From faf68f4979509cd61b5f666479b66ec5b37594d6 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sun, 20 Aug 2017 03:13:52 -0700 Subject: [PATCH] Do not munge contents of local symbolic links This lets Emacs deal with arbitrary local symlinks without mishandling their contents. For example, (progn (shell-command "ln -fs '~' 'x'") (rename-file "x" "/tmp/x")) now consistently creates a symbolic link from '/tmp/x' to '~'. Formerly, it did that only if the working directory was on the same filesystem as /tmp; otherwise, it expanded the '~' to the user's home directory. * etc/NEWS: Document the change. * src/fileio.c (Fmake_symbolic_link): Do not expand leading "~" in the target, and look for special constructs only in the new link name, not the target. (emacs_readlinkat): Do not preprend "/:" to the link target if it starts with "/" and contains ":" before NUL. * test/lisp/net/tramp-tests.el (tramp-test21-file-links): Adjust to new behavior. * test/src/fileio-tests.el (try-link): Rename from try-char, and accept a string instead of a char. All uses changed. (fileio-tests--symlink-failure): Also test leading ~, and "/:", to test the new behavior. --- etc/NEWS | 8 ++++++++ src/fileio.c | 18 ------------------ test/lisp/net/tramp-tests.el | 9 ++++++--- test/src/fileio-tests.el | 21 ++++++++++----------- 4 files changed, 24 insertions(+), 32 deletions(-) diff --git a/etc/NEWS b/etc/NEWS index 7774d75..104ee04 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -1204,6 +1204,14 @@ instead of to utf-8. Before this change, Emacs would sometimes mishandle file names containing these control characters. +++ +** 'file-attributes', 'file-symlink-p' and 'make-symbolic-link' no +longer quietly mutate the target of a local symbolic link. In +particular, 'file-attributes' and 'file-symlink-p' no longer prepend +"/:" to some targets of local symbolic links, and 'make-symbolic-link' +no longer expands '~' at the start of a link target. This change lets +Emacs access and copy arbitrary local symbolic links. + ++++ ** Module functions are now implemented slightly differently; in particular, the function 'internal--module-call' has been removed. Code that depends on undocumented internals of the module system might diff --git a/src/fileio.c b/src/fileio.c index f954ac1..ce243c3 100644 --- a/src/fileio.c +++ b/src/fileio.c @@ -2423,21 +2423,8 @@ This happens for interactive use with M-x. */) Lisp_Object encoded_target, encoded_linkname; CHECK_STRING (target); - /* If the link target has a ~, we must expand it to get - a truly valid file name. Otherwise, do not expand; - we want to permit links to relative file names. */ - if (SREF (target, 0) == '~') - target = Fexpand_file_name (target, Qnil); - linkname = expand_cp_target (target, linkname); - /* If the file name has special constructs in it, - call the corresponding file handler. */ - handler = Ffind_file_name_handler (target, Qmake_symbolic_link); - if (!NILP (handler)) - return call4 (handler, Qmake_symbolic_link, target, - linkname, ok_if_already_exists); - /* If the new link name has special constructs in it, call the corresponding file handler. */ handler = Ffind_file_name_handler (linkname, Qmake_symbolic_link); @@ -2635,11 +2622,6 @@ emacs_readlinkat (int fd, char const *filename) return Qnil; val = build_unibyte_string (buf); - if (buf[0] == '/' && strchr (buf, ':')) - { - AUTO_STRING (slash_colon, "/:"); - val = concat2 (slash_colon, val); - } if (buf != readlink_buf) xfree (buf); val = DECODE_FILE (val); diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el index 9dc276b..0740996 100644 --- a/test/lisp/net/tramp-tests.el +++ b/test/lisp/net/tramp-tests.el @@ -2538,13 +2538,16 @@ tramp--test-backtrace (should-error (make-symbolic-link tmp-name1 tmp-name2)) (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))) + ;; `tmp-name3' is a local file name, so its target is not + ;; interpreted. + (make-symbolic-link tmp-name1 tmp-name3) + (should (equal tmp-name1 (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 diff --git a/test/src/fileio-tests.el b/test/src/fileio-tests.el index 2ef1b55..5103d2f 100644 --- a/test/src/fileio-tests.el +++ b/test/src/fileio-tests.el @@ -19,14 +19,13 @@ (require 'ert) -(defun try-char (char link) - (let ((target (string char))) - (make-symbolic-link target link) - (let* ((read-link (file-symlink-p link)) - (failure (unless (string-equal target read-link) - (list 'string-equal target read-link)))) - (delete-file link) - failure))) +(defun try-link (target link) + (make-symbolic-link target link) + (let* ((read-link (file-symlink-p link)) + (failure (unless (string-equal target read-link) + (list 'string-equal target read-link)))) + (delete-file link) + failure)) (defun fileio-tests--symlink-failure () (let* ((dir (make-temp-file "fileio" t)) @@ -36,9 +35,9 @@ fileio-tests--symlink-failure (char 0)) (while (and (not failure) (< char 127)) (setq char (1+ char)) - (unless (= char ?~) - (setq failure (try-char char link)))) - failure) + (setq failure (try-link (string char) link))) + (or failure + (try-link "/:" link))) (delete-directory dir t)))) (ert-deftest fileio-tests--odd-symlink-chars () -- 2.7.4