Improve symlinks for Tramp

* lisp/files.el (files--splice-dirname-file): Quote whole file.

* lisp/net/tramp-sh.el (tramp-sh-handle-make-symbolic-link):
Do not expand TARGET, it could be remote.
(tramp-sh-handle-file-truename): Check for cyclic symlink also
in case of readlink.  Quote result if it looks remote.
(tramp-sh-handle-file-local-copy): Use `file-truename'.

* test/lisp/net/tramp-tests.el (tramp-test08-file-local-copy)
(tramp-test09-insert-file-contents): Test also file missing.
(tramp-test21-file-links): Extend test.

1 files changed, 76 insertions, 14 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 201ac10dcc2..662163f3fec 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -1762,7 +1762,13 @@ This checks also `file-name-as-directory', `file-name-directory',
                   (tramp-copy-size-limit 4)
                   (tramp-inline-compress-start-size 2))
               (delete-file tmp-name2)
-              (should (setq tmp-name2 (file-local-copy tmp-name1)))))
+              (should (setq tmp-name2 (file-local-copy tmp-name1))))
+            ;; Error case.
+            (delete-file tmp-name1)
+            (delete-file tmp-name2)
+            (should-error
+             (setq tmp-name2 (file-local-copy tmp-name1))
+             :type tramp-file-missing))
 
         ;; Cleanup.
         (ignore-errors
@@ -1776,19 +1782,23 @@ This checks also `file-name-as-directory', `file-name-directory',
   (dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
     (let ((tmp-name (tramp--test-make-temp-name nil quoted)))
       (unwind-protect
-          (progn
+          (with-temp-buffer
             (write-region "foo" nil tmp-name)
-            (with-temp-buffer
-              (insert-file-contents tmp-name)
-              (should (string-equal (buffer-string) "foo"))
-              (insert-file-contents tmp-name)
-              (should (string-equal (buffer-string) "foofoo"))
-              ;; Insert partly.
-              (insert-file-contents tmp-name nil 1 3)
-              (should (string-equal (buffer-string) "oofoofoo"))
-              ;; Replace.
-              (insert-file-contents tmp-name nil nil nil 'replace)
-              (should (string-equal (buffer-string) "foo"))))
+            (insert-file-contents tmp-name)
+            (should (string-equal (buffer-string) "foo"))
+            (insert-file-contents tmp-name)
+            (should (string-equal (buffer-string) "foofoo"))
+            ;; Insert partly.
+            (insert-file-contents tmp-name nil 1 3)
+            (should (string-equal (buffer-string) "oofoofoo"))
+            ;; Replace.
+            (insert-file-contents tmp-name nil nil nil 'replace)
+            (should (string-equal (buffer-string) "foo"))
+            ;; Error case.
+            (delete-file tmp-name)
+            (should-error
+             (insert-file-contents tmp-name)
+             :type tramp-file-missing))
 
         ;; Cleanup.
         (ignore-errors (delete-file tmp-name))))))
@@ -2681,6 +2691,16 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
             (should
              (string-equal (file-truename tmp-name1) (file-truename tmp-name2)))
             (should (file-equal-p tmp-name1 tmp-name2))
+            ;; Symbolic links could look like a remote file name.
+            ;; They must be quoted then.
+            (delete-file tmp-name2)
+            (make-symbolic-link "/penguin:motd:" tmp-name2)
+            (should (file-symlink-p tmp-name2))
+            (should
+             (string-equal
+              (file-truename tmp-name2)
+              (tramp-compat-file-name-quote
+               (concat (file-remote-p tmp-name2) "/penguin:motd:"))))
             ;; `tmp-name3' is a local file name.
             (make-symbolic-link tmp-name1 tmp-name3)
             (should (file-symlink-p tmp-name3))
@@ -2698,6 +2718,48 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
           (delete-file tmp-name2)
           (delete-file tmp-name3)))
 
+      ;; Symbolic links could be nested.
+      (unwind-protect
+          (tramp--test-ignore-make-symbolic-link-error
+            (make-directory tmp-name1)
+            (should (file-directory-p tmp-name1))
+            (let* ((tramp-test-temporary-file-directory
+                    (file-truename tmp-name1))
+                   (tmp-name2 (tramp--test-make-temp-name nil quoted))
+                   (tmp-name3 tmp-name2)
+                   (number-nesting 50))
+              (dotimes (_ number-nesting)
+                (make-symbolic-link
+                 tmp-name3
+                 (setq tmp-name3 (tramp--test-make-temp-name nil quoted))))
+              (should
+               (string-equal
+                (file-truename tmp-name2)
+                (file-truename tmp-name3)))
+              (should-error
+               (with-temp-buffer (insert-file-contents tmp-name2))
+               :type tramp-file-missing)
+              (should-error
+               (with-temp-buffer (insert-file-contents tmp-name3))
+               :type tramp-file-missing)))
+
+        ;; Cleanup.
+        (ignore-errors (delete-directory tmp-name1 'recursive)))
+
+      ;; Detect cyclic symbolic links.
+      (unwind-protect
+          (tramp--test-ignore-make-symbolic-link-error
+            (make-symbolic-link tmp-name2 tmp-name1)
+            (should (file-symlink-p tmp-name1))
+            (make-symbolic-link tmp-name1 tmp-name2)
+            (should (file-symlink-p tmp-name2))
+            (should-error (file-truename tmp-name1) :type 'file-error))
+
+        ;; Cleanup.
+        (ignore-errors
+          (delete-file tmp-name1)
+          (delete-file tmp-name2)))
+
       ;; `file-truename' shall preserve trailing link of directories.
       (unless (file-symlink-p tramp-test-temporary-file-directory)
         (let* ((dir1 (directory-file-name tramp-test-temporary-file-directory))
@@ -4019,7 +4081,7 @@ process sentinels.  They shall not disturb each other."
             ;; Create temporary buffers.  The number of buffers
             ;; corresponds to the number of processes; it could be
             ;; increased in order to make pressure on Tramp.
-            (dotimes (_i number-proc)
+            (dotimes (_ number-proc)
               (setq buffers (cons (generate-new-buffer "foo") buffers)))
 
             ;; Open asynchronous processes.  Set process filter and sentinel.