Issue #1204: fix font-name-add-files regtest (issue 573730044 by address@hidden)

[dak]

https://codereview.appspot.com/573730044/diff/583810043/input/regression/font-name-add-files.ly
File input/regression/font-name-add-files.ly (right):

https://codereview.appspot.com/573730044/diff/583810043/input/regression/font-name-add-files.ly#newcode25
input/regression/font-name-add-files.ly:25: tmpdir = #(let ((env-tmpdir
(getenv "TMPDIR")))
tmpdir = #(or (getenv "TMPDIR") "/tmp")

https://codereview.appspot.com/573730044/diff/583810043/input/regression/font-name-add-files.ly#newcode28
input/regression/font-name-add-files.ly:28: dummyname = #(port-filename
(mkstemp! (string-append tmpdir "/" "dummyfont-XXXXXX")))
This fixes the problem that mkstemp! needs a writable string since
string-append returns a newly allocated string.  Whether it's by design
or not the computer won't care, so that should fix the potential
Guile-2.x problem.

https://codereview.appspot.com/573730044/diff/583810043/input/regression/font-name-add-files.ly#newcode252
input/regression/font-name-add-files.ly:252: (if (or (equal? "." f)
No point in a functional language to write as if expressions and
procedures were different things.  Just write

(or (equal? "." f) (equal? ".." f)
    (delete-file (string-append ...)))

https://codereview.appspot.com/573730044/