Fix Bug#29579

* lisp/files.el (file-name-non-special):
Inhibit `file-name-handler-alist' only for some operations.
Add missing operations.  (Bug#29579)

* lisp/net/tramp-compat.el (tramp-compat-file-name-quote):
Do not quote if it is quoted already.

* lisp/net/tramp-smb.el (tramp-smb-handle-insert-directory):
Use `copy-tree' but `copy-sequence'.

* lisp/net/tramp.el (tramp-handle-file-truename): Handle several
trailing slashes correctly.

* test/lisp/net/tramp-tests.el (tramp-test11-copy-file)
(tramp-test12-rename-file, tramp-test24-file-acl)
(tramp-test25-file-selinux, tramp--test-check-files):
Handle also quoted file names.
(tramp-test21-file-links): Fix file name quoting test.
(tramp-test24-file-acl): Be more robust for "smb" method.
(tramp-test35-make-auto-save-file-name): Enable hidden test cases.

5 files changed, 71 insertions, 58 deletions

diff --git a/lisp/files.el b/lisp/files.el
index a7ad40b76cd..8045ba5c22b 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -6956,60 +6956,67 @@ only these files will be asked to be saved."
 ;; We depend on being the last handler on the list,
 ;; so that anything else which does need handling
 ;; has been handled already.
-;; So it is safe for us to inhibit *all* magic file name handlers.
+;; So it is safe for us to inhibit *all* magic file name handlers for
+;; operations, which return a file name.  See Bug#29579.
 
 (defun file-name-non-special (operation &rest arguments)
-  (let ((file-name-handler-alist nil)
-        (default-directory
-          ;; Some operations respect file name handlers in
-          ;; `default-directory'.  Because core function like
-          ;; `call-process' don't care about file name handlers in
-          ;; `default-directory', we here have to resolve the
-          ;; directory into a local one.  For `process-file',
-          ;; `start-file-process', and `shell-command', this fixes
-          ;; Bug#25949.
-          (if (memq operation '(insert-directory process-file start-file-process
-                                                 shell-command))
-              (directory-file-name
-               (expand-file-name
-                (unhandled-file-name-directory default-directory)))
-            default-directory))
-        ;; Get a list of the indices of the args which are file names.
-        (file-arg-indices
-         (cdr (or (assq operation
-                        ;; The first six are special because they
-                        ;; return a file name.  We want to include the /:
-                        ;; in the return value.
-                        ;; So just avoid stripping it in the first place.
-                        '((expand-file-name . nil)
-                          (file-name-directory . nil)
-                          (file-name-as-directory . nil)
-                          (directory-file-name . nil)
-                          (file-name-sans-versions . nil)
-                          (find-backup-file-name . nil)
-                          ;; `identity' means just return the first arg
-                          ;; not stripped of its quoting.
-                          (substitute-in-file-name identity)
-                          ;; `add' means add "/:" to the result.
-                          (file-truename add 0)
-                          (insert-file-contents insert-file-contents 0)
-                          ;; `unquote-then-quote' means set buffer-file-name
-                          ;; temporarily to unquoted filename.
-                          (verify-visited-file-modtime unquote-then-quote)
-                          ;; List the arguments which are filenames.
-                          (file-name-completion 1)
-                          (file-name-all-completions 1)
-                          (write-region 2 5)
-                          (rename-file 0 1)
-                          (copy-file 0 1)
-                          (make-symbolic-link 0 1)
-                          (add-name-to-file 0 1)))
-                  ;; For all other operations, treat the first argument only
-                  ;; as the file name.
-                  '(nil 0))))
-        method
-        ;; Copy ARGUMENTS so we can replace elements in it.
-        (arguments (copy-sequence arguments)))
+  (let* ((op-returns-file-name-list
+          '(expand-file-name file-name-directory file-name-as-directory
+                             directory-file-name file-name-sans-versions
+                             find-backup-file-name file-remote-p))
+         (file-name-handler-alist
+          (and
+           (not (memq operation op-returns-file-name-list))
+           file-name-handler-alist))
+         (default-directory
+           ;; Some operations respect file name handlers in
+           ;; `default-directory'.  Because core function like
+           ;; `call-process' don't care about file name handlers in
+           ;; `default-directory', we here have to resolve the
+           ;; directory into a local one.  For `process-file',
+           ;; `start-file-process', and `shell-command', this fixes
+           ;; Bug#25949.
+           (if (memq operation
+                     '(insert-directory process-file start-file-process
+                                        shell-command))
+               (directory-file-name
+                (expand-file-name
+                 (unhandled-file-name-directory default-directory)))
+             default-directory))
+         ;; Get a list of the indices of the args which are file names.
+         (file-arg-indices
+          (cdr (or (assq operation
+                         ;; The first seven are special because they
+                         ;; return a file name.  We want to include the /:
+                         ;; in the return value.
+                         ;; So just avoid stripping it in the first place.
+                         (append
+                          (mapcar 'list op-returns-file-name-list)
+                          '(;; `identity' means just return the first arg
+                            ;; not stripped of its quoting.
+                            (substitute-in-file-name identity)
+                            ;; `add' means add "/:" to the result.
+                            (file-truename add 0)
+                            (insert-file-contents insert-file-contents 0)
+                            ;; `unquote-then-quote' means set buffer-file-name
+                            ;; temporarily to unquoted filename.
+                            (verify-visited-file-modtime unquote-then-quote)
+                            ;; List the arguments which are filenames.
+                            (file-name-completion 1)
+                            (file-name-all-completions 1)
+                            (write-region 2 5)
+                            (rename-file 0 1)
+                            (copy-file 0 1)
+                            (copy-directory 0 1)
+                            (file-in-directory-p 0 1)
+                            (make-symbolic-link 0 1)
+                            (add-name-to-file 0 1))))
+                   ;; For all other operations, treat the first argument only
+                   ;; as the file name.
+                   '(nil 0))))
+         method
+         ;; Copy ARGUMENTS so we can replace elements in it.
+         (arguments (copy-sequence arguments)))
     (if (symbolp (car file-arg-indices))
         (setq method (pop file-arg-indices)))
     ;; Strip off the /: from the file names that have it.
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index 9326f7b1864..9cdfc065128 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -210,8 +210,10 @@ If NAME is a remote file name, check the local part of NAME."
     (defsubst tramp-compat-file-name-quote (name)
       "Add the quotation prefix \"/:\" to file NAME.
 If NAME is a remote file name, the local part of NAME is quoted."
-      (concat
-       (file-remote-p name) "/:" (or (file-remote-p name 'localname) name))))
+      (if (tramp-compat-file-name-quoted-p name)
+          name
+        (concat
+         (file-remote-p name) "/:" (or (file-remote-p name 'localname) name)))))
 
