Tramp: Handle symlinks to non-existing targets better

* lisp/net/tramp-gvfs.el (tramp-gvfs-do-copy-or-rename-file):
Don't use the truename.

* lisp/net/tramp-sh.el (tramp-do-copy-or-rename-file): Refactor.  Handle
symlinks.  (Bug#76678)

* lisp/net/tramp-smb.el (tramp-smb-errors): Add string.
(tramp-smb-handle-copy-file, tramp-smb-handle-rename-file):
Refactor.

* lisp/net/tramp-sudoedit.el (tramp-sudoedit-do-copy-or-rename-file):
Don't use the truename.  Handle symlinks.

* lisp/net/tramp.el (tramp-barf-if-file-missing): Accept also symlinks.
(tramp-skeleton-file-exists-p): Handle non-existing symlink targets.
(tramp-skeleton-set-file-modes-times-uid-gid): Fix typo.

* test/lisp/net/tramp-tests.el (vc-handled-backends):
Suppress only if noninteractive.
(tramp-test11-copy-file, tramp-test12-rename-file)
(tramp-test18-file-attributes, tramp-test21-file-links)
(tramp--test-check-files): Adapt tests.

1 files changed, 74 insertions, 15 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 1efafb68fbc..ccb3731fc09 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -153,7 +153,7 @@
       tramp-error-show-message-timeout nil
       tramp-persistency-file-name nil
       tramp-verbose 0
-      vc-handled-backends nil)
+      vc-handled-backends (unless noninteractive vc-handled-backends))
 
 (defconst tramp-test-name-prefix "tramp-test"
   "Prefix to use for temporary test files.")
@@ -2871,7 +2871,9 @@ This checks also `file-name-as-directory', `file-name-directory',
   (dolist (quoted (if (tramp--test-expensive-test-p) '(nil t) '(nil)))
     (let ((tmp-name1 (tramp--test-make-temp-name nil quoted))
           (tmp-name2 (tramp--test-make-temp-name nil quoted))
-          (tmp-name3 (tramp--test-make-temp-name 'local quoted)))
+          (tmp-name3 (tramp--test-make-temp-name 'local quoted))
+          (tmp-name4
+           (file-name-nondirectory (tramp--test-make-temp-name 'local quoted))))
       (dolist (source-target
                `(;; Copy on remote side.
                  (,tmp-name1 . ,tmp-name2)
@@ -2879,8 +2881,12 @@ This checks also `file-name-as-directory', `file-name-directory',
                  (,tmp-name1 . ,tmp-name3)
                  ;; Copy from local side to remote side.
                  (,tmp-name3 . ,tmp-name1)))
-        (let ((source (car source-target))
-              (target (cdr source-target)))
+        (let* ((source (car source-target))
+               (source-link
+                (expand-file-name tmp-name4 (file-name-directory source)))
+               (target (cdr source-target))
+               (target-link
+                (expand-file-name tmp-name4 (file-name-directory target))))
 
           ;; Copy simple file.
           (unwind-protect
@@ -2905,6 +2911,26 @@ This checks also `file-name-as-directory', `file-name-directory',
             (ignore-errors (delete-file source))
             (ignore-errors (delete-file target)))
 
