Make subprocess functions resolve the default directory

`call-process' doesn't respect file name handlers in
`default-directory', so `file-name-non-special' has to resolve them
for `process-file', `start-file-process', and
`shell-command' (Bug#25949).

* lisp/files.el (file-name-non-special): Also resolve default
directory for 'process-file', 'start-file-process', and
'shell-command'.
* test/lisp/files-tests.el
(files-tests--file-name-non-special--subprocess): Add unit test.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/lisp/files-tests.el b/test/lisp/files-tests.el
index 9d456c512b0..80bbeb1bc54 100644
--- a/test/lisp/files-tests.el
+++ b/test/lisp/files-tests.el
@@ -243,5 +243,13 @@ be $HOME."
                          (concat "/:/:" subdir)))))
       (delete-directory dir 'recursive))))
 
+(ert-deftest files-tests--file-name-non-special--subprocess ()
+  "Check that Bug#25949 is fixed."
+  (skip-unless (executable-find "true"))
+  (should (eq (let ((default-directory "/:/")) (process-file "true")) 0))
+  (should (processp (let ((default-directory "/:/"))
+                      (start-file-process "foo" nil "true"))))
+  (should (eq (let ((default-directory "/:/")) (shell-command "true")) 0)))
+
 (provide 'files-tests)
 ;;; files-tests.el ends here