   (if (fboundp 'file-name-unquote)
       (defalias 'tramp-compat-file-name-unquote 'file-name-unquote)
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index acb5a12ba2a..14c1a4049aa 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -1036,6 +1036,7 @@ of command line.")
     (load . tramp-handle-load)
     (make-auto-save-file-name . tramp-handle-make-auto-save-file-name)
     (make-directory . tramp-sh-handle-make-directory)
+    ;; `make-directory-internal' performed by default handler.
     (make-nearby-temp-file . tramp-handle-make-nearby-temp-file)
     (make-symbolic-link . tramp-sh-handle-make-symbolic-link)
     (process-file . tramp-sh-handle-process-file)
diff --git a/lisp/net/tramp-smb.el b/lisp/net/tramp-smb.el
index eb0d6b50731..a4d4b4e0bcf 100644
--- a/lisp/net/tramp-smb.el
+++ b/lisp/net/tramp-smb.el
@@ -437,7 +437,7 @@ pass to the OPERATION."
                 (delete-directory tmpdir 'recursive))))
 
            ;; We can copy recursively.
-           ;; Does not work reliably.
+           ;; TODO: Does not work reliably.
            (nil ;(and (or t1 t2) (tramp-smb-get-cifs-capabilities v))
             (when (and (file-directory-p newname)
                        (not (string-equal (file-name-nondirectory dirname)
@@ -1015,7 +1015,7 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
       (save-match-data
         (let ((base (file-name-nondirectory filename))
               ;; We should not destroy the cache entry.
-              (entries (copy-sequence
+              (entries (copy-tree
                         (tramp-smb-get-file-entries
                          (file-name-directory filename))))
               (avail (get-free-disk-space filename))
@@ -1441,7 +1441,7 @@ component is used as the target of the symlink."
                 (tramp-set-connection-property
                  v "process-buffer" (current-buffer))
 
-                ;; Use an asynchronous processes.  By this, password can
+                ;; Use an asynchronous process.  By this, password can
                 ;; be handled.
                 (let ((p (apply
                           'start-process
@@ -1456,6 +1456,9 @@ component is used as the target of the symlink."
                   (set-process-query-on-exit-flag p nil)
                   (tramp-process-actions p v nil tramp-smb-actions-set-acl)
                   (goto-char (point-max))
+                  ;; This is meant for traces, and returning from the
+                  ;; function.  No error is propagated outside, due to
+                  ;; the `ignore-errors' closure.
                   (unless (re-search-backward "tramp_exit_status [0-9]+" nil t)
                     (tramp-error
                      v 'file-error
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 433baed6ed6..2fdc651a372 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3217,7 +3217,7 @@ User is always nil."
              (tramp-error
               v1 'file-error
               "Maximum number (%d) of symlinks exceeded" numchase-limit)))
-         result))
+         (directory-file-name result)))
 
      ;; Preserve trailing "/".
      (if (string-equal (file-name-nondirectory filename) "") "/" ""))))