Revert a1bbc49015 (Bug#30243), do not merge

* lisp/files.el:
* test/lisp/net/tramp-tests.el: Revert a1bbc49015.  (Bug#30243)

lisp/files.el

@@ -6978,67 +6978,60 @@ 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 for
-;; operations, which return a file name.  See Bug#29579.
+;; So it is safe for us to inhibit *all* magic file name handlers.
 
 (defun file-name-non-special (operation &rest 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)))
+  (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)))
     (if (symbolp (car file-arg-indices))
 	(setq method (pop file-arg-indices)))
     ;; Strip off the /: from the file names that have it.

test/lisp/net/tramp-tests.el

@@ -1882,9 +1882,9 @@ This checks also `file-name-as-directory', `file-name-directory',
   "Check `copy-file'."
   (skip-unless (tramp--test-enabled))
 
-  ;; `filename-non-special' has been fixed in Emacs 26.1, see Bug#29579.
-  (dolist (quoted (if (and tramp--test-expensive-test (tramp--test-emacs26-p))
-		      '(nil t) '(nil)))
+  ;; TODO: The quoted case does not work.  Copy local file to remote.
+  ;;(dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
+  (let (quoted)
     (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)))
@@ -1984,9 +1984,9 @@ This checks also `file-name-as-directory', `file-name-directory',
   "Check `rename-file'."
   (skip-unless (tramp--test-enabled))
 
-  ;; `filename-non-special' has been fixed in Emacs 26.1, see Bug#29579.
-  (dolist (quoted (if (and tramp--test-expensive-test (tramp--test-emacs26-p))
-		      '(nil t) '(nil)))
+  ;; TODO: The quoted case does not work.
+  ;;(dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
+  (let (quoted)
     (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)))
@@ -2810,11 +2810,7 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 	    ;; Symbolic links could look like a remote file name.
 	    ;; They must be quoted then.
 	    (delete-file tmp-name2)
-	    (make-symbolic-link
-	     (funcall
-	      (if quoted 'tramp-compat-file-name-unquote 'identity)
-	      "/penguin:motd:")
-	     tmp-name2)
+	    (make-symbolic-link "/penguin:motd:" tmp-name2)
 	    (should (file-symlink-p tmp-name2))
 	    (should
 	     (string-equal
@@ -2829,7 +2825,7 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 	    ;; We must unquote it.
 	    (should
 	     (string-equal
-	      (tramp-compat-file-name-unquote (file-truename tmp-name1))
+	      (file-truename tmp-name1)
 	      (tramp-compat-file-name-unquote (file-truename tmp-name3)))))
 
 	;; Cleanup.
@@ -2955,9 +2951,9 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
   (skip-unless (tramp--test-enabled))
   (skip-unless (file-acl tramp-test-temporary-file-directory))
 
-  ;; `filename-non-special' has been fixed in Emacs 26.1, see Bug#29579.
-  (dolist (quoted (if (and tramp--test-expensive-test (tramp--test-emacs26-p))
-		      '(nil t) '(nil)))
+  ;; TODO: The quoted case does not work.  Copy local file to remote.
+  ;;(dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
+  (let (quoted)
     (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)))
@@ -3033,9 +3029,9 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
    (not (equal (file-selinux-context tramp-test-temporary-file-directory)
 	       '(nil nil nil nil))))
 
-  ;; `filename-non-special' has been fixed in Emacs 26.1, see Bug#29579.
-  (dolist (quoted (if (and tramp--test-expensive-test (tramp--test-emacs26-p))
-		      '(nil t) '(nil)))
+  ;; TODO: The quoted case does not work.  Copy local file to remote.
+  ;;(dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
+  (let (quoted)
     (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)))
@@ -4086,9 +4082,9 @@ This requires restrictions of file name syntax."
 
 (defun tramp--test-check-files (&rest files)
   "Run a simple but comprehensive test over every file in FILES."
-  ;; `filename-non-special' has been fixed in Emacs 26.1, see Bug#29579.
-  (dolist (quoted (if (and tramp--test-expensive-test (tramp--test-emacs26-p))
-		      '(nil t) '(nil)))
+  ;; TODO: The quoted case does not work.
+  ;;(dolist (quoted (if tramp--test-expensive-test '(nil t) '(nil)))
+  (let (quoted)
     ;; We must use `file-truename' for the temporary directory,
     ;; because it could be located on a symlinked directory.  This
     ;; would let the test fail.