0781397b55b676fc4e9bc1b6