Improve backward compatibility of Tramp

* lisp/net/tramp-adb.el (tramp-adb-handle-exec-path):
* lisp/net/tramp-sh.el (tramp-sh-handle-exec-path): Use ´file-remote-p'.
(tramp-get-ls-command-with): Handle busybox specially.

* test/lisp/net/tramp-tests.el (tramp-test34-exec-path): Check for
`fboundp'.  Use `file-remote-p'.  Hide compiler warning for older
Emacsen.

1 files changed, 12 insertions, 8 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index df07a8f1b89..f2d9b0ab47e 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -4021,13 +4021,15 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
       (put 'explicit-shell-file-name 'permanent-local nil)
       (kill-buffer "*shell*"))))
 
-;; The function was introduced in Emacs 27.1.
+;; `exec-path' was introduced in Emacs 27.1.  `executable-find' has
+;; changed the number of parameters, so we use `apply' for older
+;; Emacsen.
 (ert-deftest tramp-test34-exec-path ()
   "Check `exec-path' and `executable-find'."
   (skip-unless (tramp--test-enabled))
   (skip-unless (or (tramp--test-adb-p) (tramp--test-sh-p)))
   ;; Since Emacs 27.1.
-  (skip-unless (boundp 'exec-path))
+  (skip-unless (fboundp 'exec-path))
 
   (let ((tmp-name (tramp--test-make-temp-name))
         (default-directory tramp-test-temporary-file-directory))
@@ -4038,9 +4040,9 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
           (should
            (string-equal
             (car (last (with-no-warnings (exec-path))))
-            (file-local-name default-directory)))
+            (file-remote-p default-directory 'localname)))
           ;; The shell "sh" shall always exist.
-          (should (executable-find "sh" 'remote))
+          (should (apply 'executable-find '("sh" remote)))
           ;; Since the last element in `exec-path' is the current
           ;; directory, an executable file in that directory will be
           ;; found.
@@ -4050,11 +4052,13 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
           (should (file-executable-p tmp-name))
           (should
            (string-equal
-            (executable-find (file-name-nondirectory tmp-name) 'remote)
-            (file-local-name tmp-name)))
+            (apply
+             'executable-find `(,(file-name-nondirectory tmp-name) remote))
+            (file-remote-p tmp-name 'localname)))
           (should-not
-           (executable-find
-            (concat (file-name-nondirectory tmp-name) "foo") 'remote)))
+           (apply
+            'executable-find
+            `(,(concat (file-name-nondirectory tmp-name) "foo") remote))))
 
       ;; Cleanup.
       (ignore-errors (delete-file tmp-name)))))