+          ;; Copy symlinked file.
+          (unwind-protect
+              (tramp--test-ignore-make-symbolic-link-error
+               (write-region "foo" nil source-link)
+               (should (file-exists-p source-link))
+               (make-symbolic-link tmp-name4 source)
+               (should (file-exists-p source))
+               (should (string-equal (file-symlink-p source) tmp-name4))
+               (copy-file source target)
+               ;; Some backends like tramp-gvfs.el do not create the
+               ;; link on the target.
+               (when (file-symlink-p target)
+                 (should (string-equal (file-symlink-p target) tmp-name4))))
+
+            ;; Cleanup.
+            (ignore-errors (delete-file source))
+            (ignore-errors (delete-file source-link))
+            (ignore-errors (delete-file target))
+            (ignore-errors (delete-file target-link)))
+
           ;; Copy file to directory.
           (unwind-protect
               ;; This doesn't work on FTP.
@@ -2980,7 +3006,9 @@ This checks also `file-name-as-directory', `file-name-directory',
   (dolist (quoted  (if (tramp--test-expensive-test-p) '(nil t) '(nil)))
     (let ((tmp-name1 (tramp--test-make-temp-name nil quoted))
           (tmp-name2 (tramp--test-make-temp-name nil quoted))
-          (tmp-name3 (tramp--test-make-temp-name 'local quoted)))
+          (tmp-name3 (tramp--test-make-temp-name 'local quoted))
+          (tmp-name4
+           (file-name-nondirectory (tramp--test-make-temp-name 'local quoted))))
       (dolist (source-target
                `(;; Rename on remote side.
                  (,tmp-name1 . ,tmp-name2)
@@ -2988,8 +3016,12 @@ This checks also `file-name-as-directory', `file-name-directory',
                  (,tmp-name1 . ,tmp-name3)
                  ;; Rename from local side to remote side.
                  (,tmp-name3 . ,tmp-name1)))
-        (let ((source (car source-target))
-              (target (cdr source-target)))
+        (let* ((source (car source-target))
+               (source-link
+                (expand-file-name tmp-name4 (file-name-directory source)))
+               (target (cdr source-target))
+               (target-link
+                (expand-file-name tmp-name4 (file-name-directory target))))
 
           ;; Rename simple file.
           (unwind-protect
@@ -3018,6 +3050,27 @@ This checks also `file-name-as-directory', `file-name-directory',
             (ignore-errors (delete-file source))
             (ignore-errors (delete-file target)))
 
+          ;; Rename symlinked file.
+          (unwind-protect
+              (tramp--test-ignore-make-symbolic-link-error
+               (write-region "foo" nil source-link)
+               (should (file-exists-p source-link))
+               (make-symbolic-link tmp-name4 source)
+               (should (file-exists-p source))
+               (should (string-equal (file-symlink-p source) tmp-name4))
+               (rename-file source target)
+               (should-not (file-exists-p source))
+               ;; Some backends like tramp-gvfs.el do not create the
+               ;; link on the target.
+               (when (file-symlink-p target)
+                 (should (string-equal (file-symlink-p target) tmp-name4))))
+
+            ;; Cleanup.
+            (ignore-errors (delete-file source))
+            (ignore-errors (delete-file source-link))
+            (ignore-errors (delete-file target))
+            (ignore-errors (delete-file target-link)))
+
           ;; Rename file to directory.
           (unwind-protect
               (progn
@@ -3814,6 +3867,18 @@ This tests also `access-file', `file-readable-p',
                  (if quoted #'file-name-quote #'identity)
                  (file-attribute-type attr))
                 (file-remote-p (file-truename tmp-name1) 'localname)))
+              (delete-file tmp-name2)
+
+              ;; A non-existent link target makes the file unaccessible.
+              (make-symbolic-link "error" tmp-name2)
+              (should (file-symlink-p tmp-name2))
+              (should-error
+               (access-file tmp-name2 "error")
+               :type 'file-missing)
+              ;; `file-ownership-preserved-p' should return t for
+              ;; symlinked files to a non-existing target.
+              (when test-file-ownership-preserved-p
+                (should (file-ownership-preserved-p tmp-name2 'group)))
               (delete-file tmp-name2))
 
             ;; Check, that "//" in symlinks are handled properly.
@@ -4463,13 +4528,11 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
                (make-symbolic-link tmp-name1 tmp-name2)
                (should (file-symlink-p tmp-name1))
                (should (file-symlink-p tmp-name2))
-               (should-not (file-regular-p tmp-name1))
-               (should-not (file-regular-p tmp-name2))
                (should-error
-                (file-truename tmp-name1)
+                (file-regular-p tmp-name1)
                 :type 'file-error)
                (should-error
-                (file-truename tmp-name2)
+                (file-regular-p tmp-name2)
                 :type 'file-error))))
 
         ;; Cleanup.
@@ -7390,10 +7453,6 @@ This requires restrictions of file name syntax."
                      (if quoted #'file-name-quote #'identity)
                      (file-attribute-type (file-attributes file3)))
                     (file-remote-p (file-truename file1) 'localname)))
-                  ;; Check file contents.
-                  (with-temp-buffer
-                    (insert-file-contents file3)
-                    (should (string-equal (buffer-string) elt)))
                   (delete-file file3))))
 
             ;; Check file names.