Fix Tramp part of Bug#28156

* lisp/files.el (file-name-non-special): Use `file-name-quote'
instead prefixing "/:", the file could already be quoted.

* lisp/net/tramp.el (tramp-error): Handle null arguments.
(tramp-handle-make-symbolic-link):
* lisp/net/tramp-sh.el (tramp-sh-handle-make-symbolic-link)
(tramp-sh-handle-add-name-to-file):
* lisp/net/tramp-smb.el (tramp-smb-handle-add-name-to-file)
(tramp-smb-handle-make-symbolic-link): Adapt implementation to
stronger semantics in Emacs.  (Bug#28156)

* test/lisp/net/tramp-tests.el (tramp-test21-file-links):
Extend test.

1 files changed, 24 insertions, 6 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 55f4b52ccdf..3dbb522a7cd 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2587,16 +2587,19 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
                 (not (string-equal (error-message-string err)
                                    "make-symbolic-link not supported")))))
             (should (file-symlink-p tmp-name2))
-            (should-error (make-symbolic-link tmp-name1 tmp-name2))
+            (should-error (make-symbolic-link tmp-name1 tmp-name2)
+                          :type 'file-already-exists)
             (make-symbolic-link tmp-name1 tmp-name2 'ok-if-already-exists)
             (should (file-symlink-p tmp-name2))
             ;; `tmp-name3' is a local file name.
-            (should-error (make-symbolic-link tmp-name1 tmp-name3)))
+            (make-symbolic-link tmp-name1 tmp-name3)
+            (should (file-symlink-p tmp-name3)))
 
         ;; Cleanup.
         (ignore-errors
           (delete-file tmp-name1)
-          (delete-file tmp-name2)))
+          (delete-file tmp-name2)
+          (delete-file tmp-name3)))
 
       ;; Check `add-name-to-file'.
       (unwind-protect
@@ -2605,7 +2608,8 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
             (should (file-exists-p tmp-name1))
             (add-name-to-file tmp-name1 tmp-name2)
             (should-not (file-symlink-p tmp-name2))
-            (should-error (add-name-to-file tmp-name1 tmp-name2))
+            (should-error (add-name-to-file tmp-name1 tmp-name2)
+                          :type 'file-already-exists)
             (add-name-to-file tmp-name1 tmp-name2 'ok-if-already-exists)
             (should-not (file-symlink-p tmp-name2))
             ;; `tmp-name3' is a local file name.
@@ -2626,10 +2630,24 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
             (should-not (string-equal tmp-name2 (file-truename tmp-name2)))
             (should
              (string-equal (file-truename tmp-name1) (file-truename tmp-name2)))
-            (should (file-equal-p tmp-name1 tmp-name2)))
+            (should (file-equal-p tmp-name1 tmp-name2))
+            ;; `tmp-name3' is a local file name.
+            (make-symbolic-link tmp-name1 tmp-name3)
+            (should (file-symlink-p tmp-name3))
+            (should-not (string-equal tmp-name3 (file-truename tmp-name3)))
+            ;; `file-truename' returns a quoted file name for `tmp-name3'.
+            ;; We must unquote it.
+            (should
+             (string-equal
+              (file-truename tmp-name1)
+              (funcall
+               'tramp-compat-file-name-unquote (file-truename tmp-name3)))))
+
+        ;; Cleanup.
         (ignore-errors
           (delete-file tmp-name1)
-          (delete-file tmp-name2)))
+          (delete-file tmp-name2)
+          (delete-file tmp-name3)))
 
       ;; `file-truename' shall preserve trailing link of directories.
       (unless (file-symlink-p tramp-test-temporary-file-directory)