From da758046da74e33273265cd2e72a8aa1a0c9c7e3 Mon Sep 17 00:00:00 2001 From: Mattias Engdegård Date: Sun, 24 Feb 2019 22:12:52 +0100 Subject: rx: fix `or' ordering by adding argument to regexp-opt The rx `or' form may reorder its arguments in an unpredictable way, contrary to user expectation, since it sometimes uses `regexp-opt'. Add a NOREORDER option to `regexp-opt' for preventing it from producing a reordered regexp (Bug#34641). * doc/lispref/searching.texi (Regular Expression Functions): * etc/NEWS (Lisp Changes in Emacs 27.1): Describe the new regexp-opt NOREORDER argument. * lisp/emacs-lisp/regexp-opt.el (regexp-opt): Add NOREORDER. Make no attempt at regexp improvement if the set of strings contains a prefix of another string. (regexp-opt--contains-prefix): New. * lisp/emacs-lisp/rx.el (rx-or): Call regexp-opt with NOREORDER. * test/lisp/emacs-lisp/rx-tests.el: Test rx `or' form match order. --- test/lisp/emacs-lisp/rx-tests.el | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'test/lisp/emacs-lisp') diff --git a/test/lisp/emacs-lisp/rx-tests.el b/test/lisp/emacs-lisp/rx-tests.el index e14feda347f..fa3d9b0d5ea 100644 --- a/test/lisp/emacs-lisp/rx-tests.el +++ b/test/lisp/emacs-lisp/rx-tests.el @@ -92,5 +92,18 @@ (*? "e") (+? "f") (\?? "g") (?? "h")))) "a*b+c?d?e*?f+?g??h??"))) +(ert-deftest rx-or () + ;; Test or-pattern reordering (Bug#34641). + (let ((s "abc")) + (should (equal (and (string-match (rx (or "abc" "ab" "a")) s) + (match-string 0 s)) + "abc")) + (should (equal (and (string-match (rx (or "ab" "abc" "a")) s) + (match-string 0 s)) + "ab")) + (should (equal (and (string-match (rx (or "a" "ab" "abc")) s) + (match-string 0 s)) + "a")))) + (provide 'rx-tests) ;; rx-tests.el ends here. -- cgit v1.2.3